From 6e385f12be56cbc83092aa036efaff03a9c02bb0 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 10 Jan 2024 16:23:58 -0500
Subject: [PATCH 01/32] update ast

---
 packages/pigeon/CHANGELOG.md                  |   4 +
 packages/pigeon/lib/ast.dart                  | 213 ++++++-
 packages/pigeon/lib/cpp_generator.dart        |  35 +-
 packages/pigeon/lib/dart_generator.dart       |  22 +-
 packages/pigeon/lib/generator.dart            | 105 +++-
 packages/pigeon/lib/generator_tools.dart      | 100 ++++
 packages/pigeon/lib/java_generator.dart       |  20 +-
 packages/pigeon/lib/kotlin_generator.dart     |  19 +-
 packages/pigeon/lib/objc_generator.dart       |  16 +-
 packages/pigeon/lib/pigeon_lib.dart           | 560 +++++++++++++++++-
 packages/pigeon/lib/swift_generator.dart      |  20 +-
 packages/pigeon/pubspec.yaml                  |   2 +-
 packages/pigeon/test/cpp_generator_test.dart  |  88 ++-
 packages/pigeon/test/dart_generator_test.dart | 170 +++---
 .../pigeon/test/generator_tools_test.dart     |  27 +-
 packages/pigeon/test/java_generator_test.dart |  87 ++-
 .../pigeon/test/kotlin_generator_test.dart    |  96 +--
 packages/pigeon/test/objc_generator_test.dart | 193 ++++--
 packages/pigeon/test/pigeon_lib_test.dart     |   8 +-
 .../pigeon/test/swift_generator_test.dart     |  84 ++-
 20 files changed, 1481 insertions(+), 388 deletions(-)

diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index 6e05728aa341..a0dbe6f8c8a3 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 16.0.1
+
+* Adds ProxyApi to AST generation.
+
 ## 16.0.0
 
 * [java] Adds `VoidResult` type for `Void` returns.
diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 9d79a781afbd..7b0e32511fae 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -29,7 +29,10 @@ class Method extends Node {
     required this.name,
     required this.returnType,
     required this.parameters,
+    required this.location,
+    this.required = false,
     this.isAsynchronous = false,
+    this.isStatic = false,
     this.offset,
     this.objcSelector = '',
     this.swiftFunction = '',
@@ -68,6 +71,18 @@ class Method extends Node {
   /// For example: [" List of documentation comments, separated by line.", ...]
   List<String> documentationComments;
 
+  /// Where the implementation of this method is located, host or Flutter.
+  ApiLocation location;
+
+  /// Whether this method is required to be implemented.
+  ///
+  /// This flag is typically used to determine whether a callback method for
+  /// a `ProxyApi` is nullable or not.
+  bool required;
+
+  /// Whether this is a static method of a ProxyApi.
+  bool isStatic;
+
   @override
   String toString() {
     final String objcSelectorStr =
@@ -78,29 +93,185 @@ class Method extends Node {
   }
 }
 
-/// Represents a collection of [Method]s that are hosted on a given [location].
-class Api extends Node {
+/// Represents a collection of [Method]s that are implemented on the platform
+/// side.
+class AstHostApi extends Api {
+  /// Parametric constructor for [AstHostApi].
+  AstHostApi({
+    required super.name,
+    required super.methods,
+    super.documentationComments = const <String>[],
+    this.dartHostTestHandler,
+  });
+
+  /// The name of the Dart test interface to generate to help with testing.
+  String? dartHostTestHandler;
+
+  @override
+  String toString() {
+    return '(HostApi name:$name methods:$methods documentationComments:$documentationComments dartHostTestHandler:$dartHostTestHandler)';
+  }
+}
+
+/// Represents a collection of [Method]s that are hosted on the Flutter side.
+class AstFlutterApi extends Api {
+  /// Parametric constructor for [AstFlutterApi].
+  AstFlutterApi({
+    required super.name,
+    required super.methods,
+    super.documentationComments = const <String>[],
+  });
+
+  @override
+  String toString() {
+    return '(FlutterApi name:$name methods:$methods documentationComments:$documentationComments)';
+  }
+}
+
+/// Represents an API that wraps a native class.
+class AstProxyApi extends Api {
+  /// Parametric constructor for [AstProxyApi].
+  AstProxyApi({
+    required super.name,
+    required super.methods,
+    super.documentationComments = const <String>[],
+    required this.constructors,
+    required this.fields,
+    this.superClassName,
+    this.interfacesNames = const <String>{},
+  });
+
+  /// List of constructors inside the API.
+  final List<Constructor> constructors;
+
+  /// List of fields inside the API.
+  List<Field> fields;
+
+  /// Name of the class this class considers the super class.
+  final String? superClassName;
+
+  /// Name of the classes this class considers to be implemented.
+  final Set<String> interfacesNames;
+
+  /// Methods implemented in the host platform language.
+  Iterable<Method> get hostMethods => methods.where(
+        (Method method) => method.location == ApiLocation.host,
+      );
+
+  /// Methods implemented in Flutter.
+  Iterable<Method> get flutterMethods => methods.where(
+        (Method method) => method.location == ApiLocation.flutter,
+      );
+
+  /// All fields that are attached.
+  ///
+  /// See [attached].
+  Iterable<Field> get attachedFields => fields.where(
+        (Field field) => field.isAttached,
+      );
+
+  /// All fields that are not attached.
+  ///
+  /// See [attached].
+  Iterable<Field> get unattachedFields => fields.where(
+        (Field field) => !field.isAttached,
+      );
+
+  @override
+  String toString() {
+    return '(ProxyApi name:$name methods:$methods documentationComments:$documentationComments superClassName:$superClassName interfacesNames:$interfacesNames)';
+  }
+}
+
+/// Represents a constructor for an API.
+class Constructor extends Node {
+  /// Parametric constructor for [Constructor].
+  Constructor({
+    required this.name,
+    required this.parameters,
+    this.offset,
+    this.swiftFunction = '',
+    this.documentationComments = const <String>[],
+  });
+
+  /// The name of the method.
+  String name;
+
+  /// The parameters passed into the [Constructor].
+  List<Parameter> parameters;
+
+  /// The offset in the source file where the field appears.
+  int? offset;
+
+  /// An override for the generated swift function signature (ex. "divideNumber(_:by:)").
+  String swiftFunction;
+
+  /// List of documentation comments, separated by line.
+  ///
+  /// Lines should not include the comment marker itself, but should include any
+  /// leading whitespace, so that any indentation in the original comment is preserved.
+  /// For example: [" List of documentation comments, separated by line.", ...]
+  List<String> documentationComments;
+
+  @override
+  String toString() {
+    final String swiftFunctionStr =
+        swiftFunction.isEmpty ? '' : ' swiftFunction:$swiftFunction';
+    return '(Constructor name:$name parameters:$parameters $swiftFunctionStr documentationComments:$documentationComments)';
+  }
+}
+
+/// Represents a field of an API.
+class Field extends NamedType {
+  /// Constructor for [Field].
+  Field({
+    required super.name,
+    required super.type,
+    super.offset,
+    super.documentationComments,
+    this.isAttached = false,
+    this.isStatic = false,
+  }) : assert(!isStatic || isAttached);
+
+  /// Whether this is an attached field for a [AstProxyApi].
+  ///
+  /// See [attached].
+  final bool isAttached;
+
+  /// Whether this is a static field of a [AstProxyApi].
+  ///
+  /// A static field must also be attached. See [attached].
+  final bool isStatic;
+
+  /// Returns a copy of [Parameter] instance with new attached [TypeDeclaration].
+  @override
+  Field copyWithType(TypeDeclaration type) {
+    return Field(
+      name: name,
+      type: type,
+      offset: offset,
+      documentationComments: documentationComments,
+      isAttached: isAttached,
+      isStatic: isStatic,
+    );
+  }
+}
+
+/// Represents a collection of [Method]s.
+sealed class Api extends Node {
   /// Parametric constructor for [Api].
   Api({
     required this.name,
-    required this.location,
     required this.methods,
-    this.dartHostTestHandler,
     this.documentationComments = const <String>[],
   });
 
   /// The name of the API.
   String name;
 
-  /// Where the API's implementation is located, host or Flutter.
-  ApiLocation location;
-
   /// List of methods inside the API.
   List<Method> methods;
 
-  /// The name of the Dart test interface to generate to help with testing.
-  String? dartHostTestHandler;
-
   /// List of documentation comments, separated by line.
   ///
   /// Lines should not include the comment marker itself, but should include any
@@ -110,7 +281,7 @@ class Api extends Node {
 
   @override
   String toString() {
-    return '(Api name:$name location:$location methods:$methods documentationComments:$documentationComments)';
+    return '(Api name:$name methods:$methods documentationComments:$documentationComments)';
   }
 }
 
@@ -123,6 +294,7 @@ class TypeDeclaration {
     required this.isNullable,
     this.associatedEnum,
     this.associatedClass,
+    this.associatedProxyApi,
     this.typeArguments = const <TypeDeclaration>[],
   });
 
@@ -132,6 +304,7 @@ class TypeDeclaration {
         isNullable = false,
         associatedEnum = null,
         associatedClass = null,
+        associatedProxyApi = null,
         typeArguments = const <TypeDeclaration>[];
 
   /// The base name of the [TypeDeclaration] (ex 'Foo' to 'Foo<Bar>?').
@@ -158,6 +331,12 @@ class TypeDeclaration {
   /// Associated [Class], if any.
   final Class? associatedClass;
 
+  /// Associated [AstProxyApi], if any.
+  final AstProxyApi? associatedProxyApi;
+
+  /// Whether the [TypeDeclaration] has an [associatedProxyApi].
+  bool get isProxyApi => associatedProxyApi != null;
+
   @override
   int get hashCode {
     // This has to be implemented because TypeDeclaration is used as a Key to a
@@ -207,11 +386,21 @@ class TypeDeclaration {
     );
   }
 
+  /// Returns duplicated `TypeDeclaration` with attached `associatedProxyApi` value.
+  TypeDeclaration copyWithProxyApi(AstProxyApi proxyApiDefinition) {
+    return TypeDeclaration(
+      baseName: baseName,
+      isNullable: isNullable,
+      associatedProxyApi: proxyApiDefinition,
+      typeArguments: typeArguments,
+    );
+  }
+
   @override
   String toString() {
     final String typeArgumentsStr =
         typeArguments.isEmpty ? '' : 'typeArguments:$typeArguments';
-    return '(TypeDeclaration baseName:$baseName isNullable:$isNullable$typeArgumentsStr isEnum:$isEnum isClass:$isClass)';
+    return '(TypeDeclaration baseName:$baseName isNullable:$isNullable$typeArgumentsStr isEnum:$isEnum isClass:$isClass isProxyApi:$isProxyApi)';
   }
 }
 
diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 5247f424052e..2ec8ccd00833 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -175,7 +175,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
         indent, anEnum.documentationComments, _docCommentSpec);
     indent.write('enum class ${anEnum.name} ');
     indent.addScoped('{', '};', () {
-      enumerate(anEnum.members, (int index, final EnumMember member) {
+      enumerate(anEnum.members, (int index, EnumMember member) {
         addDocumentationComments(
             indent, member.documentationComments, _docCommentSpec);
         indent.writeln(
@@ -191,14 +191,21 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi = root.apis
+        .whereType<AstHostApi>()
+        .any((Api api) => api.methods.isNotEmpty);
+    final bool hasFlutterApi = root.apis
+        .whereType<AstFlutterApi>()
+        .any((Api api) => api.methods.isNotEmpty);
 
     _writeFlutterError(indent);
     if (hasHostApi) {
-      _writeErrorOr(indent, friends: root.apis.map((Api api) => api.name));
+      _writeErrorOr(
+        indent,
+        friends: root.apis
+            .where((Api api) => api is AstFlutterApi || api is AstHostApi)
+            .map((Api api) => api.name),
+      );
     }
     if (hasFlutterApi) {
       // Nothing yet.
@@ -291,7 +298,8 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
             indent.writeln('friend class ${friend.name};');
           }
         }
-        for (final Api api in root.apis) {
+        for (final Api api in root.apis
+            .where((Api api) => api is AstFlutterApi || api is AstHostApi)) {
           // TODO(gaaclarke): Find a way to be more precise with our
           // friendships.
           indent.writeln('friend class ${api.name};');
@@ -317,10 +325,9 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     CppOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(generatorOptions, root, indent, api);
     }
@@ -370,10 +377,9 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
     CppOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(generatorOptions, root, indent, api);
     }
@@ -778,6 +784,7 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
       final Iterable<_IndexedField> indexedFields = indexMap(
           getFieldsInSerializationOrder(classDefinition),
           (int index, NamedType field) => _IndexedField(index, field));
+
       final Iterable<_IndexedField> nullableFields = indexedFields
           .where((_IndexedField field) => field.field.type.isNullable);
       final Iterable<_IndexedField> nonNullableFields = indexedFields
@@ -823,10 +830,9 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
     CppOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(generatorOptions, root, indent, api);
     }
@@ -937,10 +943,9 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
     CppOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(generatorOptions, root, indent, api);
     }
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 52e2d0e68d95..b8601458e2dc 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -312,12 +312,11 @@ $resultAt != null
     DartOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     String Function(Method)? channelNameFunc,
     bool isMockHandler = false,
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
     String codecName = _standardMessageCodec;
     if (getCodecClasses(api, root).isNotEmpty) {
       codecName = _getCodecName(api);
@@ -488,10 +487,9 @@ $resultAt != null
     DartOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
     String codecName = _standardMessageCodec;
     if (getCodecClasses(api, root).isNotEmpty) {
       codecName = _getCodecName(api);
@@ -640,13 +638,11 @@ if (${_varNamePrefix}replyList == null) {
           relativeDartPath.replaceFirst(RegExp(r'^.*/lib/'), '');
       indent.writeln("import 'package:$dartOutputPackageName/$path';");
     }
-    for (final Api api in root.apis) {
-      if (api.location == ApiLocation.host && api.dartHostTestHandler != null) {
-        final Api mockApi = Api(
+    for (final AstHostApi api in root.apis.whereType<AstHostApi>()) {
+      if (api.dartHostTestHandler != null) {
+        final AstFlutterApi mockApi = AstFlutterApi(
           name: api.dartHostTestHandler!,
           methods: api.methods,
-          location: ApiLocation.flutter,
-          dartHostTestHandler: api.dartHostTestHandler,
           documentationComments: api.documentationComments,
         );
         writeFlutterApi(
@@ -696,10 +692,10 @@ if (${_varNamePrefix}replyList == null) {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi =
+        root.apis.any((Api api) => api.methods.isNotEmpty && api is AstHostApi);
+    final bool hasFlutterApi = root.apis
+        .any((Api api) => api.methods.isNotEmpty && api is AstFlutterApi);
 
     if (hasHostApi) {
       _writeCreateConnectionError(indent);
diff --git a/packages/pigeon/lib/generator.dart b/packages/pigeon/lib/generator.dart
index 1bd083078745..3711fd28dbe3 100644
--- a/packages/pigeon/lib/generator.dart
+++ b/packages/pigeon/lib/generator.dart
@@ -63,6 +63,24 @@ abstract class StructuredGenerator<T> extends Generator<T> {
       dartPackageName: dartPackageName,
     );
 
+    if (root.apis.any((Api api) => api is AstProxyApi)) {
+      writeInstanceManager(
+        generatorOptions,
+        root,
+        indent,
+        dartPackageName: dartPackageName,
+      );
+
+      writeInstanceManagerApi(
+        generatorOptions,
+        root,
+        indent,
+        dartPackageName: dartPackageName,
+      );
+
+      writeProxyApiBaseCodec(generatorOptions, root, indent);
+    }
+
     writeEnums(
       generatorOptions,
       root,
@@ -224,22 +242,31 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     required String dartPackageName,
   }) {
     for (final Api api in root.apis) {
-      if (api.location == ApiLocation.host) {
-        writeHostApi(
-          generatorOptions,
-          root,
-          indent,
-          api,
-          dartPackageName: dartPackageName,
-        );
-      } else if (api.location == ApiLocation.flutter) {
-        writeFlutterApi(
-          generatorOptions,
-          root,
-          indent,
-          api,
-          dartPackageName: dartPackageName,
-        );
+      switch (api) {
+        case AstHostApi():
+          writeHostApi(
+            generatorOptions,
+            root,
+            indent,
+            api,
+            dartPackageName: dartPackageName,
+          );
+        case AstFlutterApi():
+          writeFlutterApi(
+            generatorOptions,
+            root,
+            indent,
+            api,
+            dartPackageName: dartPackageName,
+          );
+        case AstProxyApi():
+          writeProxyApi(
+            generatorOptions,
+            root,
+            indent,
+            api,
+            dartPackageName: dartPackageName,
+          );
       }
     }
   }
@@ -249,7 +276,7 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     T generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   });
 
@@ -258,7 +285,49 @@ abstract class StructuredGenerator<T> extends Generator<T> {
     T generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   });
+
+  /// Writes the implementation of an `InstanceManager` to [indent].
+  void writeInstanceManager(
+    T generatorOptions,
+    Root root,
+    Indent indent, {
+    required String dartPackageName,
+  }) {}
+
+  /// Writes the implementation of the API for the `InstanceManager` to
+  /// [indent].
+  void writeInstanceManagerApi(
+    T generatorOptions,
+    Root root,
+    Indent indent, {
+    required String dartPackageName,
+  }) {}
+
+  /// Writes the base codec to be used by all ProxyApis.
+  ///
+  /// This codec should use `128` as the identifier for objects that exist in
+  /// an `InstanceManager`. The write implementation should convert an instance
+  /// to an identifier. The read implementation should covert the identifier
+  /// to an instance.
+  ///
+  /// This will serve as the default codec for all ProxyApis. If a ProxyApi
+  /// needs to create its own codec (it has methods/fields/constructor that use
+  /// a data class) it should extend this codec and not `StandardMessageCodec`.
+  void writeProxyApiBaseCodec(
+    T generatorOptions,
+    Root root,
+    Indent indent,
+  ) {}
+
+  /// Writes a single Proxy Api to [indent].
+  void writeProxyApi(
+    T generatorOptions,
+    Root root,
+    Indent indent,
+    AstProxyApi api, {
+    required String dartPackageName,
+  }) {}
 }
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index ba32f720a2a0..4fba3835620e 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -282,6 +282,24 @@ String getGeneratedCodeWarning() {
 /// String to be printed after `getGeneratedCodeWarning()'s warning`.
 const String seeAlsoWarning = 'See also: https://pub.dev/packages/pigeon';
 
+/// Prefix for utility classes generated for ProxyApis.
+///
+/// This lowers the chances of variable name collisions with user defined
+/// parameters.
+const String classNamePrefix = 'Pigeon_';
+
+/// Name for the generated InstanceManager for ProxyApis.
+///
+/// This lowers the chances of variable name collisions with user defined
+/// parameters.
+const String instanceManagerClassName = '${classNamePrefix}InstanceManager';
+
+/// Prefix for class member names not defined by the user.
+///
+/// This lowers the chances of variable name collisions with user defined
+/// parameters.
+const String classMemberNamePrefix = 'pigeon_';
+
 /// Collection of keys used in dictionaries across generators.
 class Keys {
   /// The key in the result hash for the 'result' value.
@@ -588,6 +606,88 @@ String? deducePackageName(String mainDartFile) {
   }
 }
 
+/// Recursively search for all the interfaces apis from a list of names of
+/// interfaces.
+///
+/// This method assumes that all interfaces names can be found in
+/// [allProxyApis]. Otherwise, throws an [ArgumentError].
+Set<AstProxyApi> recursiveFindAllInterfacesApis(
+  AstProxyApi api,
+  Iterable<AstProxyApi> allProxyApis,
+) {
+  final Set<AstProxyApi> interfacesApis = <AstProxyApi>{};
+
+  for (final AstProxyApi proxyApi in allProxyApis) {
+    if (api.interfacesNames.contains(proxyApi.name)) {
+      interfacesApis.add(proxyApi);
+    }
+  }
+
+  if (interfacesApis.length != api.interfacesNames.length) {
+    throw ArgumentError(
+      'Could not find a ProxyApi for every interface name: '
+      '${api.interfacesNames}, ${allProxyApis.map((Api api) => api.name)}',
+    );
+  }
+
+  for (final AstProxyApi proxyApi in Set<AstProxyApi>.from(interfacesApis)) {
+    interfacesApis.addAll(
+      recursiveFindAllInterfacesApis(proxyApi, allProxyApis),
+    );
+  }
+
+  return interfacesApis;
+}
+
+/// Creates a list of ProxyApis where each `extends` the ProxyApi that follows
+/// it.
+///
+/// Returns an empty list if [proxyApi] does not extend a ProxyApi.
+///
+/// This method assumes the super classes of each ProxyApi doesn't create a
+/// loop. Throws a [ArgumentError] if a loop is found.
+///
+/// This method also assumes that all super class names can be found in
+/// [allProxyApis]. Otherwise, throws an [ArgumentError].
+List<AstProxyApi> recursiveGetSuperClassApisChain(
+  AstProxyApi proxyApi,
+  Iterable<AstProxyApi> allProxyApis,
+) {
+  final List<AstProxyApi> proxyApis = <AstProxyApi>[];
+
+  String? currentProxyApiName = proxyApi.superClassName;
+  while (currentProxyApiName != null) {
+    if (proxyApis.length > allProxyApis.length) {
+      final Iterable<String> apiNames = proxyApis.map(
+        (AstProxyApi api) => api.name,
+      );
+      throw ArgumentError(
+        'Loop found when processing super classes for a ProxyApi: '
+        '${proxyApi.name},${apiNames.join(',')}',
+      );
+    }
+
+    AstProxyApi? nextProxyApi;
+    for (final AstProxyApi node in allProxyApis) {
+      if (currentProxyApiName == node.name) {
+        nextProxyApi = node;
+        proxyApis.add(node);
+      }
+    }
+
+    if (nextProxyApi == null) {
+      throw ArgumentError(
+        'Could not find a ProxyApi for every super class name: '
+        '$currentProxyApiName, ${allProxyApis.map((Api api) => api.name)}',
+      );
+    }
+
+    currentProxyApiName = nextProxyApi.superClassName;
+  }
+
+  return proxyApis;
+}
+
 /// Enum to specify api type when generating code.
 enum ApiType {
   /// Flutter api.
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 43b42c40e909..0758071e9435 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -400,7 +400,7 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     JavaOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
     /// Returns an argument name that can be used in a context where it is possible to collide
@@ -414,7 +414,6 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
       return '${_getArgumentName(count, argument)}Arg';
     }
 
-    assert(api.location == ApiLocation.flutter);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(indent, api, root);
     }
@@ -556,9 +555,9 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     required String dartPackageName,
   }) {
     if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
+        api is AstHostApi &&
             api.methods.any((Method it) => it.isAsynchronous) ||
-        api.location == ApiLocation.flutter)) {
+        api is AstFlutterApi)) {
       indent.newln();
       _writeResultInterfaces(indent);
     }
@@ -577,10 +576,9 @@ class JavaGenerator extends StructuredGenerator<JavaOptions> {
     JavaOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
     if (getCodecClasses(api, root).isNotEmpty) {
       _writeCodec(indent, api, root);
     }
@@ -979,10 +977,12 @@ protected static ArrayList<Object> wrapError(@NonNull Throwable exception) {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi = root.apis
+        .whereType<AstHostApi>()
+        .any((Api api) => api.methods.isNotEmpty);
+    final bool hasFlutterApi = root.apis
+        .whereType<AstFlutterApi>()
+        .any((Api api) => api.methods.isNotEmpty);
 
     indent.newln();
     _writeErrorClass(indent);
diff --git a/packages/pigeon/lib/kotlin_generator.dart b/packages/pigeon/lib/kotlin_generator.dart
index 88ffb487406e..78337cc2cb14 100644
--- a/packages/pigeon/lib/kotlin_generator.dart
+++ b/packages/pigeon/lib/kotlin_generator.dart
@@ -307,7 +307,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     required String dartPackageName,
   }) {
     if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
+        api is AstHostApi &&
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.newln();
     }
@@ -325,10 +325,9 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     KotlinOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
     final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
     if (isCustomCodec) {
       _writeCodec(indent, api, root);
@@ -448,11 +447,9 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     KotlinOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
-
     final String apiName = api.name;
 
     final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
@@ -742,10 +739,12 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi = root.apis
+        .whereType<AstHostApi>()
+        .any((Api api) => api.methods.isNotEmpty);
+    final bool hasFlutterApi = root.apis
+        .whereType<AstFlutterApi>()
+        .any((Api api) => api.methods.isNotEmpty);
 
     if (hasHostApi) {
       _writeWrapResult(indent);
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 903957d083c2..bc26495e650b 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -617,10 +617,9 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
     ObjcOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
     final String apiName = _className(generatorOptions.prefix, api.name);
 
     _writeCodecAndGetter(generatorOptions, root, indent, api);
@@ -649,10 +648,9 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
     ObjcOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
     final String apiName = _className(generatorOptions.prefix, api.name);
 
     _writeCodecAndGetter(generatorOptions, root, indent, api);
@@ -702,10 +700,12 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi = root.apis
+        .whereType<AstHostApi>()
+        .any((Api api) => api.methods.isNotEmpty);
+    final bool hasFlutterApi = root.apis
+        .whereType<AstFlutterApi>()
+        .any((Api api) => api.methods.isNotEmpty);
 
     if (hasHostApi) {
       _writeWrapError(indent);
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index e114af93caa4..2b3bda5f7ca1 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -39,9 +39,44 @@ class _Asynchronous {
   const _Asynchronous();
 }
 
+class _Attached {
+  const _Attached();
+}
+
+class _Static {
+  const _Static();
+}
+
 /// Metadata to annotate a Api method as asynchronous
 const Object async = _Asynchronous();
 
+/// Metadata to annotate the field of a ProxyApi as an Attached Field.
+///
+/// Attached fields provide a synchronous [AstProxyApi] instance as a field
+/// for another [AstProxyApi].
+///
+/// Attached fields:
+/// * Must be nonnull.
+/// * Must be a ProxyApi type.
+/// * Must be a ProxyApi that contains any fields.
+/// * Must be a ProxyApi that does not have a required Flutter method.
+///
+/// Example generated code:
+///
+/// ```dart
+/// class MyProxyApi {
+///   final MyOtherProxyApi myField = __pigeon_myField().
+/// }
+/// ```
+///
+/// The field provides access to the value synchronously, but the native
+/// instance is stored in the native `InstanceManager` asynchronously. Similar
+/// to how constructors are implemented.
+const Object attached = _Attached();
+
+/// Metadata to annotate an method or an Attached Field of a ProxyApi as static.
+const Object static = _Static();
+
 /// Metadata annotation used to configure how Pigeon will generate code.
 class ConfigurePigeon {
   /// Constructor for ConfigurePigeon.
@@ -88,6 +123,30 @@ class FlutterApi {
   const FlutterApi();
 }
 
+/// Metadata to annotate a Pigeon API that wraps a native class.
+///
+/// The abstract class with this annotation groups a collection of Dart↔host
+/// constructors, fields, methods and host↔Dart methods used to wrap a native
+/// class.
+///
+/// The generated Dart class acts as a proxy to a native type and
+/// maintains instances automatically with an `InstanceManager`. The generated
+/// host language class implements methods to interact with class instances
+/// or static methods.
+class ProxyApi {
+  /// Parametric constructor for [ProxyApi].
+  const ProxyApi({this.superClass});
+
+  /// The proxy api that is a super class to this one.
+  ///
+  /// This provides an alternative to calling `extends` on a class since this
+  /// requires calling the super class constructor.
+  ///
+  /// Note that using this instead of `extends` can cause unexpected conflicts
+  /// with inherited method names.
+  final Type? superClass;
+}
+
 /// Metadata to annotation methods to control the selector used for objc output.
 /// The number of components in the provided selector must match the number of
 /// arguments in the annotated method.
@@ -787,7 +846,16 @@ List<Error> _validateAst(Root root, String source) {
       }
     }
   }
+
   for (final Api api in root.apis) {
+    if (api is AstProxyApi) {
+      result.addAll(_validateProxyApi(
+        api,
+        source,
+        customClasses: customClasses.toSet(),
+        proxyApis: root.apis.whereType<AstProxyApi>().toSet(),
+      ));
+    }
     for (final Method method in api.methods) {
       for (final Parameter param in method.parameters) {
         if (param.type.baseName.isEmpty) {
@@ -809,7 +877,7 @@ List<Error> _validateAst(Root root, String source) {
             lineNumber: _calculateLineNumberNullable(source, param.offset),
           ));
         }
-        if (api.location == ApiLocation.flutter) {
+        if (api is AstFlutterApi) {
           if (!param.isPositional) {
             result.add(Error(
               message:
@@ -847,7 +915,7 @@ List<Error> _validateAst(Root root, String source) {
         }
       }
       if (method.taskQueueType != TaskQueueType.serial &&
-          api.location != ApiLocation.host) {
+          method.location == ApiLocation.flutter) {
         result.add(Error(
           message: 'Unsupported TaskQueue specification on ${method.name}',
           lineNumber: _calculateLineNumberNullable(source, method.offset),
@@ -859,6 +927,275 @@ List<Error> _validateAst(Root root, String source) {
   return result;
 }
 
+List<Error> _validateProxyApi(
+  AstProxyApi api,
+  String source, {
+  required Set<String> customClasses,
+  required Set<AstProxyApi> proxyApis,
+}) {
+  final List<Error> result = <Error>[];
+
+  bool isDataClass(NamedType type) =>
+      customClasses.contains(type.type.baseName);
+  bool isProxyApi(NamedType type) => proxyApis.any(
+        (AstProxyApi api) => api.name == type.type.baseName,
+      );
+  Error unsupportedDataClassError(NamedType type) {
+    return Error(
+      message: 'ProxyApis do not support data classes: ${type.type.baseName}.',
+      lineNumber: _calculateLineNumberNullable(source, type.offset),
+    );
+  }
+
+  // Validate super class is another ProxyApi
+  final String? superClassName = api.superClassName;
+  if (api.superClassName != null &&
+      !proxyApis.any((AstProxyApi api) => api.name == superClassName)) {
+    result.add(Error(
+      message:
+          'Super class of ${api.name} is not marked as a @ProxyApi: $superClassName',
+    ));
+  }
+
+  // Validate all interfaces are other ProxyApis
+  for (final String interfaceName in api.interfacesNames) {
+    if (!proxyApis.any((AstProxyApi api) => api.name == interfaceName)) {
+      result.add(Error(
+        message:
+            'Interface of ${api.name} is not marked as a @ProxyApi: $interfaceName',
+      ));
+    }
+  }
+
+  List<AstProxyApi>? superClassChain;
+  try {
+    superClassChain = recursiveGetSuperClassApisChain(api, proxyApis);
+  } catch (error) {
+    result.add(Error(message: error.toString()));
+  }
+
+  // Validate that the api does not inherit a non attached field from its super class.
+  if (superClassChain != null &&
+      superClassChain.isNotEmpty &&
+      superClassChain.first.unattachedFields.isNotEmpty) {
+    result.add(Error(
+      message:
+          'Non attached fields can not be inherited. Non attached field found for parent class ${api.unattachedFields.first.name}',
+      lineNumber: _calculateLineNumberNullable(
+        source,
+        api.unattachedFields.first.offset,
+      ),
+    ));
+  }
+
+  for (final AstProxyApi proxyApi in proxyApis) {
+    // Validate this api is not used as an attached field while either:
+    // 1. Having an unattached field.
+    // 2. Having a required Flutter method.
+    final bool hasUnattachedField = api.unattachedFields.isNotEmpty;
+    final bool hasRequiredFlutterMethod =
+        api.flutterMethods.any((Method method) => method.required);
+    if (hasUnattachedField || hasRequiredFlutterMethod) {
+      for (final Field field in proxyApi.attachedFields) {
+        if (field.type.baseName == api.name) {
+          if (hasUnattachedField) {
+            result.add(Error(
+              message:
+                  'ProxyApis with fields can not be used as attached fields: ${field.name}',
+              lineNumber: _calculateLineNumberNullable(
+                source,
+                field.offset,
+              ),
+            ));
+          }
+          if (hasRequiredFlutterMethod) {
+            result.add(Error(
+              message:
+                  'ProxyApis with required callback methods can not be used as attached fields: ${field.name}',
+              lineNumber: _calculateLineNumberNullable(
+                source,
+                field.offset,
+              ),
+            ));
+          }
+        }
+      }
+    }
+
+    // Validate this api isn't used as an interface and contains anything except
+    // Flutter methods.
+    final bool isValidInterfaceProxyApi = api.hostMethods.isEmpty &&
+        api.constructors.isEmpty &&
+        api.fields.isEmpty;
+    if (!isValidInterfaceProxyApi) {
+      for (final String interfaceName in proxyApi.interfacesNames) {
+        if (interfaceName == api.name) {
+          result.add(Error(
+            message:
+                'ProxyApis used as interfaces can only have callback methods: ${proxyApi.name}',
+          ));
+        }
+      }
+    }
+  }
+
+  // Validate constructor parameters
+  for (final Constructor constructor in api.constructors) {
+    for (final Parameter parameter in constructor.parameters) {
+      if (isDataClass(parameter)) {
+        result.add(unsupportedDataClassError(parameter));
+      }
+
+      if (api.fields.any((Field field) => field.name == parameter.name) ||
+          api.flutterMethods
+              .any((Method method) => method.name == parameter.name)) {
+        result.add(Error(
+          message:
+              'Parameter names must not share a name with a field or callback method in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      }
+
+      if (parameter.type.baseName.isEmpty) {
+        result.add(Error(
+          message:
+              'Parameters must specify their type in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      } else if (parameter.name.startsWith('__pigeon_')) {
+        result.add(Error(
+          message:
+              'Parameter name must not begin with "__pigeon_" in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      } else if (parameter.name == 'pigeonChannelCodec') {
+        result.add(Error(
+          message:
+              'Parameter name must not be "pigeonChannelCodec" in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      } else if (parameter.name.startsWith(classNamePrefix)) {
+        result.add(Error(
+          message:
+              'Parameter name must not begin with "$classNamePrefix" in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      } else if (parameter.name.startsWith(classMemberNamePrefix)) {
+        result.add(Error(
+          message:
+              'Parameter name must not begin with "$classMemberNamePrefix" in constructor "${constructor.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      }
+    }
+    if (constructor.swiftFunction.isNotEmpty) {
+      final RegExp signatureRegex =
+          RegExp('\\w+ *\\((\\w+:){${constructor.parameters.length}}\\)');
+      if (!signatureRegex.hasMatch(constructor.swiftFunction)) {
+        result.add(Error(
+          message:
+              'Invalid constructor signature, expected ${constructor.parameters.length} parameters.',
+          lineNumber: _calculateLineNumberNullable(source, constructor.offset),
+        ));
+      }
+    }
+  }
+
+  // Validate method parameters
+  for (final Method method in api.methods) {
+    for (final Parameter parameter in method.parameters) {
+      if (isDataClass(parameter)) {
+        result.add(unsupportedDataClassError(parameter));
+      }
+
+      if (parameter.name.startsWith(classNamePrefix)) {
+        result.add(Error(
+          message:
+              'Parameter name must not begin with "$classNamePrefix" in method "${method.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      } else if (parameter.name.startsWith(classMemberNamePrefix)) {
+        result.add(Error(
+          message:
+              'Parameter name must not begin with "$classMemberNamePrefix" in method "${method.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+        ));
+      }
+    }
+
+    if (method.location == ApiLocation.flutter && method.isStatic) {
+      result.add(Error(
+        message: 'Static callback methods are not supported: ${method.name}.',
+        lineNumber: _calculateLineNumberNullable(source, method.offset),
+      ));
+    }
+  }
+
+  // Validate fields
+  for (final Field field in api.fields) {
+    if (isDataClass(field)) {
+      result.add(unsupportedDataClassError(field));
+    } else if (field.isStatic) {
+      if (!isProxyApi(field)) {
+        result.add(Error(
+          message:
+              'Static fields are considered attached fields and must be a ProxyApi: ${field.type.baseName}.',
+          lineNumber: _calculateLineNumberNullable(source, field.offset),
+        ));
+      } else if (field.type.isNullable) {
+        result.add(Error(
+          message:
+              'Static fields are considered attached fields and must not be nullable: ${field.type.baseName}.',
+          lineNumber: _calculateLineNumberNullable(source, field.offset),
+        ));
+      }
+    } else if (field.isAttached) {
+      if (!isProxyApi(field)) {
+        result.add(Error(
+          message:
+              'Attached fields must be a ProxyApi: ${field.type.baseName}.',
+          lineNumber: _calculateLineNumberNullable(source, field.offset),
+        ));
+      }
+      if (field.type.isNullable) {
+        result.add(Error(
+          message:
+              'Attached fields must not be nullable: ${field.type.baseName}.',
+          lineNumber: _calculateLineNumberNullable(source, field.offset),
+        ));
+      }
+    }
+
+    if (field.name.startsWith('__pigeon_')) {
+      result.add(Error(
+        message:
+            'Field name must not begin with "__pigeon_" in API: "${api.name}"',
+        lineNumber: _calculateLineNumberNullable(source, field.offset),
+      ));
+    } else if (field.name == 'pigeonChannelCodec') {
+      result.add(Error(
+        message:
+            'Field name must not be "pigeonChannelCodec" in API: "${api.name}"',
+        lineNumber: _calculateLineNumberNullable(source, field.offset),
+      ));
+    } else if (field.name.startsWith(classNamePrefix)) {
+      result.add(Error(
+        message:
+            'Field name must not begin with "$classNamePrefix" in API: "${api.name}"',
+        lineNumber: _calculateLineNumberNullable(source, field.offset),
+      ));
+    } else if (field.name.startsWith(classMemberNamePrefix)) {
+      result.add(Error(
+        message:
+            'Field name must not begin with "$classMemberNamePrefix" in API: "${api.name}"',
+        lineNumber: _calculateLineNumberNullable(source, field.offset),
+      ));
+    }
+  }
+
+  return result;
+}
+
 class _FindInitializer extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
   dart_ast.Expression? initializer;
   @override
@@ -927,6 +1264,10 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
           !referencedEnums
               .map((Enum e) => e.name)
               .contains(element.key.baseName) &&
+          !_apis
+              .whereType<AstProxyApi>()
+              .map((AstProxyApi e) => e.name)
+              .contains(element.key.baseName) &&
           !validTypes.contains(element.key.baseName) &&
           !element.key.isVoid &&
           element.key.baseName != 'dynamic' &&
@@ -943,7 +1284,9 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     for (final Class classDefinition in referencedClasses) {
       final List<NamedType> fields = <NamedType>[];
       for (final NamedType field in classDefinition.fields) {
-        fields.add(field.copyWithType(_attachClassesAndEnums(field.type)));
+        fields.add(field.copyWithType(
+          _attachClassesEnumsAndProxyApis(field.type),
+        ));
       }
       classDefinition.fields = fields;
     }
@@ -952,10 +1295,31 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       for (final Method func in api.methods) {
         final List<Parameter> paramList = <Parameter>[];
         for (final Parameter param in func.parameters) {
-          paramList.add(param.copyWithType(_attachClassesAndEnums(param.type)));
+          paramList.add(param.copyWithType(
+            _attachClassesEnumsAndProxyApis(param.type),
+          ));
         }
         func.parameters = paramList;
-        func.returnType = _attachClassesAndEnums(func.returnType);
+        func.returnType = _attachClassesEnumsAndProxyApis(func.returnType);
+      }
+      if (api is AstProxyApi) {
+        for (final Constructor constructor in api.constructors) {
+          final List<Parameter> paramList = <Parameter>[];
+          for (final Parameter param in constructor.parameters) {
+            paramList.add(
+              param.copyWithType(_attachClassesEnumsAndProxyApis(param.type)),
+            );
+          }
+          constructor.parameters = paramList;
+        }
+
+        final List<Field> fieldList = <Field>[];
+        for (final Field field in api.fields) {
+          fieldList.add(field.copyWithType(
+            _attachClassesEnumsAndProxyApis(field.type),
+          ));
+        }
+        api.fields = fieldList;
       }
     }
 
@@ -968,15 +1332,21 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     );
   }
 
-  TypeDeclaration _attachClassesAndEnums(TypeDeclaration type) {
+  TypeDeclaration _attachClassesEnumsAndProxyApis(TypeDeclaration type) {
     final Enum? assocEnum = _enums.firstWhereOrNull(
         (Enum enumDefinition) => enumDefinition.name == type.baseName);
     final Class? assocClass = _classes.firstWhereOrNull(
         (Class classDefinition) => classDefinition.name == type.baseName);
+    final AstProxyApi? assocProxyApi =
+        _apis.whereType<AstProxyApi>().firstWhereOrNull(
+              (Api apiDefinition) => apiDefinition.name == type.baseName,
+            );
     if (assocClass != null) {
       return type.copyWithClass(assocClass);
     } else if (assocEnum != null) {
       return type.copyWithEnum(assocEnum);
+    } else if (assocProxyApi != null) {
+      return type.copyWithProxyApi(assocProxyApi);
     }
     return type;
   }
@@ -1003,6 +1373,8 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       return expression.value!;
     } else if (expression is dart_ast.BooleanLiteral) {
       return expression.value;
+    } else if (expression is dart_ast.SimpleIdentifier) {
+      return expression.name;
     } else if (expression is dart_ast.ListLiteral) {
       final List<dynamic> list = <dynamic>[];
       for (final dart_ast.CollectionElement element in expression.elements) {
@@ -1016,6 +1388,19 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
         }
       }
       return list;
+    } else if (expression is dart_ast.SetOrMapLiteral) {
+      final Set<dynamic> set = <dynamic>{};
+      for (final dart_ast.CollectionElement element in expression.elements) {
+        if (element is dart_ast.Expression) {
+          set.add(_expressionToMap(element));
+        } else {
+          _errors.add(Error(
+            message: 'expected Expression but found $element',
+            lineNumber: _calculateLineNumber(source, element.offset),
+          ));
+        }
+      }
+      return set;
     } else {
       _errors.add(Error(
         message:
@@ -1081,19 +1466,57 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
             }
           }
         }
-        _currentApi = Api(
+
+        _currentApi = AstHostApi(
           name: node.name.lexeme,
-          location: ApiLocation.host,
           methods: <Method>[],
           dartHostTestHandler: dartHostTestHandler,
           documentationComments:
               _documentationCommentsParser(node.documentationComment?.tokens),
         );
       } else if (_hasMetadata(node.metadata, 'FlutterApi')) {
-        _currentApi = Api(
+        _currentApi = AstFlutterApi(
+          name: node.name.lexeme,
+          methods: <Method>[],
+          documentationComments:
+              _documentationCommentsParser(node.documentationComment?.tokens),
+        );
+      } else if (_hasMetadata(node.metadata, 'ProxyApi')) {
+        final dart_ast.Annotation proxyApiAnnotation = node.metadata.firstWhere(
+          (dart_ast.Annotation element) => element.name.name == 'ProxyApi',
+        );
+
+        final Map<String, Object?> annotationMap = <String, Object?>{};
+        for (final dart_ast.Expression expression
+            in proxyApiAnnotation.arguments!.arguments) {
+          if (expression is dart_ast.NamedExpression) {
+            annotationMap[expression.name.label.name] =
+                _expressionToMap(expression.expression);
+          }
+        }
+
+        final String? superClassName = annotationMap['superClass'] as String?;
+        if (superClassName != null && node.extendsClause != null) {
+          _errors.add(
+            Error(
+              message:
+                  'ProxyApis should either set the super class in the annotation OR use extends: ("${node.name.lexeme}").',
+              lineNumber: _calculateLineNumber(source, node.offset),
+            ),
+          );
+        }
+
+        _currentApi = AstProxyApi(
           name: node.name.lexeme,
-          location: ApiLocation.flutter,
           methods: <Method>[],
+          constructors: <Constructor>[],
+          fields: <Field>[],
+          superClassName:
+              superClassName ?? node.extendsClause?.superclass.name2.lexeme,
+          interfacesNames: node.implementsClause?.interfaces
+                  .map<String>((dart_ast.NamedType type) => type.name2.lexeme)
+                  .toSet() ??
+              <String>{},
           documentationComments:
               _documentationCommentsParser(node.documentationComment?.tokens),
         );
@@ -1204,6 +1627,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     final List<Parameter> arguments =
         parameters.parameters.map(formalParameterToPigeonParameter).toList();
     final bool isAsynchronous = _hasMetadata(node.metadata, 'async');
+    final bool isStatic = _hasMetadata(node.metadata, 'static');
     final String objcSelector = _findMetadata(node.metadata, 'ObjCSelector')
             ?.arguments
             ?.arguments
@@ -1243,6 +1667,13 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
                   typeAnnotationsToTypeArguments(returnType.typeArguments),
               isNullable: returnType.question != null),
           parameters: arguments,
+          required: true,
+          isStatic: isStatic,
+          location: switch (_currentApi!) {
+            AstHostApi() => ApiLocation.host,
+            AstProxyApi() => ApiLocation.host,
+            AstFlutterApi() => ApiLocation.flutter,
+          },
           isAsynchronous: isAsynchronous,
           objcSelector: objcSelector,
           swiftFunction: swiftFunction,
@@ -1298,8 +1729,8 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
 
   @override
   Object? visitFieldDeclaration(dart_ast.FieldDeclaration node) {
+    final dart_ast.TypeAnnotation? type = node.fields.type;
     if (_currentClass != null) {
-      final dart_ast.TypeAnnotation? type = node.fields.type;
       if (node.isStatic) {
         _errors.add(Error(
             message:
@@ -1335,6 +1766,88 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
             message: 'Expected a named type but found "$node".',
             lineNumber: _calculateLineNumber(source, node.offset)));
       }
+    } else if (_currentApi is AstProxyApi) {
+      final bool isStatic = _hasMetadata(node.metadata, 'static');
+      if (type is dart_ast.GenericFunctionType) {
+        final List<Parameter> parameters = type.parameters.parameters
+            .map(formalParameterToPigeonParameter)
+            .toList();
+        final String swiftFunction =
+            _findMetadata(node.metadata, 'SwiftFunction')
+                    ?.arguments
+                    ?.arguments
+                    .first
+                    .asNullable<dart_ast.SimpleStringLiteral>()
+                    ?.value ??
+                '';
+        final dart_ast.ArgumentList? taskQueueArguments =
+            _findMetadata(node.metadata, 'TaskQueue')?.arguments;
+        final String? taskQueueTypeName = taskQueueArguments == null
+            ? null
+            : getFirstChildOfType<dart_ast.NamedExpression>(taskQueueArguments)
+                ?.expression
+                .asNullable<dart_ast.PrefixedIdentifier>()
+                ?.name;
+        final TaskQueueType taskQueueType =
+            _stringToEnum(TaskQueueType.values, taskQueueTypeName) ??
+                TaskQueueType.serial;
+
+        // Methods without named return types aren't supported.
+        final dart_ast.TypeAnnotation returnType = type.returnType!;
+        returnType as dart_ast.NamedType;
+
+        _currentApi!.methods.add(
+          Method(
+            name: node.fields.variables[0].name.lexeme,
+            returnType: TypeDeclaration(
+              baseName: _getNamedTypeQualifiedName(returnType),
+              typeArguments:
+                  typeAnnotationsToTypeArguments(returnType.typeArguments),
+              isNullable: returnType.question != null,
+            ),
+            location: ApiLocation.flutter,
+            required: type.question == null,
+            isStatic: isStatic,
+            parameters: parameters,
+            isAsynchronous: _hasMetadata(node.metadata, 'async'),
+            swiftFunction: swiftFunction,
+            offset: node.offset,
+            taskQueueType: taskQueueType,
+            documentationComments:
+                _documentationCommentsParser(node.documentationComment?.tokens),
+          ),
+        );
+      } else if (type is dart_ast.NamedType) {
+        final _FindInitializer findInitializerVisitor = _FindInitializer();
+        node.visitChildren(findInitializerVisitor);
+        if (findInitializerVisitor.initializer != null) {
+          _errors.add(Error(
+              message:
+                  'Initialization isn\'t supported for fields in ProxyApis ("$node"), just use nullable types with no initializer (example "int? x;").',
+              lineNumber: _calculateLineNumber(source, node.offset)));
+        } else {
+          final dart_ast.TypeArgumentList? typeArguments = type.typeArguments;
+          (_currentApi as AstProxyApi?)!.fields.add(
+                Field(
+                  type: TypeDeclaration(
+                    baseName: _getNamedTypeQualifiedName(type),
+                    isNullable: type.question != null,
+                    typeArguments: typeAnnotationsToTypeArguments(
+                      typeArguments,
+                    ),
+                  ),
+                  name: node.fields.variables[0].name.lexeme,
+                  isAttached:
+                      _hasMetadata(node.metadata, 'attached') || isStatic,
+                  isStatic: isStatic,
+                  offset: node.offset,
+                  documentationComments: _documentationCommentsParser(
+                    node.documentationComment?.tokens,
+                  ),
+                ),
+              );
+        }
+      }
     } else if (_currentApi != null) {
       _errors.add(Error(
           message: 'Fields aren\'t supported in Pigeon API classes ("$node").',
@@ -1346,7 +1859,30 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
 
   @override
   Object? visitConstructorDeclaration(dart_ast.ConstructorDeclaration node) {
-    if (_currentApi != null) {
+    if (_currentApi is AstProxyApi) {
+      final dart_ast.FormalParameterList parameters = node.parameters;
+      final List<Parameter> arguments =
+          parameters.parameters.map(formalParameterToPigeonParameter).toList();
+      final String swiftFunction = _findMetadata(node.metadata, 'SwiftFunction')
+              ?.arguments
+              ?.arguments
+              .first
+              .asNullable<dart_ast.SimpleStringLiteral>()
+              ?.value ??
+          '';
+
+      (_currentApi as AstProxyApi?)!.constructors.add(
+            Constructor(
+              name: node.name?.lexeme ?? '',
+              parameters: arguments,
+              swiftFunction: swiftFunction,
+              offset: node.offset,
+              documentationComments: _documentationCommentsParser(
+                node.documentationComment?.tokens,
+              ),
+            ),
+          );
+    } else if (_currentApi != null) {
       _errors.add(Error(
           message: 'Constructors aren\'t supported in API classes ("$node").',
           lineNumber: _calculateLineNumber(source, node.offset)));
diff --git a/packages/pigeon/lib/swift_generator.dart b/packages/pigeon/lib/swift_generator.dart
index ae869426e620..cd2b36880530 100644
--- a/packages/pigeon/lib/swift_generator.dart
+++ b/packages/pigeon/lib/swift_generator.dart
@@ -236,7 +236,7 @@ import FlutterMacOS
     required String dartPackageName,
   }) {
     if (root.apis.any((Api api) =>
-        api.location == ApiLocation.host &&
+        api is AstHostApi &&
         api.methods.any((Method it) => it.isAsynchronous))) {
       indent.newln();
     }
@@ -256,11 +256,9 @@ import FlutterMacOS
     SwiftOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstFlutterApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.flutter);
-
     /// Returns an argument name that can be used in a context where it is possible to collide.
     String getEnumSafeArgumentExpression(
         Root root, int count, NamedType argument) {
@@ -380,11 +378,9 @@ import FlutterMacOS
     SwiftOptions generatorOptions,
     Root root,
     Indent indent,
-    Api api, {
+    AstHostApi api, {
     required String dartPackageName,
   }) {
-    assert(api.location == ApiLocation.host);
-
     final String apiName = api.name;
 
     final bool isCustomCodec = getCodecClasses(api, root).isNotEmpty;
@@ -802,10 +798,12 @@ private func nilOrValue<T>(_ value: Any?) -> T? {
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.host);
-    final bool hasFlutterApi = root.apis.any((Api api) =>
-        api.methods.isNotEmpty && api.location == ApiLocation.flutter);
+    final bool hasHostApi = root.apis
+        .whereType<AstHostApi>()
+        .any((Api api) => api.methods.isNotEmpty);
+    final bool hasFlutterApi = root.apis
+        .whereType<AstFlutterApi>()
+        .any((Api api) => api.methods.isNotEmpty);
 
     if (hasHostApi) {
       _writeWrapResult(indent);
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index c820df9256f8..865a4ed151d7 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pigeon%22
-version: 16.0.0 # This must match the version in lib/generator_tools.dart
+version: 16.0.1 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=3.0.0 <4.0.0"
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index cbd290b42fa3..af7865815d3a 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -25,7 +25,7 @@ final Enum emptyEnum = Enum(
 void main() {
   test('gen one api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
           parameters: <Parameter>[
@@ -37,6 +37,8 @@ void main() {
                 ),
                 name: 'input')
           ],
+          required: true,
+          location: ApiLocation.host,
           returnType: TypeDeclaration(
             baseName: 'Output',
             isNullable: false,
@@ -101,7 +103,7 @@ void main() {
 
   test('naming follows style', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
           parameters: <Parameter>[
@@ -113,6 +115,7 @@ void main() {
                 ),
                 name: 'someInput')
           ],
+          location: ApiLocation.host,
           returnType: TypeDeclaration(
             baseName: 'Output',
             isNullable: false,
@@ -179,9 +182,10 @@ void main() {
 
   test('FlutterError fields are private with public accessors', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -230,9 +234,10 @@ void main() {
 
   test('Error field is private with public accessors', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -273,9 +278,10 @@ void main() {
 
   test('Spaces before {', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -350,9 +356,10 @@ void main() {
 
   test('include blocks follow style', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -423,9 +430,10 @@ void main() {
 
   test('namespaces follows style', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -478,9 +486,10 @@ void main() {
 
   test('data classes handle nullable fields', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -661,9 +670,10 @@ void main() {
 
   test('data classes handle non-nullable fields', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -804,9 +814,10 @@ void main() {
 
   test('host nullable return types map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'returnNullableBool',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'bool',
@@ -815,6 +826,7 @@ void main() {
         ),
         Method(
           name: 'returnNullableInt',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'int',
@@ -823,6 +835,7 @@ void main() {
         ),
         Method(
           name: 'returnNullableString',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'String',
@@ -831,6 +844,7 @@ void main() {
         ),
         Method(
           name: 'returnNullableList',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'List',
@@ -845,6 +859,7 @@ void main() {
         ),
         Method(
           name: 'returnNullableMap',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'Map',
@@ -863,6 +878,7 @@ void main() {
         ),
         Method(
           name: 'returnNullableDataClass',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'ReturnData',
@@ -921,9 +937,10 @@ void main() {
 
   test('host non-nullable return types map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'returnBool',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'bool',
@@ -932,6 +949,7 @@ void main() {
         ),
         Method(
           name: 'returnInt',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'int',
@@ -940,6 +958,7 @@ void main() {
         ),
         Method(
           name: 'returnString',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'String',
@@ -948,6 +967,7 @@ void main() {
         ),
         Method(
           name: 'returnList',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'List',
@@ -962,6 +982,7 @@ void main() {
         ),
         Method(
           name: 'returnMap',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration(
             baseName: 'Map',
@@ -980,6 +1001,7 @@ void main() {
         ),
         Method(
           name: 'returnDataClass',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'ReturnData',
@@ -1024,9 +1046,10 @@ void main() {
 
   test('host nullable arguments map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'aBool',
@@ -1179,9 +1202,10 @@ void main() {
 
   test('host non-nullable arguments map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'aBool',
@@ -1329,9 +1353,10 @@ void main() {
 
   test('flutter nullable arguments map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'aBool',
@@ -1488,9 +1513,10 @@ void main() {
 
   test('flutter non-nullable arguments map correctly', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'aBool',
@@ -1621,9 +1647,10 @@ void main() {
 
   test('host API argument extraction uses references', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'anArg',
@@ -1661,9 +1688,10 @@ void main() {
   test('enum argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Bar', methods: <Method>[
           Method(
               name: 'bar',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1705,13 +1733,13 @@ void main() {
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -1785,12 +1813,12 @@ void main() {
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1827,9 +1855,10 @@ void main() {
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1884,9 +1913,10 @@ void main() {
 
   test('Does not send unwrapped EncodableLists', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'aBool',
@@ -1966,15 +1996,17 @@ void main() {
 
   test('does not keep unowned references in async handlers', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'HostApi', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'HostApi', methods: <Method>[
         Method(
           name: 'noop',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration.voidDeclaration(),
           isAsynchronous: true,
         ),
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -1988,15 +2020,17 @@ void main() {
           isAsynchronous: true,
         ),
       ]),
-      Api(name: 'FlutterApi', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'FlutterApi', methods: <Method>[
         Method(
           name: 'noop',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[],
           returnType: const TypeDeclaration.voidDeclaration(),
           isAsynchronous: true,
         ),
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: const TypeDeclaration(
@@ -2038,12 +2072,12 @@ void main() {
   test('connection error contains channel name', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 83a6556c7fab..884dabf5f683 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -85,9 +85,10 @@ void main() {
 
   test('gen one host api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -137,9 +138,10 @@ void main() {
 
   test('host multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -170,9 +172,10 @@ void main() {
 
   test('flutter multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -305,9 +308,10 @@ void main() {
 
   test('flutterApi', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -358,9 +362,10 @@ void main() {
 
   test('host void', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -398,9 +403,10 @@ void main() {
 
   test('flutter void return', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -441,9 +447,10 @@ void main() {
 
   test('flutter void argument', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -477,9 +484,10 @@ void main() {
 
   test('flutter enum argument with enum class', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -531,9 +539,10 @@ void main() {
 
   test('primitive enum host', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -567,9 +576,10 @@ void main() {
 
   test('flutter non-nullable enum argument with enum class', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -620,9 +630,10 @@ void main() {
 
   test('host void argument', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -655,42 +666,40 @@ void main() {
 
   test('mock dart handler', () {
     final Root root = Root(apis: <Api>[
-      Api(
-          name: 'Api',
+      AstHostApi(name: 'Api', dartHostTestHandler: 'ApiMock', methods: <Method>[
+        Method(
+          name: 'doSomething',
           location: ApiLocation.host,
-          dartHostTestHandler: 'ApiMock',
-          methods: <Method>[
-            Method(
-              name: 'doSomething',
-              parameters: <Parameter>[
-                Parameter(
-                    type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      associatedClass: emptyClass,
-                    ),
-                    name: '')
-              ],
-              returnType: TypeDeclaration(
-                baseName: 'Output',
-                isNullable: false,
-                associatedClass: emptyClass,
-              ),
-            ),
-            Method(
-              name: 'voidReturner',
-              parameters: <Parameter>[
-                Parameter(
-                    type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      associatedClass: emptyClass,
-                    ),
-                    name: '')
-              ],
-              returnType: const TypeDeclaration.voidDeclaration(),
-            )
-          ])
+          parameters: <Parameter>[
+            Parameter(
+                type: TypeDeclaration(
+                  baseName: 'Input',
+                  isNullable: false,
+                  associatedClass: emptyClass,
+                ),
+                name: '')
+          ],
+          returnType: TypeDeclaration(
+            baseName: 'Output',
+            isNullable: false,
+            associatedClass: emptyClass,
+          ),
+        ),
+        Method(
+          name: 'voidReturner',
+          location: ApiLocation.host,
+          parameters: <Parameter>[
+            Parameter(
+                type: TypeDeclaration(
+                  baseName: 'Input',
+                  isNullable: false,
+                  associatedClass: emptyClass,
+                ),
+                name: '')
+          ],
+          returnType: const TypeDeclaration.voidDeclaration(),
+        )
+      ])
     ], classes: <Class>[
       Class(name: 'Input', fields: <NamedType>[
         NamedType(
@@ -748,9 +757,10 @@ void main() {
 
   test('gen one async Flutter Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -803,9 +813,10 @@ void main() {
 
   test('gen one async Flutter Api with void return', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -853,9 +864,10 @@ void main() {
 
   test('gen one async Host Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -906,9 +918,10 @@ void main() {
 
   test('async host void argument', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -1027,9 +1040,10 @@ void main() {
   test('host generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1061,9 +1075,10 @@ void main() {
   test('flutter generics argument with void return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1095,9 +1110,10 @@ void main() {
   test('host generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1129,9 +1145,10 @@ void main() {
   test('flutter generics argument non void return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1173,9 +1190,10 @@ void main() {
   test('return nullable host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1202,9 +1220,10 @@ void main() {
   test('return nullable collection host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: true,
@@ -1236,9 +1255,10 @@ void main() {
   test('return nullable async host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1266,9 +1286,10 @@ void main() {
   test('return nullable flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1295,9 +1316,10 @@ void main() {
   test('return nullable async flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1325,9 +1347,10 @@ void main() {
   test('platform error for return nil on nonnull', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: false,
@@ -1356,9 +1379,10 @@ void main() {
   test('nullable argument host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1388,9 +1412,10 @@ void main() {
   test('nullable argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1420,9 +1445,10 @@ void main() {
   test('named argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1502,13 +1528,13 @@ name: foobar
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -1577,12 +1603,12 @@ name: foobar
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1615,9 +1641,10 @@ name: foobar
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1668,13 +1695,13 @@ name: foobar
   test('host test code handles enums', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstHostApi(
             name: 'Api',
-            location: ApiLocation.host,
             dartHostTestHandler: 'ApiMock',
             methods: <Method>[
               Method(
                   name: 'doit',
+                  location: ApiLocation.host,
                   returnType: const TypeDeclaration.voidDeclaration(),
                   parameters: <Parameter>[
                     Parameter(
@@ -1721,9 +1748,10 @@ name: foobar
 
   test('connection error contains channel name', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'method',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType:
               const TypeDeclaration(baseName: 'Output', isNullable: false),
diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index 4570ac633aaa..8264496d3343 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -78,10 +78,10 @@ void main() {
   });
 
   test('get codec classes from argument type arguments', () {
-    final Api api =
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+    final AstFlutterApi api = AstFlutterApi(name: 'Api', methods: <Method>[
       Method(
         name: 'doSomething',
+        location: ApiLocation.flutter,
         parameters: <Parameter>[
           Parameter(
             type: TypeDeclaration(
@@ -123,10 +123,10 @@ void main() {
   });
 
   test('get codec classes from return value type arguments', () {
-    final Api api =
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+    final AstFlutterApi api = AstFlutterApi(name: 'Api', methods: <Method>[
       Method(
         name: 'doSomething',
+        location: ApiLocation.flutter,
         parameters: <Parameter>[
           Parameter(
             type: TypeDeclaration(
@@ -168,10 +168,10 @@ void main() {
   });
 
   test('get codec classes from all arguments', () {
-    final Api api =
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+    final AstFlutterApi api = AstFlutterApi(name: 'Api', methods: <Method>[
       Method(
         name: 'doSomething',
+        location: ApiLocation.flutter,
         parameters: <Parameter>[
           Parameter(
             type: TypeDeclaration(
@@ -216,9 +216,10 @@ void main() {
 
   test('getCodecClasses: nested type arguments', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'foo',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -272,12 +273,12 @@ void main() {
 
   test('getCodecClasses: with Object', () {
     final Root root = Root(apis: <Api>[
-      Api(
+      AstFlutterApi(
         name: 'Api1',
-        location: ApiLocation.flutter,
         methods: <Method>[
           Method(
             name: 'foo',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   name: 'x',
@@ -311,12 +312,12 @@ void main() {
 
   test('getCodecClasses: unique entries', () {
     final Root root = Root(apis: <Api>[
-      Api(
+      AstFlutterApi(
         name: 'Api1',
-        location: ApiLocation.flutter,
         methods: <Method>[
           Method(
             name: 'foo',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   name: 'x',
@@ -330,12 +331,12 @@ void main() {
           )
         ],
       ),
-      Api(
+      AstHostApi(
         name: 'Api2',
-        location: ApiLocation.host,
         methods: <Method>[
           Method(
             name: 'foo',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   name: 'x',
diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index cba2d702255c..97cbfe8b4d09 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -123,9 +123,10 @@ void main() {
 
   test('gen one host api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -265,9 +266,10 @@ void main() {
 
   test('gen one flutter api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -318,9 +320,10 @@ void main() {
 
   test('gen host void api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -359,9 +362,10 @@ void main() {
 
   test('gen flutter void return api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -403,9 +407,10 @@ void main() {
 
   test('gen host void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -440,9 +445,10 @@ void main() {
 
   test('gen flutter void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -578,9 +584,10 @@ void main() {
 
   test('gen one async Host Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -639,9 +646,10 @@ void main() {
 
   test('gen one async Flutter Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -745,9 +753,10 @@ void main() {
 
   test('primitive enum host', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -875,9 +884,10 @@ void main() {
   test('host generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -910,9 +920,10 @@ void main() {
   test('flutter generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -945,9 +956,10 @@ void main() {
   test('host generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -977,9 +989,10 @@ void main() {
   test('flutter generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1010,9 +1023,10 @@ void main() {
   test('flutter int return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType:
                   const TypeDeclaration(baseName: 'int', isNullable: false),
               parameters: <Parameter>[],
@@ -1041,9 +1055,10 @@ void main() {
 
   test('host multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1082,9 +1097,10 @@ void main() {
 
   test('if host argType is Object not cast', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'objectTest',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1110,9 +1126,10 @@ void main() {
 
   test('flutter multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1152,9 +1169,10 @@ void main() {
 
   test('flutter single args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'send',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1184,9 +1202,10 @@ void main() {
   test('return nullable host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1213,9 +1232,10 @@ void main() {
   test('return nullable host async', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1244,9 +1264,10 @@ void main() {
   test('nullable argument host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1277,9 +1298,10 @@ void main() {
   test('nullable argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1313,9 +1335,10 @@ void main() {
   test('background platform channel', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1415,13 +1438,13 @@ void main() {
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -1496,12 +1519,12 @@ void main() {
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1535,9 +1558,10 @@ void main() {
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1587,8 +1611,7 @@ void main() {
   });
 
   test('creates api error class for custom errors', () {
-    final Api api =
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[]);
+    final Api api = AstHostApi(name: 'Api', methods: <Method>[]);
     final Root root = Root(
       apis: <Api>[api],
       classes: <Class>[],
@@ -1610,12 +1633,12 @@ void main() {
   test('connection error contains channel name', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
diff --git a/packages/pigeon/test/kotlin_generator_test.dart b/packages/pigeon/test/kotlin_generator_test.dart
index f51c68b32bcc..e680e3ac66d2 100644
--- a/packages/pigeon/test/kotlin_generator_test.dart
+++ b/packages/pigeon/test/kotlin_generator_test.dart
@@ -140,9 +140,10 @@ void main() {
 
   test('primitive enum host', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -176,9 +177,10 @@ void main() {
 
   test('gen one host api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -405,9 +407,10 @@ void main() {
 
   test('gen one flutter api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -462,9 +465,10 @@ void main() {
 
   test('gen host void api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -505,9 +509,10 @@ void main() {
 
   test('gen flutter void return api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -550,9 +555,10 @@ void main() {
 
   test('gen host void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -590,9 +596,10 @@ void main() {
 
   test('gen flutter void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -732,9 +739,10 @@ void main() {
 
   test('gen one async Host Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -790,9 +798,10 @@ void main() {
 
   test('gen one async Flutter Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -979,9 +988,10 @@ void main() {
   test('host generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1015,9 +1025,10 @@ void main() {
   test('flutter generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1051,9 +1062,10 @@ void main() {
   test('host generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1084,9 +1096,10 @@ void main() {
   test('flutter generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1116,9 +1129,10 @@ void main() {
 
   test('host multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1159,9 +1173,10 @@ void main() {
 
   test('flutter multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1203,9 +1218,10 @@ void main() {
   test('return nullable host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1232,9 +1248,10 @@ void main() {
   test('return nullable host async', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1262,9 +1279,10 @@ void main() {
   test('nullable argument host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1298,9 +1316,10 @@ void main() {
   test('nullable argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1333,9 +1352,10 @@ void main() {
 
   test('nonnull fields', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
               type: TypeDeclaration(
@@ -1389,13 +1409,13 @@ void main() {
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -1470,12 +1490,12 @@ void main() {
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1509,9 +1529,10 @@ void main() {
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1563,10 +1584,11 @@ void main() {
   test('creates api error class for custom errors', () {
     final Method method = Method(
         name: 'doSomething',
+        location: ApiLocation.host,
         returnType: const TypeDeclaration.voidDeclaration(),
         parameters: <Parameter>[]);
-    final Api api = Api(
-        name: 'SomeApi', location: ApiLocation.host, methods: <Method>[method]);
+    final AstHostApi api =
+        AstHostApi(name: 'SomeApi', methods: <Method>[method]);
     final Root root = Root(
       apis: <Api>[api],
       classes: <Class>[],
@@ -1593,12 +1615,12 @@ void main() {
   test('connection error contains channel name', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1639,12 +1661,12 @@ void main() {
   test('gen host uses default error class', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstHostApi(
           name: 'Api',
-          location: ApiLocation.host,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1678,12 +1700,12 @@ void main() {
   test('gen flutter uses default error class', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1717,12 +1739,12 @@ void main() {
   test('gen host uses error class', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstHostApi(
           name: 'Api',
-          location: ApiLocation.host,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1759,12 +1781,12 @@ void main() {
   test('gen flutter uses error class', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
diff --git a/packages/pigeon/test/objc_generator_test.dart b/packages/pigeon/test/objc_generator_test.dart
index f77f186ac8df..267747e1e913 100644
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@@ -188,9 +188,10 @@ void main() {
 
   test('primitive enum host', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -251,9 +252,10 @@ void main() {
 
   test('validate nullable primitive enum', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -328,9 +330,10 @@ void main() {
 
   test('gen one api header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -383,9 +386,10 @@ void main() {
 
   test('gen one api source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -656,9 +660,10 @@ void main() {
 
   test('prefix nested class header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -711,9 +716,10 @@ void main() {
 
   test('prefix nested class source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -766,9 +772,10 @@ void main() {
 
   test('gen flutter api header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -821,9 +828,10 @@ void main() {
 
   test('gen flutter api source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -872,9 +880,10 @@ void main() {
 
   test('gen host void header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -913,9 +922,10 @@ void main() {
 
   test('gen host void source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -956,9 +966,10 @@ void main() {
 
   test('gen flutter void return header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -997,9 +1008,10 @@ void main() {
 
   test('gen flutter void return source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -1039,9 +1051,10 @@ void main() {
 
   test('gen host void arg header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1076,9 +1089,10 @@ void main() {
 
   test('gen host void arg source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1113,9 +1127,10 @@ void main() {
 
   test('gen flutter void arg header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1153,9 +1168,10 @@ void main() {
 
   test('gen flutter void arg source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.flutter,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1281,9 +1297,10 @@ void main() {
 
   test('gen map argument with object', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doit',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -1317,9 +1334,10 @@ void main() {
 
   test('async void (input) HostApi header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -1367,9 +1385,10 @@ void main() {
 
   test('async output(input) HostApi header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -1421,9 +1440,10 @@ void main() {
 
   test('async output(void) HostApi header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1462,9 +1482,10 @@ void main() {
 
   test('async void (void) HostApi header', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: const TypeDeclaration.voidDeclaration(),
             isAsynchronous: true)
@@ -1493,9 +1514,10 @@ void main() {
 
   test('async output(input) HostApi source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -1547,9 +1569,10 @@ void main() {
 
   test('async void (input) HostApi source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                   type: TypeDeclaration(
@@ -1597,9 +1620,10 @@ void main() {
 
   test('async void (void) HostApi source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: const TypeDeclaration.voidDeclaration(),
             isAsynchronous: true)
@@ -1628,9 +1652,10 @@ void main() {
 
   test('async output(void) HostApi source', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
             name: 'doSomething',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             returnType: TypeDeclaration(
               baseName: 'Output',
@@ -1755,9 +1780,10 @@ void main() {
   test('host generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1818,9 +1844,10 @@ void main() {
   test('flutter generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1878,9 +1905,10 @@ void main() {
   test('host nested generic argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1926,9 +1954,10 @@ void main() {
   test('host generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -1983,9 +2012,10 @@ void main() {
   test('flutter generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -2040,9 +2070,10 @@ void main() {
 
   test('host multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -2110,9 +2141,10 @@ void main() {
 
   test('host multiple args async', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -2180,9 +2212,10 @@ void main() {
 
   test('flutter multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -2245,25 +2278,48 @@ void main() {
 
   Root getDivideRoot(ApiLocation location) => Root(
         apis: <Api>[
-          Api(name: 'Api', location: location, methods: <Method>[
-            Method(
-                name: 'divide',
-                objcSelector: 'divideValue:by:',
-                parameters: <Parameter>[
-                  Parameter(
-                    type: const TypeDeclaration(
-                        baseName: 'int', isNullable: false),
-                    name: 'x',
-                  ),
-                  Parameter(
-                    type: const TypeDeclaration(
-                        baseName: 'int', isNullable: false),
-                    name: 'y',
-                  ),
-                ],
-                returnType: const TypeDeclaration(
-                    baseName: 'double', isNullable: false))
-          ])
+          switch (location) {
+            ApiLocation.host => AstHostApi(name: 'Api', methods: <Method>[
+                Method(
+                    name: 'divide',
+                    location: location,
+                    objcSelector: 'divideValue:by:',
+                    parameters: <Parameter>[
+                      Parameter(
+                        type: const TypeDeclaration(
+                            baseName: 'int', isNullable: false),
+                        name: 'x',
+                      ),
+                      Parameter(
+                        type: const TypeDeclaration(
+                            baseName: 'int', isNullable: false),
+                        name: 'y',
+                      ),
+                    ],
+                    returnType: const TypeDeclaration(
+                        baseName: 'double', isNullable: false))
+              ]),
+            ApiLocation.flutter => AstFlutterApi(name: 'Api', methods: <Method>[
+                Method(
+                    name: 'divide',
+                    location: location,
+                    objcSelector: 'divideValue:by:',
+                    parameters: <Parameter>[
+                      Parameter(
+                        type: const TypeDeclaration(
+                            baseName: 'int', isNullable: false),
+                        name: 'x',
+                      ),
+                      Parameter(
+                        type: const TypeDeclaration(
+                            baseName: 'int', isNullable: false),
+                        name: 'y',
+                      ),
+                    ],
+                    returnType: const TypeDeclaration(
+                        baseName: 'double', isNullable: false))
+              ]),
+          }
         ],
         classes: <Class>[],
         enums: <Enum>[],
@@ -2378,9 +2434,10 @@ void main() {
   test('return nullable flutter header', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -2414,9 +2471,10 @@ void main() {
   test('return nullable flutter source', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -2447,9 +2505,10 @@ void main() {
   test('return nullable host header', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -2480,9 +2539,10 @@ void main() {
   test('nullable argument host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -2537,9 +2597,10 @@ void main() {
   test('nullable argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -2593,9 +2654,10 @@ void main() {
   test('background platform channel', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -2644,13 +2706,13 @@ void main() {
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -2725,12 +2787,12 @@ void main() {
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -2767,9 +2829,10 @@ void main() {
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -2825,12 +2888,12 @@ void main() {
   test('connection error contains channel name', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 5d60f92bf69d..7998733664ab 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -313,7 +313,7 @@ abstract class AFlutterApi {
     expect(results.errors.length, equals(0));
     expect(results.root.apis.length, equals(1));
     expect(results.root.apis[0].name, equals('AFlutterApi'));
-    expect(results.root.apis[0].location, equals(ApiLocation.flutter));
+    expect(results.root.apis[0], isA<AstFlutterApi>());
   });
 
   test('void host api', () {
@@ -370,8 +370,10 @@ abstract class ApiWithMockDartClass {
     final ParseResults results = parseSource(code);
     expect(results.errors.length, equals(0));
     expect(results.root.apis.length, equals(1));
-    expect(results.root.apis[0].dartHostTestHandler,
-        equals('ApiWithMockDartClassMock'));
+    expect(
+      (results.root.apis[0] as AstHostApi).dartHostTestHandler,
+      equals('ApiWithMockDartClassMock'),
+    );
   });
 
   test('only visible from nesting', () {
diff --git a/packages/pigeon/test/swift_generator_test.dart b/packages/pigeon/test/swift_generator_test.dart
index 4c07b784eb74..e43dc8efed62 100644
--- a/packages/pigeon/test/swift_generator_test.dart
+++ b/packages/pigeon/test/swift_generator_test.dart
@@ -84,9 +84,10 @@ void main() {
 
   test('primitive enum host', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Bar', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Bar', methods: <Method>[
         Method(
             name: 'bar',
+            location: ApiLocation.host,
             returnType: const TypeDeclaration.voidDeclaration(),
             parameters: <Parameter>[
               Parameter(
@@ -120,9 +121,10 @@ void main() {
 
   test('gen one host api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -248,9 +250,10 @@ void main() {
 
   test('gen one flutter api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -302,9 +305,10 @@ void main() {
 
   test('gen host void api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -343,9 +347,10 @@ void main() {
 
   test('gen flutter void return api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -385,9 +390,10 @@ void main() {
 
   test('gen host void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -423,9 +429,10 @@ void main() {
 
   test('gen flutter void argument api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[],
           returnType: TypeDeclaration(
             baseName: 'Output',
@@ -560,9 +567,10 @@ void main() {
 
   test('gen one async Host Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -615,9 +623,10 @@ void main() {
 
   test('gen one async Flutter Api', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -798,9 +807,10 @@ void main() {
   test('host generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -833,9 +843,10 @@ void main() {
   test('flutter generics argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -868,9 +879,10 @@ void main() {
   test('host generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -901,9 +913,10 @@ void main() {
   test('flutter generics return', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration(
                   baseName: 'List',
                   isNullable: false,
@@ -936,9 +949,10 @@ void main() {
 
   test('host multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -979,9 +993,10 @@ void main() {
 
   test('flutter multiple args', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'add',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 name: 'x',
@@ -1023,9 +1038,10 @@ void main() {
   test('return nullable host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1052,9 +1068,10 @@ void main() {
   test('return nullable host async', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration(
                 baseName: 'int',
                 isNullable: true,
@@ -1085,9 +1102,10 @@ void main() {
   test('nullable argument host', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.host,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1121,9 +1139,10 @@ void main() {
   test('nullable argument flutter', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        AstFlutterApi(name: 'Api', methods: <Method>[
           Method(
               name: 'doit',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1156,9 +1175,10 @@ void main() {
 
   test('nonnull fields', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+      AstHostApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.host,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1210,13 +1230,13 @@ void main() {
 
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'api',
-          location: ApiLocation.flutter,
           documentationComments: <String>[comments[count++]],
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               documentationComments: <String>[comments[count++]],
               parameters: <Parameter>[
@@ -1287,12 +1307,12 @@ void main() {
   test("doesn't create codecs if no custom datatypes", () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(
@@ -1325,9 +1345,10 @@ void main() {
 
   test('creates custom codecs if custom datatypes present', () {
     final Root root = Root(apis: <Api>[
-      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+      AstFlutterApi(name: 'Api', methods: <Method>[
         Method(
           name: 'doSomething',
+          location: ApiLocation.flutter,
           parameters: <Parameter>[
             Parameter(
                 type: TypeDeclaration(
@@ -1379,9 +1400,10 @@ void main() {
   test('swift function signature', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
             name: 'set',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                 type: const TypeDeclaration(
@@ -1422,9 +1444,10 @@ void main() {
   test('swift function signature with same name argument', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
             name: 'set',
+            location: ApiLocation.host,
             parameters: <Parameter>[
               Parameter(
                 type: const TypeDeclaration(
@@ -1458,9 +1481,10 @@ void main() {
   test('swift function signature with no arguments', () {
     final Root root = Root(
       apis: <Api>[
-        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+        AstHostApi(name: 'Api', methods: <Method>[
           Method(
             name: 'clear',
+            location: ApiLocation.host,
             parameters: <Parameter>[],
             swiftFunction: 'removeAll()',
             returnType: const TypeDeclaration.voidDeclaration(),
@@ -1486,12 +1510,12 @@ void main() {
   test('connection error contains channel name', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstFlutterApi(
           name: 'Api',
-          location: ApiLocation.flutter,
           methods: <Method>[
             Method(
               name: 'method',
+              location: ApiLocation.flutter,
               returnType: const TypeDeclaration.voidDeclaration(),
               parameters: <Parameter>[
                 Parameter(

From abc026ad21bad0a91b532a786aba133f0ea293a6 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 10 Jan 2024 17:21:38 -0500
Subject: [PATCH 02/32] constructor extend method and make required default to
 true

---
 packages/pigeon/lib/ast.dart        | 38 +++++++++--------------------
 packages/pigeon/lib/pigeon_lib.dart |  1 -
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 7b0e32511fae..db663f18bf38 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -30,7 +30,7 @@ class Method extends Node {
     required this.returnType,
     required this.parameters,
     required this.location,
-    this.required = false,
+    this.required = true,
     this.isAsynchronous = false,
     this.isStatic = false,
     this.offset,
@@ -184,34 +184,18 @@ class AstProxyApi extends Api {
 }
 
 /// Represents a constructor for an API.
-class Constructor extends Node {
+class Constructor extends Method {
   /// Parametric constructor for [Constructor].
   Constructor({
-    required this.name,
-    required this.parameters,
-    this.offset,
-    this.swiftFunction = '',
-    this.documentationComments = const <String>[],
-  });
-
-  /// The name of the method.
-  String name;
-
-  /// The parameters passed into the [Constructor].
-  List<Parameter> parameters;
-
-  /// The offset in the source file where the field appears.
-  int? offset;
-
-  /// An override for the generated swift function signature (ex. "divideNumber(_:by:)").
-  String swiftFunction;
-
-  /// List of documentation comments, separated by line.
-  ///
-  /// Lines should not include the comment marker itself, but should include any
-  /// leading whitespace, so that any indentation in the original comment is preserved.
-  /// For example: [" List of documentation comments, separated by line.", ...]
-  List<String> documentationComments;
+    required super.name,
+    required super.parameters,
+    super.offset,
+    super.swiftFunction = '',
+    super.documentationComments = const <String>[],
+  }) : super(
+          returnType: const TypeDeclaration.voidDeclaration(),
+          location: ApiLocation.host,
+        );
 
   @override
   String toString() {
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 2b3bda5f7ca1..ca268c809eab 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -1667,7 +1667,6 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
                   typeAnnotationsToTypeArguments(returnType.typeArguments),
               isNullable: returnType.question != null),
           parameters: arguments,
-          required: true,
           isStatic: isStatic,
           location: switch (_currentApi!) {
             AstHostApi() => ApiLocation.host,

From 0c69e1dc171a03343b5ced995be5faa305dbcfd3 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 10 Jan 2024 17:50:08 -0500
Subject: [PATCH 03/32] use helper method

---
 packages/pigeon/lib/pigeon_lib.dart | 167 ++++++++++++++--------------
 1 file changed, 86 insertions(+), 81 deletions(-)

diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index ca268c809eab..9791622b8a3c 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -1766,87 +1766,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
             lineNumber: _calculateLineNumber(source, node.offset)));
       }
     } else if (_currentApi is AstProxyApi) {
-      final bool isStatic = _hasMetadata(node.metadata, 'static');
-      if (type is dart_ast.GenericFunctionType) {
-        final List<Parameter> parameters = type.parameters.parameters
-            .map(formalParameterToPigeonParameter)
-            .toList();
-        final String swiftFunction =
-            _findMetadata(node.metadata, 'SwiftFunction')
-                    ?.arguments
-                    ?.arguments
-                    .first
-                    .asNullable<dart_ast.SimpleStringLiteral>()
-                    ?.value ??
-                '';
-        final dart_ast.ArgumentList? taskQueueArguments =
-            _findMetadata(node.metadata, 'TaskQueue')?.arguments;
-        final String? taskQueueTypeName = taskQueueArguments == null
-            ? null
-            : getFirstChildOfType<dart_ast.NamedExpression>(taskQueueArguments)
-                ?.expression
-                .asNullable<dart_ast.PrefixedIdentifier>()
-                ?.name;
-        final TaskQueueType taskQueueType =
-            _stringToEnum(TaskQueueType.values, taskQueueTypeName) ??
-                TaskQueueType.serial;
-
-        // Methods without named return types aren't supported.
-        final dart_ast.TypeAnnotation returnType = type.returnType!;
-        returnType as dart_ast.NamedType;
-
-        _currentApi!.methods.add(
-          Method(
-            name: node.fields.variables[0].name.lexeme,
-            returnType: TypeDeclaration(
-              baseName: _getNamedTypeQualifiedName(returnType),
-              typeArguments:
-                  typeAnnotationsToTypeArguments(returnType.typeArguments),
-              isNullable: returnType.question != null,
-            ),
-            location: ApiLocation.flutter,
-            required: type.question == null,
-            isStatic: isStatic,
-            parameters: parameters,
-            isAsynchronous: _hasMetadata(node.metadata, 'async'),
-            swiftFunction: swiftFunction,
-            offset: node.offset,
-            taskQueueType: taskQueueType,
-            documentationComments:
-                _documentationCommentsParser(node.documentationComment?.tokens),
-          ),
-        );
-      } else if (type is dart_ast.NamedType) {
-        final _FindInitializer findInitializerVisitor = _FindInitializer();
-        node.visitChildren(findInitializerVisitor);
-        if (findInitializerVisitor.initializer != null) {
-          _errors.add(Error(
-              message:
-                  'Initialization isn\'t supported for fields in ProxyApis ("$node"), just use nullable types with no initializer (example "int? x;").',
-              lineNumber: _calculateLineNumber(source, node.offset)));
-        } else {
-          final dart_ast.TypeArgumentList? typeArguments = type.typeArguments;
-          (_currentApi as AstProxyApi?)!.fields.add(
-                Field(
-                  type: TypeDeclaration(
-                    baseName: _getNamedTypeQualifiedName(type),
-                    isNullable: type.question != null,
-                    typeArguments: typeAnnotationsToTypeArguments(
-                      typeArguments,
-                    ),
-                  ),
-                  name: node.fields.variables[0].name.lexeme,
-                  isAttached:
-                      _hasMetadata(node.metadata, 'attached') || isStatic,
-                  isStatic: isStatic,
-                  offset: node.offset,
-                  documentationComments: _documentationCommentsParser(
-                    node.documentationComment?.tokens,
-                  ),
-                ),
-              );
-        }
-      }
+      _addProxyApiField(type, node);
     } else if (_currentApi != null) {
       _errors.add(Error(
           message: 'Fields aren\'t supported in Pigeon API classes ("$node").',
@@ -1919,6 +1839,91 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     }
     return node.name2.lexeme;
   }
+
+  void _addProxyApiField(
+    dart_ast.TypeAnnotation? type,
+    dart_ast.FieldDeclaration node,
+  ) {
+    final bool isStatic = _hasMetadata(node.metadata, 'static');
+    if (type is dart_ast.GenericFunctionType) {
+      final List<Parameter> parameters = type.parameters.parameters
+          .map(formalParameterToPigeonParameter)
+          .toList();
+      final String swiftFunction = _findMetadata(node.metadata, 'SwiftFunction')
+              ?.arguments
+              ?.arguments
+              .first
+              .asNullable<dart_ast.SimpleStringLiteral>()
+              ?.value ??
+          '';
+      final dart_ast.ArgumentList? taskQueueArguments =
+          _findMetadata(node.metadata, 'TaskQueue')?.arguments;
+      final String? taskQueueTypeName = taskQueueArguments == null
+          ? null
+          : getFirstChildOfType<dart_ast.NamedExpression>(taskQueueArguments)
+              ?.expression
+              .asNullable<dart_ast.PrefixedIdentifier>()
+              ?.name;
+      final TaskQueueType taskQueueType =
+          _stringToEnum(TaskQueueType.values, taskQueueTypeName) ??
+              TaskQueueType.serial;
+
+      // Methods without named return types aren't supported.
+      final dart_ast.TypeAnnotation returnType = type.returnType!;
+      returnType as dart_ast.NamedType;
+
+      _currentApi!.methods.add(
+        Method(
+          name: node.fields.variables[0].name.lexeme,
+          returnType: TypeDeclaration(
+            baseName: _getNamedTypeQualifiedName(returnType),
+            typeArguments:
+                typeAnnotationsToTypeArguments(returnType.typeArguments),
+            isNullable: returnType.question != null,
+          ),
+          location: ApiLocation.flutter,
+          required: type.question == null,
+          isStatic: isStatic,
+          parameters: parameters,
+          isAsynchronous: _hasMetadata(node.metadata, 'async'),
+          swiftFunction: swiftFunction,
+          offset: node.offset,
+          taskQueueType: taskQueueType,
+          documentationComments:
+              _documentationCommentsParser(node.documentationComment?.tokens),
+        ),
+      );
+    } else if (type is dart_ast.NamedType) {
+      final _FindInitializer findInitializerVisitor = _FindInitializer();
+      node.visitChildren(findInitializerVisitor);
+      if (findInitializerVisitor.initializer != null) {
+        _errors.add(Error(
+            message:
+                'Initialization isn\'t supported for fields in ProxyApis ("$node"), just use nullable types with no initializer (example "int? x;").',
+            lineNumber: _calculateLineNumber(source, node.offset)));
+      } else {
+        final dart_ast.TypeArgumentList? typeArguments = type.typeArguments;
+        (_currentApi as AstProxyApi?)!.fields.add(
+              Field(
+                type: TypeDeclaration(
+                  baseName: _getNamedTypeQualifiedName(type),
+                  isNullable: type.question != null,
+                  typeArguments: typeAnnotationsToTypeArguments(
+                    typeArguments,
+                  ),
+                ),
+                name: node.fields.variables[0].name.lexeme,
+                isAttached: _hasMetadata(node.metadata, 'attached') || isStatic,
+                isStatic: isStatic,
+                offset: node.offset,
+                documentationComments: _documentationCommentsParser(
+                  node.documentationComment?.tokens,
+                ),
+              ),
+            );
+      }
+    }
+  }
 }
 
 int? _calculateLineNumberNullable(String contents, int? offset) {

From eb14522bf8252e1e82b2cb95b94bb116ef70b31a Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 00:20:20 -0500
Subject: [PATCH 04/32] fix some validation and add tests

---
 packages/pigeon/lib/generator_tools.dart  |  13 ++
 packages/pigeon/lib/pigeon_lib.dart       |  31 ++--
 packages/pigeon/test/pigeon_lib_test.dart | 212 ++++++++++++++++++++++
 3 files changed, 240 insertions(+), 16 deletions(-)

diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 4fba3835620e..7fa2f967cf9a 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -437,6 +437,19 @@ Map<TypeDeclaration, List<int>> getReferencedTypes(
       }
       references.addMany(_getTypeArguments(method.returnType), method.offset);
     }
+    if (api is AstProxyApi) {
+      for (final Constructor constructor in api.constructors) {
+        for (final NamedType parameter in constructor.parameters) {
+          references.addMany(
+            _getTypeArguments(parameter.type),
+            parameter.offset,
+          );
+        }
+      }
+      for (final Field field in api.fields) {
+        references.addMany(_getTypeArguments(field.type), field.offset);
+      }
+    }
   }
 
   final Set<String> referencedTypeNames =
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 9791622b8a3c..1e69a4818415 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -974,34 +974,34 @@ List<Error> _validateProxyApi(
     result.add(Error(message: error.toString()));
   }
 
-  // Validate that the api does not inherit a non attached field from its super class.
-  if (superClassChain != null &&
-      superClassChain.isNotEmpty &&
-      superClassChain.first.unattachedFields.isNotEmpty) {
+  // Validate that the api does not inherit an unattached field from its super class.
+  final AstProxyApi? directSuperClass = superClassChain?.firstOrNull;
+  if (directSuperClass != null &&
+      directSuperClass.unattachedFields.isNotEmpty) {
     result.add(Error(
       message:
-          'Non attached fields can not be inherited. Non attached field found for parent class ${api.unattachedFields.first.name}',
+          'Unattached fields can not be inherited. Unattached field found for parent class: ${directSuperClass.unattachedFields.first.name}',
       lineNumber: _calculateLineNumberNullable(
         source,
-        api.unattachedFields.first.offset,
+        directSuperClass.unattachedFields.first.offset,
       ),
     ));
   }
 
+  final bool hasUnattachedField = api.unattachedFields.isNotEmpty;
+  final bool hasRequiredFlutterMethod =
+      api.flutterMethods.any((Method method) => method.required);
   for (final AstProxyApi proxyApi in proxyApis) {
     // Validate this api is not used as an attached field while either:
     // 1. Having an unattached field.
     // 2. Having a required Flutter method.
-    final bool hasUnattachedField = api.unattachedFields.isNotEmpty;
-    final bool hasRequiredFlutterMethod =
-        api.flutterMethods.any((Method method) => method.required);
     if (hasUnattachedField || hasRequiredFlutterMethod) {
       for (final Field field in proxyApi.attachedFields) {
         if (field.type.baseName == api.name) {
           if (hasUnattachedField) {
             result.add(Error(
               message:
-                  'ProxyApis with fields can not be used as attached fields: ${field.name}',
+                  'ProxyApis with unattached fields can not be used as attached fields: ${field.name}',
               lineNumber: _calculateLineNumberNullable(
                 source,
                 field.offset,
@@ -1032,7 +1032,7 @@ List<Error> _validateProxyApi(
         if (interfaceName == api.name) {
           result.add(Error(
             message:
-                'ProxyApis used as interfaces can only have callback methods: ${proxyApi.name}',
+                'ProxyApis used as interfaces can only have callback methods: `${proxyApi.name}` implements `${api.name}`',
           ));
         }
       }
@@ -1139,28 +1139,27 @@ List<Error> _validateProxyApi(
       if (!isProxyApi(field)) {
         result.add(Error(
           message:
-              'Static fields are considered attached fields and must be a ProxyApi: ${field.type.baseName}.',
+              'Static fields are considered attached fields and must be a ProxyApi: ${field.type.baseName}',
           lineNumber: _calculateLineNumberNullable(source, field.offset),
         ));
       } else if (field.type.isNullable) {
         result.add(Error(
           message:
-              'Static fields are considered attached fields and must not be nullable: ${field.type.baseName}.',
+              'Static fields are considered attached fields and must not be nullable: ${field.type.baseName}?',
           lineNumber: _calculateLineNumberNullable(source, field.offset),
         ));
       }
     } else if (field.isAttached) {
       if (!isProxyApi(field)) {
         result.add(Error(
-          message:
-              'Attached fields must be a ProxyApi: ${field.type.baseName}.',
+          message: 'Attached fields must be a ProxyApi: ${field.type.baseName}',
           lineNumber: _calculateLineNumberNullable(source, field.offset),
         ));
       }
       if (field.type.isNullable) {
         result.add(Error(
           message:
-              'Attached fields must not be nullable: ${field.type.baseName}.',
+              'Attached fields must not be nullable: ${field.type.baseName}?',
           lineNumber: _calculateLineNumberNullable(source, field.offset),
         ));
       }
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 7998733664ab..54d9034ebdb7 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -8,6 +8,7 @@ import 'dart:io';
 import 'package:pigeon/ast.dart';
 import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/pigeon_lib.dart';
+import 'package:test/expect.dart';
 import 'package:test/test.dart';
 
 class _ValidatorGeneratorAdapter implements GeneratorAdapter {
@@ -1354,4 +1355,215 @@ abstract class Api {
     expect(results.errors[0].message,
         contains('FlutterApi method parameters must not be optional'));
   });
+
+  test('simple parse ProxyApi', () {
+    const String code = '''
+@ProxyApi()
+abstract class MyClass {
+  MyClass();
+  late String aField;
+  late void Function() aCallbackMethod;
+  void aMethod();
+}
+''';
+    final ParseResults parseResult = parseSource(code);
+    expect(parseResult.errors.length, equals(0));
+    final Root root = parseResult.root;
+    expect(root.apis.length, equals(1));
+
+    final AstProxyApi proxyApi = root.apis.single as AstProxyApi;
+    expect(proxyApi.name, equals('MyClass'));
+    expect(proxyApi.constructors.single.name, equals(''));
+    expect(proxyApi.methods.length, equals(2));
+
+    for (final Method method in proxyApi.methods) {
+      if (method.location == ApiLocation.host) {
+        expect(method.name, equals('aMethod'));
+      } else if (method.location == ApiLocation.flutter) {
+        expect(method.name, equals('aCallbackMethod'));
+      }
+    }
+  });
+
+  group('ProxyApi validation', () {
+    test('error with using data class', () {
+      const String code = '''
+class DataClass {
+  late int input;
+}
+
+@ProxyApi()
+abstract class MyClass {
+  MyClass(DataClass input);
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors.length, equals(1));
+      expect(
+        parseResult.errors.single.message,
+        contains('ProxyApis do not support data classes'),
+      );
+    });
+
+    test('super class must be proxy api', () {
+      const String code = '''
+class DataClass {
+  late int input;
+}
+
+@ProxyApi()
+abstract class MyClass extends DataClass {
+  void aMethod();
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains('Super class of MyClass is not marked as a @ProxyApi'),
+      );
+    });
+
+    test('interface must be proxy api', () {
+      const String code = '''
+class DataClass {
+  late int input;
+}
+
+@ProxyApi()
+abstract class MyClass implements DataClass {
+  void aMethod();
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains('Interface of MyClass is not marked as a @ProxyApi'),
+      );
+    });
+
+    test('unattached fields can not be inherited', () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass extends MyOtherClass { }
+
+@ProxyApi()
+abstract class MyOtherClass {
+  late int aField;
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains(
+          'Unattached fields can not be inherited. Unattached field found for parent class: aField',
+        ),
+      );
+    });
+
+    test(
+        'api is not used as an attached field while having an unattached field',
+        () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass {
+  @attached
+  late MyOtherClass anAttachedField;
+}
+
+@ProxyApi()
+abstract class MyOtherClass {
+  late int aField;
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains(
+          'ProxyApis with unattached fields can not be used as attached fields: anAttachedField',
+        ),
+      );
+    });
+
+    test(
+        'api is not used as an attached field while having a required Flutter method',
+        () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass {
+  @attached
+  late MyOtherClass anAttachedField;
+}
+
+@ProxyApi()
+abstract class MyOtherClass {
+  late void Function() aCallbackMethod;
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains(
+          'ProxyApis with required callback methods can not be used as attached fields: anAttachedField',
+        ),
+      );
+    });
+
+    test('interfaces can only have callback methods', () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass implements MyOtherClass {
+}
+
+@ProxyApi()
+abstract class MyOtherClass {
+  MyOtherClass();
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains(
+          'ProxyApis used as interfaces can only have callback methods: `MyClass` implements `MyOtherClass`',
+        ),
+      );
+    });
+
+    test('attached fields must be a ProxyApi', () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass {
+  @attached
+  late int aField;
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains('Attached fields must be a ProxyApi: int'),
+      );
+    });
+
+    test('attached fields must not be nullable', () {
+      const String code = '''
+@ProxyApi()
+abstract class MyClass {
+  @attached
+  late MyClass? aField;
+}
+''';
+      final ParseResults parseResult = parseSource(code);
+      expect(parseResult.errors, isNotEmpty);
+      expect(
+        parseResult.errors[0].message,
+        contains('Attached fields must not be nullable: MyClass?'),
+      );
+    });
+  });
 }

From 155469f6e6ee6bae60aa1ef6718836e1ae323115 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 00:23:59 -0500
Subject: [PATCH 05/32] change required to isRequired

---
 packages/pigeon/lib/ast.dart                 | 4 ++--
 packages/pigeon/lib/pigeon_lib.dart          | 4 ++--
 packages/pigeon/test/cpp_generator_test.dart | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index db663f18bf38..cb1166a04c0d 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -30,7 +30,7 @@ class Method extends Node {
     required this.returnType,
     required this.parameters,
     required this.location,
-    this.required = true,
+    this.isRequired = true,
     this.isAsynchronous = false,
     this.isStatic = false,
     this.offset,
@@ -78,7 +78,7 @@ class Method extends Node {
   ///
   /// This flag is typically used to determine whether a callback method for
   /// a `ProxyApi` is nullable or not.
-  bool required;
+  bool isRequired;
 
   /// Whether this is a static method of a ProxyApi.
   bool isStatic;
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 1e69a4818415..e58f0cb94bbf 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -990,7 +990,7 @@ List<Error> _validateProxyApi(
 
   final bool hasUnattachedField = api.unattachedFields.isNotEmpty;
   final bool hasRequiredFlutterMethod =
-      api.flutterMethods.any((Method method) => method.required);
+      api.flutterMethods.any((Method method) => method.isRequired);
   for (final AstProxyApi proxyApi in proxyApis) {
     // Validate this api is not used as an attached field while either:
     // 1. Having an unattached field.
@@ -1881,7 +1881,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
             isNullable: returnType.question != null,
           ),
           location: ApiLocation.flutter,
-          required: type.question == null,
+          isRequired: type.question == null,
           isStatic: isStatic,
           parameters: parameters,
           isAsynchronous: _hasMetadata(node.metadata, 'async'),
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index af7865815d3a..861ba5082b46 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -37,7 +37,7 @@ void main() {
                 ),
                 name: 'input')
           ],
-          required: true,
+          isRequired: true,
           location: ApiLocation.host,
           returnType: TypeDeclaration(
             baseName: 'Output',

From 3a45694ab9b1458c10357946e033623a1a77e4d9 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 00:37:51 -0500
Subject: [PATCH 06/32] improve docs

---
 packages/pigeon/lib/cpp_generator.dart |  3 +--
 packages/pigeon/lib/pigeon_lib.dart    | 23 +++++++++++++----------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/packages/pigeon/lib/cpp_generator.dart b/packages/pigeon/lib/cpp_generator.dart
index 2ec8ccd00833..419695b4ed2b 100644
--- a/packages/pigeon/lib/cpp_generator.dart
+++ b/packages/pigeon/lib/cpp_generator.dart
@@ -175,7 +175,7 @@ class CppHeaderGenerator extends StructuredGenerator<CppOptions> {
         indent, anEnum.documentationComments, _docCommentSpec);
     indent.write('enum class ${anEnum.name} ');
     indent.addScoped('{', '};', () {
-      enumerate(anEnum.members, (int index, EnumMember member) {
+      enumerate(anEnum.members, (int index, final EnumMember member) {
         addDocumentationComments(
             indent, member.documentationComments, _docCommentSpec);
         indent.writeln(
@@ -784,7 +784,6 @@ class CppSourceGenerator extends StructuredGenerator<CppOptions> {
       final Iterable<_IndexedField> indexedFields = indexMap(
           getFieldsInSerializationOrder(classDefinition),
           (int index, NamedType field) => _IndexedField(index, field));
-
       final Iterable<_IndexedField> nullableFields = indexedFields
           .where((_IndexedField field) => field.field.type.isNullable);
       final Iterable<_IndexedField> nonNullableFields = indexedFields
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index e58f0cb94bbf..5de9cdb5492f 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -52,14 +52,14 @@ const Object async = _Asynchronous();
 
 /// Metadata to annotate the field of a ProxyApi as an Attached Field.
 ///
-/// Attached fields provide a synchronous [AstProxyApi] instance as a field
-/// for another [AstProxyApi].
+/// Attached fields provide a synchronous [ProxyApi] instance as a field for
+/// another [ProxyApi].
 ///
 /// Attached fields:
 /// * Must be nonnull.
-/// * Must be a ProxyApi type.
-/// * Must be a ProxyApi that contains any fields.
-/// * Must be a ProxyApi that does not have a required Flutter method.
+/// * Must be a ProxyApi (a class annotated with `@ProxyApi()`).
+/// * Must not contain any unattached fields.
+/// * Must not have a required callback Flutter method.
 ///
 /// Example generated code:
 ///
@@ -74,7 +74,10 @@ const Object async = _Asynchronous();
 /// to how constructors are implemented.
 const Object attached = _Attached();
 
-/// Metadata to annotate an method or an Attached Field of a ProxyApi as static.
+/// Metadata to annotate a field of a ProxyApi as static.
+///
+/// Static fields are the same as [attached] fields except the field is static
+/// and not attached to any instance of the ProxyApi.
 const Object static = _Static();
 
 /// Metadata annotation used to configure how Pigeon will generate code.
@@ -129,10 +132,10 @@ class FlutterApi {
 /// constructors, fields, methods and host↔Dart methods used to wrap a native
 /// class.
 ///
-/// The generated Dart class acts as a proxy to a native type and
-/// maintains instances automatically with an `InstanceManager`. The generated
-/// host language class implements methods to interact with class instances
-/// or static methods.
+/// The generated Dart class acts as a proxy to a native type and maintains
+/// instances automatically with an `InstanceManager`. The generated host
+/// language class implements methods to interact with class instances or static
+/// methods.
 class ProxyApi {
   /// Parametric constructor for [ProxyApi].
   const ProxyApi({this.superClass});

From 635035349ae25edc321b74a11e247caaa2ffc6db Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 12:46:21 -0500
Subject: [PATCH 07/32] fix lint errors and hide ProxyApi

---
 packages/pigeon/lib/pigeon.dart              | 2 +-
 packages/pigeon/test/cpp_generator_test.dart | 1 -
 packages/pigeon/test/pigeon_lib_test.dart    | 1 -
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/pigeon/lib/pigeon.dart b/packages/pigeon/lib/pigeon.dart
index 7f2fb7505fa8..e92619076c0b 100644
--- a/packages/pigeon/lib/pigeon.dart
+++ b/packages/pigeon/lib/pigeon.dart
@@ -9,5 +9,5 @@ export 'dart_generator.dart' show DartOptions;
 export 'java_generator.dart' show JavaOptions;
 export 'kotlin_generator.dart' show KotlinOptions;
 export 'objc_generator.dart' show ObjcOptions;
-export 'pigeon_lib.dart';
+export 'pigeon_lib.dart' hide ProxyApi;
 export 'swift_generator.dart' show SwiftOptions;
diff --git a/packages/pigeon/test/cpp_generator_test.dart b/packages/pigeon/test/cpp_generator_test.dart
index 861ba5082b46..42aa28c5361a 100644
--- a/packages/pigeon/test/cpp_generator_test.dart
+++ b/packages/pigeon/test/cpp_generator_test.dart
@@ -37,7 +37,6 @@ void main() {
                 ),
                 name: 'input')
           ],
-          isRequired: true,
           location: ApiLocation.host,
           returnType: TypeDeclaration(
             baseName: 'Output',
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 54d9034ebdb7..34516e8c0dea 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -8,7 +8,6 @@ import 'dart:io';
 import 'package:pigeon/ast.dart';
 import 'package:pigeon/generator_tools.dart';
 import 'package:pigeon/pigeon_lib.dart';
-import 'package:test/expect.dart';
 import 'package:test/test.dart';
 
 class _ValidatorGeneratorAdapter implements GeneratorAdapter {

From 4ce1e2146c73b257b7a4bfae0c230cfbfe6167da Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 12:49:33 -0500
Subject: [PATCH 08/32] add hide comment

---
 packages/pigeon/lib/pigeon.dart | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/pigeon/lib/pigeon.dart b/packages/pigeon/lib/pigeon.dart
index e92619076c0b..a2c6026e3117 100644
--- a/packages/pigeon/lib/pigeon.dart
+++ b/packages/pigeon/lib/pigeon.dart
@@ -9,5 +9,7 @@ export 'dart_generator.dart' show DartOptions;
 export 'java_generator.dart' show JavaOptions;
 export 'kotlin_generator.dart' show KotlinOptions;
 export 'objc_generator.dart' show ObjcOptions;
+// TODO(bparrishMines): Remove hide once implementation of the api is finished
+// for Dart and one host language.
 export 'pigeon_lib.dart' hide ProxyApi;
 export 'swift_generator.dart' show SwiftOptions;

From 22c30651d56303d3cddbb6270567051c8623b10f Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 12:53:51 -0500
Subject: [PATCH 09/32] test for recursive looks

---
 .../pigeon/test/generator_tools_test.dart     | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index 8264496d3343..c747eeda30b6 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -373,4 +373,97 @@ void main() {
 
     expect(dartPackageName, 'pigeon');
   });
+
+  test('recursiveGetSuperClassApisChain', () {
+    final AstProxyApi api = AstProxyApi(
+      name: 'Api',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+      superClassName: 'Api2',
+    );
+    final AstProxyApi superClassApi = AstProxyApi(
+      name: 'Api2',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+      superClassName: 'Api3',
+    );
+    final AstProxyApi superClassOfSuperClassApi = AstProxyApi(
+      name: 'Api3',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+    );
+
+    final List<AstProxyApi> apiChain = recursiveGetSuperClassApisChain(
+      api,
+      <AstProxyApi>[superClassOfSuperClassApi, api, superClassApi],
+    );
+
+    expect(
+      apiChain,
+      containsAllInOrder(<AstProxyApi>[
+        superClassApi,
+        superClassOfSuperClassApi,
+      ]),
+    );
+  });
+
+  test('recursiveFindAllInterfacesApis', () {
+    final AstProxyApi api = AstProxyApi(
+      name: 'Api',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+      interfacesNames: <String>{'Api2', 'Api3'},
+    );
+    final AstProxyApi interfaceApi = AstProxyApi(
+      name: 'Api2',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+      interfacesNames: <String>{'Api4', 'Api5'},
+    );
+    final AstProxyApi interfaceApi2 = AstProxyApi(
+      name: 'Api3',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+      interfacesNames: <String>{'Api5'},
+    );
+    final AstProxyApi interfaceOfInterfaceApi = AstProxyApi(
+      name: 'Api4',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+    );
+    final AstProxyApi interfaceOfInterfaceApi2 = AstProxyApi(
+      name: 'Api5',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <Field>[],
+    );
+
+    final Set<AstProxyApi> allInterfaces = recursiveFindAllInterfacesApis(
+      api,
+      <AstProxyApi>[
+        api,
+        interfaceApi,
+        interfaceApi2,
+        interfaceOfInterfaceApi,
+        interfaceOfInterfaceApi2,
+      ],
+    );
+
+    expect(
+      allInterfaces,
+      containsAll(<AstProxyApi>[
+        interfaceApi,
+        interfaceApi2,
+        interfaceOfInterfaceApi,
+        interfaceOfInterfaceApi2,
+      ]),
+    );
+  });
 }

From a14485edce2ce114de73cc79ebffb2e7e5e47b9d Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 12 Jan 2024 13:06:15 -0500
Subject: [PATCH 10/32] fix tools version

---
 packages/pigeon/lib/generator_tools.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 7fa2f967cf9a..43d26c388b44 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -13,7 +13,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '16.0.0';
+const String pigeonVersion = '16.0.1';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

From 360dd7a2073dd5aa598728cf6985c3d37de2a2e9 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Tue, 23 Jan 2024 18:23:05 -0500
Subject: [PATCH 11/32] review comments

---
 packages/pigeon/lib/ast.dart                  | 36 +++++++++++--------
 packages/pigeon/lib/generator_tools.dart      |  2 +-
 packages/pigeon/lib/pigeon_lib.dart           | 26 +++++++-------
 .../pigeon/test/generator_tools_test.dart     | 16 ++++-----
 4 files changed, 44 insertions(+), 36 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index cb1166a04c0d..51bcd215cccf 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -145,7 +145,7 @@ class AstProxyApi extends Api {
   final List<Constructor> constructors;
 
   /// List of fields inside the API.
-  List<Field> fields;
+  List<ApiField> fields;
 
   /// Name of the class this class considers the super class.
   final String? superClassName;
@@ -166,20 +166,22 @@ class AstProxyApi extends Api {
   /// All fields that are attached.
   ///
   /// See [attached].
-  Iterable<Field> get attachedFields => fields.where(
-        (Field field) => field.isAttached,
+  Iterable<ApiField> get attachedFields => fields.where(
+        (ApiField field) => field.isAttached,
       );
 
   /// All fields that are not attached.
   ///
   /// See [attached].
-  Iterable<Field> get unattachedFields => fields.where(
-        (Field field) => !field.isAttached,
+  Iterable<ApiField> get unattachedFields => fields.where(
+        (ApiField field) => !field.isAttached,
       );
 
   @override
   String toString() {
-    return '(ProxyApi name:$name methods:$methods documentationComments:$documentationComments superClassName:$superClassName interfacesNames:$interfacesNames)';
+    return '(ProxyApi name:$name methods:$methods field:$fields '
+        'documentationComments:$documentationComments '
+        'superClassName:$superClassName interfacesNames:$interfacesNames)';
   }
 }
 
@@ -206,9 +208,9 @@ class Constructor extends Method {
 }
 
 /// Represents a field of an API.
-class Field extends NamedType {
-  /// Constructor for [Field].
-  Field({
+class ApiField extends NamedType {
+  /// Constructor for [ApiField].
+  ApiField({
     required super.name,
     required super.type,
     super.offset,
@@ -229,8 +231,8 @@ class Field extends NamedType {
 
   /// Returns a copy of [Parameter] instance with new attached [TypeDeclaration].
   @override
-  Field copyWithType(TypeDeclaration type) {
-    return Field(
+  ApiField copyWithType(TypeDeclaration type) {
+    return ApiField(
       name: name,
       type: type,
       offset: offset,
@@ -239,6 +241,12 @@ class Field extends NamedType {
       isStatic: isStatic,
     );
   }
+
+  @override
+  String toString() {
+    return '(Field name:$name type:$type isAttached:$isAttached '
+        'isStatic:$isStatic documentationComments:$documentationComments)';
+  }
 }
 
 /// Represents a collection of [Method]s.
@@ -315,12 +323,12 @@ class TypeDeclaration {
   /// Associated [Class], if any.
   final Class? associatedClass;
 
-  /// Associated [AstProxyApi], if any.
-  final AstProxyApi? associatedProxyApi;
-
   /// Whether the [TypeDeclaration] has an [associatedProxyApi].
   bool get isProxyApi => associatedProxyApi != null;
 
+  /// Associated [AstProxyApi], if any.
+  final AstProxyApi? associatedProxyApi;
+
   @override
   int get hashCode {
     // This has to be implemented because TypeDeclaration is used as a Key to a
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 43d26c388b44..65f07b342450 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -446,7 +446,7 @@ Map<TypeDeclaration, List<int>> getReferencedTypes(
           );
         }
       }
-      for (final Field field in api.fields) {
+      for (final ApiField field in api.fields) {
         references.addMany(_getTypeArguments(field.type), field.offset);
       }
     }
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 5de9cdb5492f..7b60e526b2f4 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -999,7 +999,7 @@ List<Error> _validateProxyApi(
     // 1. Having an unattached field.
     // 2. Having a required Flutter method.
     if (hasUnattachedField || hasRequiredFlutterMethod) {
-      for (final Field field in proxyApi.attachedFields) {
+      for (final ApiField field in proxyApi.attachedFields) {
         if (field.type.baseName == api.name) {
           if (hasUnattachedField) {
             result.add(Error(
@@ -1049,7 +1049,7 @@ List<Error> _validateProxyApi(
         result.add(unsupportedDataClassError(parameter));
       }
 
-      if (api.fields.any((Field field) => field.name == parameter.name) ||
+      if (api.fields.any((ApiField field) => field.name == parameter.name) ||
           api.flutterMethods
               .any((Method method) => method.name == parameter.name)) {
         result.add(Error(
@@ -1135,7 +1135,7 @@ List<Error> _validateProxyApi(
   }
 
   // Validate fields
-  for (final Field field in api.fields) {
+  for (final ApiField field in api.fields) {
     if (isDataClass(field)) {
       result.add(unsupportedDataClassError(field));
     } else if (field.isStatic) {
@@ -1287,7 +1287,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       final List<NamedType> fields = <NamedType>[];
       for (final NamedType field in classDefinition.fields) {
         fields.add(field.copyWithType(
-          _attachClassesEnumsAndProxyApis(field.type),
+          _attachAssociatedDefinition(field.type),
         ));
       }
       classDefinition.fields = fields;
@@ -1298,27 +1298,27 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
         final List<Parameter> paramList = <Parameter>[];
         for (final Parameter param in func.parameters) {
           paramList.add(param.copyWithType(
-            _attachClassesEnumsAndProxyApis(param.type),
+            _attachAssociatedDefinition(param.type),
           ));
         }
         func.parameters = paramList;
-        func.returnType = _attachClassesEnumsAndProxyApis(func.returnType);
+        func.returnType = _attachAssociatedDefinition(func.returnType);
       }
       if (api is AstProxyApi) {
         for (final Constructor constructor in api.constructors) {
           final List<Parameter> paramList = <Parameter>[];
           for (final Parameter param in constructor.parameters) {
             paramList.add(
-              param.copyWithType(_attachClassesEnumsAndProxyApis(param.type)),
+              param.copyWithType(_attachAssociatedDefinition(param.type)),
             );
           }
           constructor.parameters = paramList;
         }
 
-        final List<Field> fieldList = <Field>[];
-        for (final Field field in api.fields) {
+        final List<ApiField> fieldList = <ApiField>[];
+        for (final ApiField field in api.fields) {
           fieldList.add(field.copyWithType(
-            _attachClassesEnumsAndProxyApis(field.type),
+            _attachAssociatedDefinition(field.type),
           ));
         }
         api.fields = fieldList;
@@ -1334,7 +1334,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     );
   }
 
-  TypeDeclaration _attachClassesEnumsAndProxyApis(TypeDeclaration type) {
+  TypeDeclaration _attachAssociatedDefinition(TypeDeclaration type) {
     final Enum? assocEnum = _enums.firstWhereOrNull(
         (Enum enumDefinition) => enumDefinition.name == type.baseName);
     final Class? assocClass = _classes.firstWhereOrNull(
@@ -1512,7 +1512,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
           name: node.name.lexeme,
           methods: <Method>[],
           constructors: <Constructor>[],
-          fields: <Field>[],
+          fields: <ApiField>[],
           superClassName:
               superClassName ?? node.extendsClause?.superclass.name2.lexeme,
           interfacesNames: node.implementsClause?.interfaces
@@ -1906,7 +1906,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       } else {
         final dart_ast.TypeArgumentList? typeArguments = type.typeArguments;
         (_currentApi as AstProxyApi?)!.fields.add(
-              Field(
+              ApiField(
                 type: TypeDeclaration(
                   baseName: _getNamedTypeQualifiedName(type),
                   isNullable: type.question != null,
diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index c747eeda30b6..bec70e52c5ad 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -379,21 +379,21 @@ void main() {
       name: 'Api',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
       superClassName: 'Api2',
     );
     final AstProxyApi superClassApi = AstProxyApi(
       name: 'Api2',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
       superClassName: 'Api3',
     );
     final AstProxyApi superClassOfSuperClassApi = AstProxyApi(
       name: 'Api3',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
     );
 
     final List<AstProxyApi> apiChain = recursiveGetSuperClassApisChain(
@@ -415,34 +415,34 @@ void main() {
       name: 'Api',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
       interfacesNames: <String>{'Api2', 'Api3'},
     );
     final AstProxyApi interfaceApi = AstProxyApi(
       name: 'Api2',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
       interfacesNames: <String>{'Api4', 'Api5'},
     );
     final AstProxyApi interfaceApi2 = AstProxyApi(
       name: 'Api3',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
       interfacesNames: <String>{'Api5'},
     );
     final AstProxyApi interfaceOfInterfaceApi = AstProxyApi(
       name: 'Api4',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
     );
     final AstProxyApi interfaceOfInterfaceApi2 = AstProxyApi(
       name: 'Api5',
       methods: <Method>[],
       constructors: <Constructor>[],
-      fields: <Field>[],
+      fields: <ApiField>[],
     );
 
     final Set<AstProxyApi> allInterfaces = recursiveFindAllInterfacesApis(

From ea9f7c3c1f8771382403ebc4d205e453f9406918 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 24 Jan 2024 13:41:28 -0500
Subject: [PATCH 12/32] switch to a method that looks for matching prefix

---
 packages/pigeon/lib/pigeon_lib.dart | 126 ++++++++++++++--------------
 1 file changed, 62 insertions(+), 64 deletions(-)

diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 7b60e526b2f4..fc890be6d27f 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -867,18 +867,18 @@ List<Error> _validateAst(Root root, String source) {
                 'Parameters must specify their type in method "${method.name}" in API: "${api.name}"',
             lineNumber: _calculateLineNumberNullable(source, param.offset),
           ));
-        } else if (param.name.startsWith('__pigeon_')) {
-          result.add(Error(
-            message:
-                'Parameter name must not begin with "__pigeon_" in method "${method.name}" in API: "${api.name}"',
-            lineNumber: _calculateLineNumberNullable(source, param.offset),
-          ));
-        } else if (param.name == 'pigeonChannelCodec') {
-          result.add(Error(
-            message:
-                'Parameter name must not be "pigeonChannelCodec" in method "${method.name}" in API: "${api.name}"',
-            lineNumber: _calculateLineNumberNullable(source, param.offset),
-          ));
+        } else {
+          final String? matchingPrefix = _findMatchingPrefixOrNull(
+            method.name,
+            prefixes: <String>['__pigeon_', 'pigeonChannelCodec'],
+          );
+          if (matchingPrefix != null) {
+            result.add(Error(
+              message:
+                  'Parameter name must not begin with "$matchingPrefix" in method "${method.name} in API: "${api.name}"',
+              lineNumber: _calculateLineNumberNullable(source, param.offset),
+            ));
+          }
         }
         if (api is AstFlutterApi) {
           if (!param.isPositional) {
@@ -1065,30 +1065,23 @@ List<Error> _validateProxyApi(
               'Parameters must specify their type in constructor "${constructor.name}" in API: "${api.name}"',
           lineNumber: _calculateLineNumberNullable(source, parameter.offset),
         ));
-      } else if (parameter.name.startsWith('__pigeon_')) {
-        result.add(Error(
-          message:
-              'Parameter name must not begin with "__pigeon_" in constructor "${constructor.name}" in API: "${api.name}"',
-          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
-        ));
-      } else if (parameter.name == 'pigeonChannelCodec') {
-        result.add(Error(
-          message:
-              'Parameter name must not be "pigeonChannelCodec" in constructor "${constructor.name}" in API: "${api.name}"',
-          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
-        ));
-      } else if (parameter.name.startsWith(classNamePrefix)) {
-        result.add(Error(
-          message:
-              'Parameter name must not begin with "$classNamePrefix" in constructor "${constructor.name}" in API: "${api.name}"',
-          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
-        ));
-      } else if (parameter.name.startsWith(classMemberNamePrefix)) {
-        result.add(Error(
-          message:
-              'Parameter name must not begin with "$classMemberNamePrefix" in constructor "${constructor.name}" in API: "${api.name}"',
-          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
-        ));
+      } else {
+        final String? matchingPrefix = _findMatchingPrefixOrNull(
+          parameter.name,
+          prefixes: <String>[
+            '__pigeon_',
+            'pigeonChannelCodec',
+            classNamePrefix,
+            classMemberNamePrefix,
+          ],
+        );
+        if (matchingPrefix != null) {
+          result.add(Error(
+            message:
+                'Parameter name must not begin with "$matchingPrefix" in constructor "${constructor.name} in API: "${api.name}"',
+            lineNumber: _calculateLineNumberNullable(source, parameter.offset),
+          ));
+        }
       }
     }
     if (constructor.swiftFunction.isNotEmpty) {
@@ -1111,16 +1104,17 @@ List<Error> _validateProxyApi(
         result.add(unsupportedDataClassError(parameter));
       }
 
-      if (parameter.name.startsWith(classNamePrefix)) {
-        result.add(Error(
-          message:
-              'Parameter name must not begin with "$classNamePrefix" in method "${method.name}" in API: "${api.name}"',
-          lineNumber: _calculateLineNumberNullable(source, parameter.offset),
-        ));
-      } else if (parameter.name.startsWith(classMemberNamePrefix)) {
+      final String? matchingPrefix = _findMatchingPrefixOrNull(
+        parameter.name,
+        prefixes: <String>[
+          classNamePrefix,
+          classMemberNamePrefix,
+        ],
+      );
+      if (matchingPrefix != null) {
         result.add(Error(
           message:
-              'Parameter name must not begin with "$classMemberNamePrefix" in method "${method.name}" in API: "${api.name}"',
+              'Parameter name must not begin with "$matchingPrefix" in method "${method.name} in API: "${api.name}"',
           lineNumber: _calculateLineNumberNullable(source, parameter.offset),
         ));
       }
@@ -1168,28 +1162,19 @@ List<Error> _validateProxyApi(
       }
     }
 
-    if (field.name.startsWith('__pigeon_')) {
-      result.add(Error(
-        message:
-            'Field name must not begin with "__pigeon_" in API: "${api.name}"',
-        lineNumber: _calculateLineNumberNullable(source, field.offset),
-      ));
-    } else if (field.name == 'pigeonChannelCodec') {
-      result.add(Error(
-        message:
-            'Field name must not be "pigeonChannelCodec" in API: "${api.name}"',
-        lineNumber: _calculateLineNumberNullable(source, field.offset),
-      ));
-    } else if (field.name.startsWith(classNamePrefix)) {
-      result.add(Error(
-        message:
-            'Field name must not begin with "$classNamePrefix" in API: "${api.name}"',
-        lineNumber: _calculateLineNumberNullable(source, field.offset),
-      ));
-    } else if (field.name.startsWith(classMemberNamePrefix)) {
+    final String? matchingPrefix = _findMatchingPrefixOrNull(
+      field.name,
+      prefixes: <String>[
+        '__pigeon_',
+        'pigeonChannelCodec',
+        classNamePrefix,
+        classMemberNamePrefix,
+      ],
+    );
+    if (matchingPrefix != null) {
       result.add(Error(
         message:
-            'Field name must not begin with "$classMemberNamePrefix" in API: "${api.name}"',
+            'Field name must not begin with "$matchingPrefix" in API: "${api.name}"',
         lineNumber: _calculateLineNumberNullable(source, field.offset),
       ));
     }
@@ -1198,6 +1183,19 @@ List<Error> _validateProxyApi(
   return result;
 }
 
+String? _findMatchingPrefixOrNull(
+  String value, {
+  required List<String> prefixes,
+}) {
+  for (final String prefix in prefixes) {
+    if (value.startsWith(prefix)) {
+      return prefix;
+    }
+  }
+
+  return null;
+}
+
 class _FindInitializer extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
   dart_ast.Expression? initializer;
   @override

From 33b2e07f91e131c3d625521d1839defff2901e1f Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 24 Jan 2024 14:10:20 -0500
Subject: [PATCH 13/32] avoid loops

---
 packages/pigeon/lib/generator_tools.dart      | 11 +++++--
 .../pigeon/test/generator_tools_test.dart     | 31 +++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 65f07b342450..be1a8bd6d92a 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -623,7 +623,8 @@ String? deducePackageName(String mainDartFile) {
 /// interfaces.
 ///
 /// This method assumes that all interfaces names can be found in
-/// [allProxyApis]. Otherwise, throws an [ArgumentError].
+/// [allProxyApis] and an api doesn't contains itself as an interface.
+/// Otherwise, throws an [ArgumentError].
 Set<AstProxyApi> recursiveFindAllInterfacesApis(
   AstProxyApi api,
   Iterable<AstProxyApi> allProxyApis,
@@ -638,14 +639,18 @@ Set<AstProxyApi> recursiveFindAllInterfacesApis(
 
   if (interfacesApis.length != api.interfacesNames.length) {
     throw ArgumentError(
-      'Could not find a ProxyApi for every interface name: '
+      'Could not find a valid ProxyApi for every interface name: '
       '${api.interfacesNames}, ${allProxyApis.map((Api api) => api.name)}',
     );
   }
 
+  // This removes the current api since it would be invalid for it to be a
+  // super class of itself.
+  final Set<AstProxyApi> allProxyApisWithoutCurrent =
+      Set<AstProxyApi>.from(allProxyApis)..remove(api);
   for (final AstProxyApi proxyApi in Set<AstProxyApi>.from(interfacesApis)) {
     interfacesApis.addAll(
-      recursiveFindAllInterfacesApis(proxyApi, allProxyApis),
+      recursiveFindAllInterfacesApis(proxyApi, allProxyApisWithoutCurrent),
     );
   }
 
diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index bec70e52c5ad..344a98cd79f4 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -466,4 +466,35 @@ void main() {
       ]),
     );
   });
+
+  test(
+      'recursiveFindAllInterfacesApis throws error if api recursively implements itself',
+      () {
+    final AstProxyApi a = AstProxyApi(
+      name: 'A',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <ApiField>[],
+      interfacesNames: <String>{'B'},
+    );
+    final AstProxyApi b = AstProxyApi(
+      name: 'B',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <ApiField>[],
+      interfacesNames: <String>{'C'},
+    );
+    final AstProxyApi c = AstProxyApi(
+      name: 'C',
+      methods: <Method>[],
+      constructors: <Constructor>[],
+      fields: <ApiField>[],
+      interfacesNames: <String>{'A'},
+    );
+
+    expect(
+      () => recursiveFindAllInterfacesApis(a, <AstProxyApi>[a, b, c]),
+      throwsArgumentError,
+    );
+  });
 }

From c8db9c8bf0218f14a0d4e188fee9233b70873ec9 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 24 Jan 2024 14:15:31 -0500
Subject: [PATCH 14/32] fix test

---
 packages/pigeon/test/dart_generator_test.dart | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 63ca9c2a4a3b..4c96bd7d74af 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -1778,15 +1778,16 @@ name: foobar
   test('generate wrapResponse if is generating tests', () {
     final Root root = Root(
       apis: <Api>[
-        Api(
+        AstHostApi(
             name: 'Api',
-            location: ApiLocation.host,
             dartHostTestHandler: 'ApiMock',
             methods: <Method>[
               Method(
-                  name: 'foo',
-                  returnType: const TypeDeclaration.voidDeclaration(),
-                  parameters: <Parameter>[])
+                name: 'foo',
+                location: ApiLocation.host,
+                returnType: const TypeDeclaration.voidDeclaration(),
+                parameters: <Parameter>[],
+              )
             ])
       ],
       classes: <Class>[],

From b414381729ebc16d50a063f668051e1010821121 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Thu, 25 Jan 2024 16:33:21 -0500
Subject: [PATCH 15/32] change superClass and interfaces to TypeDeclarations

---
 packages/pigeon/lib/ast.dart                  |  11 +-
 packages/pigeon/lib/generator_tools.dart      | 109 +++++++-------
 packages/pigeon/lib/pigeon_lib.dart           | 139 ++++++++++--------
 packages/pigeon/pubspec.yaml                  |   2 +-
 .../pigeon/test/generator_tools_test.dart     | 101 ++++++++-----
 5 files changed, 208 insertions(+), 154 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 51bcd215cccf..0c48faa45456 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -137,8 +137,8 @@ class AstProxyApi extends Api {
     super.documentationComments = const <String>[],
     required this.constructors,
     required this.fields,
-    this.superClassName,
-    this.interfacesNames = const <String>{},
+    this.superClass,
+    this.interfaces = const <TypeDeclaration>{},
   });
 
   /// List of constructors inside the API.
@@ -148,10 +148,10 @@ class AstProxyApi extends Api {
   List<ApiField> fields;
 
   /// Name of the class this class considers the super class.
-  final String? superClassName;
+  TypeDeclaration? superClass;
 
   /// Name of the classes this class considers to be implemented.
-  final Set<String> interfacesNames;
+  Set<TypeDeclaration> interfaces;
 
   /// Methods implemented in the host platform language.
   Iterable<Method> get hostMethods => methods.where(
@@ -181,7 +181,7 @@ class AstProxyApi extends Api {
   String toString() {
     return '(ProxyApi name:$name methods:$methods field:$fields '
         'documentationComments:$documentationComments '
-        'superClassName:$superClassName interfacesNames:$interfacesNames)';
+        'superClassName:$superClass interfacesNames:$interfaces)';
   }
 }
 
@@ -428,6 +428,7 @@ class NamedType extends Node {
   final List<String> documentationComments;
 
   /// Returns a copy of [NamedType] instance with new attached [TypeDeclaration].
+  @mustBeOverridden
   NamedType copyWithType(TypeDeclaration type) {
     return NamedType(
       name: name,
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 6f478dc39888..b9aec2b27994 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -622,39 +622,43 @@ String? deducePackageName(String mainDartFile) {
 /// Recursively search for all the interfaces apis from a list of names of
 /// interfaces.
 ///
-/// This method assumes that all interfaces names can be found in
-/// [allProxyApis] and an api doesn't contains itself as an interface.
-/// Otherwise, throws an [ArgumentError].
-Set<AstProxyApi> recursiveFindAllInterfacesApis(
-  AstProxyApi api,
-  Iterable<AstProxyApi> allProxyApis,
-) {
-  final Set<AstProxyApi> interfacesApis = <AstProxyApi>{};
-
-  for (final AstProxyApi proxyApi in allProxyApis) {
-    if (api.interfacesNames.contains(proxyApi.name)) {
-      interfacesApis.add(proxyApi);
-    }
-  }
+/// This method assumes that all interfaces are ProxyApis and an api doesn't
+/// contains itself as an interface. Otherwise, throws an [ArgumentError].
+Set<AstProxyApi> recursiveFindAllInterfaceApis(
+  AstProxyApi api, {
+  Set<AstProxyApi> seenApis = const <AstProxyApi>{},
+}) {
+  final Set<AstProxyApi> allInterfaces = <AstProxyApi>{};
+
+  allInterfaces.addAll(
+    api.interfaces.map(
+      (TypeDeclaration type) {
+        if (!type.isProxyApi) {
+          throw ArgumentError(
+            'Could not find a valid ProxyApi for an interface: $type',
+          );
+        } else if (seenApis.contains(type.associatedProxyApi)) {
+          throw ArgumentError(
+            'A ProxyApi cannot be a super class of itself: ${type.baseName}',
+          );
+        }
+        return type.associatedProxyApi!;
+      },
+    ),
+  );
 
-  if (interfacesApis.length != api.interfacesNames.length) {
-    throw ArgumentError(
-      'Could not find a valid ProxyApi for every interface name: '
-      '${api.interfacesNames}, ${allProxyApis.map((Api api) => api.name)}',
-    );
-  }
+  // Adds the current api since it would be invalid for it to be an interface
+  // of itself.
+  final Set<AstProxyApi> newSeenApis = <AstProxyApi>{...seenApis, api};
 
-  // This removes the current api since it would be invalid for it to be a
-  // super class of itself.
-  final Set<AstProxyApi> allProxyApisWithoutCurrent =
-      Set<AstProxyApi>.from(allProxyApis)..remove(api);
-  for (final AstProxyApi proxyApi in Set<AstProxyApi>.from(interfacesApis)) {
-    interfacesApis.addAll(
-      recursiveFindAllInterfacesApis(proxyApi, allProxyApisWithoutCurrent),
-    );
+  for (final AstProxyApi interfaceApi in <AstProxyApi>{...allInterfaces}) {
+    allInterfaces.addAll(recursiveFindAllInterfaceApis(
+      interfaceApi,
+      seenApis: newSeenApis,
+    ));
   }
 
-  return interfacesApis;
+  return allInterfaces;
 }
 
 /// Creates a list of ProxyApis where each `extends` the ProxyApi that follows
@@ -665,45 +669,40 @@ Set<AstProxyApi> recursiveFindAllInterfacesApis(
 /// This method assumes the super classes of each ProxyApi doesn't create a
 /// loop. Throws a [ArgumentError] if a loop is found.
 ///
-/// This method also assumes that all super class names can be found in
-/// [allProxyApis]. Otherwise, throws an [ArgumentError].
-List<AstProxyApi> recursiveGetSuperClassApisChain(
-  AstProxyApi proxyApi,
-  Iterable<AstProxyApi> allProxyApis,
-) {
-  final List<AstProxyApi> proxyApis = <AstProxyApi>[];
+/// This method also assumes that all super classes are ProxyApis. Otherwise,
+/// throws an [ArgumentError].
+List<AstProxyApi> recursiveGetSuperClassApisChain(AstProxyApi api) {
+  final List<AstProxyApi> superClassChain = <AstProxyApi>[];
 
-  String? currentProxyApiName = proxyApi.superClassName;
-  while (currentProxyApiName != null) {
-    if (proxyApis.length > allProxyApis.length) {
-      final Iterable<String> apiNames = proxyApis.map(
-        (AstProxyApi api) => api.name,
-      );
+  if (api.superClass != null && !api.superClass!.isProxyApi) {
+    throw ArgumentError(
+      'Could not find a ProxyApi for super class: ${api.superClass!.baseName}',
+    );
+  }
+
+  AstProxyApi? currentProxyApi = api.superClass?.associatedProxyApi;
+  while (currentProxyApi != null) {
+    if (superClassChain.contains(currentProxyApi)) {
       throw ArgumentError(
         'Loop found when processing super classes for a ProxyApi: '
-        '${proxyApi.name},${apiNames.join(',')}',
+        '${api.name}, ${superClassChain.map((AstProxyApi api) => api.name)}',
       );
     }
 
-    AstProxyApi? nextProxyApi;
-    for (final AstProxyApi node in allProxyApis) {
-      if (currentProxyApiName == node.name) {
-        nextProxyApi = node;
-        proxyApis.add(node);
-      }
-    }
+    superClassChain.add(currentProxyApi);
 
-    if (nextProxyApi == null) {
+    if (currentProxyApi.superClass != null &&
+        !currentProxyApi.superClass!.isProxyApi) {
       throw ArgumentError(
-        'Could not find a ProxyApi for every super class name: '
-        '$currentProxyApiName, ${allProxyApis.map((Api api) => api.name)}',
+        'Could not find a ProxyApi for super class: '
+        '${currentProxyApi.superClass!.baseName}',
       );
     }
 
-    currentProxyApiName = nextProxyApi.superClassName;
+    currentProxyApi = currentProxyApi.superClass?.associatedProxyApi;
   }
 
-  return proxyApis;
+  return superClassChain;
 }
 
 /// Enum to specify api type when generating code.
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index d5193f223ac1..187aa3466b2a 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -951,35 +951,24 @@ List<Error> _validateProxyApi(
     );
   }
 
-  // Validate super class is another ProxyApi
-  final String? superClassName = api.superClassName;
-  if (api.superClassName != null &&
-      !proxyApis.any((AstProxyApi api) => api.name == superClassName)) {
-    result.add(Error(
-      message:
-          'Super class of ${api.name} is not marked as a @ProxyApi: $superClassName',
-    ));
-  }
+  AstProxyApi? directSuperClass;
 
-  // Validate all interfaces are other ProxyApis
-  for (final String interfaceName in api.interfacesNames) {
-    if (!proxyApis.any((AstProxyApi api) => api.name == interfaceName)) {
-      result.add(Error(
-        message:
-            'Interface of ${api.name} is not marked as a @ProxyApi: $interfaceName',
-      ));
+  // Validate direct super class is another ProxyApi
+  if (api.superClass != null) {
+    directSuperClass = proxyApis.firstWhereOrNull(
+      (AstProxyApi proxyApi) => proxyApi.name == api.superClass?.baseName,
+    );
+    if (directSuperClass == null) {
+      result.add(
+        Error(
+          message: 'Super class of ${api.name} is not marked as a @ProxyApi: '
+              '${api.superClass?.baseName}',
+        ),
+      );
     }
   }
 
-  List<AstProxyApi>? superClassChain;
-  try {
-    superClassChain = recursiveGetSuperClassApisChain(api, proxyApis);
-  } catch (error) {
-    result.add(Error(message: error.toString()));
-  }
-
   // Validate that the api does not inherit an unattached field from its super class.
-  final AstProxyApi? directSuperClass = superClassChain?.firstOrNull;
   if (directSuperClass != null &&
       directSuperClass.unattachedFields.isNotEmpty) {
     result.add(Error(
@@ -992,6 +981,19 @@ List<Error> _validateProxyApi(
     ));
   }
 
+  // Validate all interfaces are other ProxyApis
+  final Iterable<String> interfaceNames = api.interfaces.map(
+    (TypeDeclaration type) => type.baseName,
+  );
+  for (final String interfaceName in interfaceNames) {
+    if (!proxyApis.any((AstProxyApi api) => api.name == interfaceName)) {
+      result.add(Error(
+        message:
+            'Interface of ${api.name} is not marked as a @ProxyApi: $interfaceName',
+      ));
+    }
+  }
+
   final bool hasUnattachedField = api.unattachedFields.isNotEmpty;
   final bool hasRequiredFlutterMethod =
       api.flutterMethods.any((Method method) => method.isRequired);
@@ -1032,7 +1034,10 @@ List<Error> _validateProxyApi(
         api.constructors.isEmpty &&
         api.fields.isEmpty;
     if (!isValidInterfaceProxyApi) {
-      for (final String interfaceName in proxyApi.interfacesNames) {
+      final Iterable<String> interfaceNames = proxyApi.interfaces.map(
+        (TypeDeclaration type) => type.baseName,
+      );
+      for (final String interfaceName in interfaceNames) {
         if (interfaceName == api.name) {
           result.add(Error(
             message:
@@ -1283,44 +1288,34 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       }
     }
     for (final Class classDefinition in referencedClasses) {
-      final List<NamedType> fields = <NamedType>[];
-      for (final NamedType field in classDefinition.fields) {
-        fields.add(field.copyWithType(
-          _attachAssociatedDefinition(field.type),
-        ));
-      }
-      classDefinition.fields = fields;
+      classDefinition.fields = _attachAssociatedDefinitions(
+        classDefinition.fields,
+      );
     }
 
     for (final Api api in _apis) {
       for (final Method func in api.methods) {
-        final List<Parameter> paramList = <Parameter>[];
-        for (final Parameter param in func.parameters) {
-          paramList.add(param.copyWithType(
-            _attachAssociatedDefinition(param.type),
-          ));
-        }
-        func.parameters = paramList;
+        func.parameters = _attachAssociatedDefinitions(func.parameters);
         func.returnType = _attachAssociatedDefinition(func.returnType);
       }
       if (api is AstProxyApi) {
         for (final Constructor constructor in api.constructors) {
-          final List<Parameter> paramList = <Parameter>[];
-          for (final Parameter param in constructor.parameters) {
-            paramList.add(
-              param.copyWithType(_attachAssociatedDefinition(param.type)),
-            );
-          }
-          constructor.parameters = paramList;
+          constructor.parameters = _attachAssociatedDefinitions(
+            constructor.parameters,
+          );
         }
 
-        final List<ApiField> fieldList = <ApiField>[];
-        for (final ApiField field in api.fields) {
-          fieldList.add(field.copyWithType(
-            _attachAssociatedDefinition(field.type),
-          ));
+        api.fields = _attachAssociatedDefinitions(api.fields);
+
+        if (api.superClass != null) {
+          api.superClass = _attachAssociatedDefinition(api.superClass!);
+        }
+
+        final Set<TypeDeclaration> newInterfaceSet = <TypeDeclaration>{};
+        for (final TypeDeclaration interface in api.interfaces) {
+          newInterfaceSet.add(_attachAssociatedDefinition(interface));
         }
-        api.fields = fieldList;
+        api.interfaces = newInterfaceSet;
       }
     }
 
@@ -1352,6 +1347,16 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
     return type;
   }
 
+  List<T> _attachAssociatedDefinitions<T extends NamedType>(Iterable<T> types) {
+    final List<T> result = <T>[];
+    for (final NamedType type in types) {
+      result.add(
+        type.copyWithType(_attachAssociatedDefinition(type.type)) as T,
+      );
+    }
+    return result;
+  }
+
   Object _expressionToMap(dart_ast.Expression expression) {
     if (expression is dart_ast.MethodInvocation) {
       final Map<String, Object> result = <String, Object>{};
@@ -1497,6 +1502,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
         }
 
         final String? superClassName = annotationMap['superClass'] as String?;
+        TypeDeclaration? superClass;
         if (superClassName != null && node.extendsClause != null) {
           _errors.add(
             Error(
@@ -1505,6 +1511,27 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
               lineNumber: _calculateLineNumber(source, node.offset),
             ),
           );
+        } else if (superClassName != null) {
+          superClass = TypeDeclaration(
+            baseName: superClassName,
+            isNullable: false,
+          );
+        } else if (node.extendsClause != null) {
+          superClass = TypeDeclaration(
+            baseName: node.extendsClause!.superclass.name2.lexeme,
+            isNullable: false,
+          );
+        }
+
+        final Set<TypeDeclaration> interfaces = <TypeDeclaration>{};
+        if (node.implementsClause != null) {
+          for (final dart_ast.NamedType type
+              in node.implementsClause!.interfaces) {
+            interfaces.add(TypeDeclaration(
+              baseName: type.name2.lexeme,
+              isNullable: false,
+            ));
+          }
         }
 
         _currentApi = AstProxyApi(
@@ -1512,12 +1539,8 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
           methods: <Method>[],
           constructors: <Constructor>[],
           fields: <ApiField>[],
-          superClassName:
-              superClassName ?? node.extendsClause?.superclass.name2.lexeme,
-          interfacesNames: node.implementsClause?.interfaces
-                  .map<String>((dart_ast.NamedType type) => type.name2.lexeme)
-                  .toSet() ??
-              <String>{},
+          superClass: superClass,
+          interfaces: interfaces,
           documentationComments:
               _documentationCommentsParser(node.documentationComment?.tokens),
         );
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 1f001eae6cb5..e077f7d81324 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -11,7 +11,7 @@ dependencies:
   analyzer: ">=5.13.0 <7.0.0"
   args: ^2.1.0
   collection: ^1.15.0
-  meta: ^1.7.0
+  meta: ^1.9.0
   path: ^1.8.0
   yaml: ^3.1.1
 
diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index 344a98cd79f4..6b43b93eecc5 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -375,31 +375,36 @@ void main() {
   });
 
   test('recursiveGetSuperClassApisChain', () {
-    final AstProxyApi api = AstProxyApi(
-      name: 'Api',
+    final AstProxyApi superClassOfSuperClassApi = AstProxyApi(
+      name: 'Api3',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      superClassName: 'Api2',
     );
     final AstProxyApi superClassApi = AstProxyApi(
       name: 'Api2',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      superClassName: 'Api3',
+      superClass: TypeDeclaration(
+        baseName: 'Api3',
+        isNullable: false,
+        associatedProxyApi: superClassOfSuperClassApi,
+      ),
     );
-    final AstProxyApi superClassOfSuperClassApi = AstProxyApi(
-      name: 'Api3',
+    final AstProxyApi api = AstProxyApi(
+      name: 'Api',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
+      superClass: TypeDeclaration(
+        baseName: 'Api2',
+        isNullable: false,
+        associatedProxyApi: superClassApi,
+      ),
     );
 
-    final List<AstProxyApi> apiChain = recursiveGetSuperClassApisChain(
-      api,
-      <AstProxyApi>[superClassOfSuperClassApi, api, superClassApi],
-    );
+    final List<AstProxyApi> apiChain = recursiveGetSuperClassApisChain(api);
 
     expect(
       apiChain,
@@ -411,50 +416,69 @@ void main() {
   });
 
   test('recursiveFindAllInterfacesApis', () {
-    final AstProxyApi api = AstProxyApi(
-      name: 'Api',
+    final AstProxyApi interfaceOfInterfaceApi2 = AstProxyApi(
+      name: 'Api5',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'Api2', 'Api3'},
     );
-    final AstProxyApi interfaceApi = AstProxyApi(
-      name: 'Api2',
+    final AstProxyApi interfaceOfInterfaceApi = AstProxyApi(
+      name: 'Api4',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'Api4', 'Api5'},
     );
     final AstProxyApi interfaceApi2 = AstProxyApi(
       name: 'Api3',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'Api5'},
+      interfaces: <TypeDeclaration>{
+        TypeDeclaration(
+          baseName: 'Api5',
+          isNullable: false,
+          associatedProxyApi: interfaceOfInterfaceApi2,
+        ),
+      },
     );
-    final AstProxyApi interfaceOfInterfaceApi = AstProxyApi(
-      name: 'Api4',
+    final AstProxyApi interfaceApi = AstProxyApi(
+      name: 'Api2',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
+      interfaces: <TypeDeclaration>{
+        TypeDeclaration(
+          baseName: 'Api4',
+          isNullable: false,
+          associatedProxyApi: interfaceOfInterfaceApi,
+        ),
+        TypeDeclaration(
+          baseName: 'Api5',
+          isNullable: false,
+          associatedProxyApi: interfaceOfInterfaceApi2,
+        ),
+      },
     );
-    final AstProxyApi interfaceOfInterfaceApi2 = AstProxyApi(
-      name: 'Api5',
+    final AstProxyApi api = AstProxyApi(
+      name: 'Api',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
+      interfaces: <TypeDeclaration>{
+        TypeDeclaration(
+          baseName: 'Api2',
+          isNullable: false,
+          associatedProxyApi: interfaceApi,
+        ),
+        TypeDeclaration(
+          baseName: 'Api3',
+          isNullable: false,
+          associatedProxyApi: interfaceApi2,
+        ),
+      },
     );
 
-    final Set<AstProxyApi> allInterfaces = recursiveFindAllInterfacesApis(
-      api,
-      <AstProxyApi>[
-        api,
-        interfaceApi,
-        interfaceApi2,
-        interfaceOfInterfaceApi,
-        interfaceOfInterfaceApi2,
-      ],
-    );
+    final Set<AstProxyApi> allInterfaces = recursiveFindAllInterfaceApis(api);
 
     expect(
       allInterfaces,
@@ -475,25 +499,32 @@ void main() {
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'B'},
     );
     final AstProxyApi b = AstProxyApi(
       name: 'B',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'C'},
     );
     final AstProxyApi c = AstProxyApi(
       name: 'C',
       methods: <Method>[],
       constructors: <Constructor>[],
       fields: <ApiField>[],
-      interfacesNames: <String>{'A'},
     );
 
+    a.interfaces = <TypeDeclaration>{
+      TypeDeclaration(baseName: 'B', isNullable: false, associatedProxyApi: b),
+    };
+    b.interfaces = <TypeDeclaration>{
+      TypeDeclaration(baseName: 'C', isNullable: false, associatedProxyApi: c),
+    };
+    c.interfaces = <TypeDeclaration>{
+      TypeDeclaration(baseName: 'A', isNullable: false, associatedProxyApi: a),
+    };
+
     expect(
-      () => recursiveFindAllInterfacesApis(a, <AstProxyApi>[a, b, c]),
+      () => recursiveFindAllInterfaceApis(a),
       throwsArgumentError,
     );
   });

From 54c7ac2e65b45c7a8d85b6af2970ececdbda7dda Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Thu, 25 Jan 2024 17:40:50 -0500
Subject: [PATCH 16/32] add deps

---
 packages/pigeon/pubspec.yaml              | 2 ++
 script/configs/allowed_unpinned_deps.yaml | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index e077f7d81324..8ad64e843eee 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -10,7 +10,9 @@ environment:
 dependencies:
   analyzer: ">=5.13.0 <7.0.0"
   args: ^2.1.0
+  code_builder: ^4.10.0
   collection: ^1.15.0
+  dart_style: ^2.3.4
   meta: ^1.9.0
   path: ^1.8.0
   yaml: ^3.1.1
diff --git a/script/configs/allowed_unpinned_deps.yaml b/script/configs/allowed_unpinned_deps.yaml
index fe4c138b0a63..84ff94a1101b 100644
--- a/script/configs/allowed_unpinned_deps.yaml
+++ b/script/configs/allowed_unpinned_deps.yaml
@@ -25,9 +25,11 @@
 - build_config
 - build_runner
 - build_test
+- code_builder
 - collection
 - convert
 - crypto
+- dart_style
 - fake_async
 - ffi
 - gcloud

From d05bebffa4aeab25735015876e01f9b608cfaf71 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 26 Jan 2024 19:13:26 -0500
Subject: [PATCH 17/32] add proxyapi ast helper gen methods

---
 packages/pigeon/lib/dart/templates.dart  | 391 +++++++++++++
 packages/pigeon/lib/dart_generator.dart  | 711 ++++++++++++++++++++++-
 packages/pigeon/lib/generator_tools.dart |  48 +-
 3 files changed, 1135 insertions(+), 15 deletions(-)
 create mode 100644 packages/pigeon/lib/dart/templates.dart

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
new file mode 100644
index 000000000000..bcc152f13fa4
--- /dev/null
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -0,0 +1,391 @@
+import '../generator_tools.dart';
+
+/// Creates the `InstanceManager` with the passed string values.
+String instanceManagerTemplate({
+  required String proxyApiBaseClassName,
+  required List<String> allProxyApiNames,
+}) {
+  //const String proxyApiBaseClassName = '${classNamePrefix}ProxyApiBaseClass';
+
+  final Iterable<String> apiHandlerSetUps = allProxyApiNames.map(
+    (String name) {
+      return '$name.${classMemberNamePrefix}setUpMessageHandlers(${classMemberNamePrefix}instanceManager: instanceManager);';
+    },
+  );
+
+  return '''
+/// Maintains instances used to communicate with the native objects they
+/// represent.
+///
+/// Added instances are stored as weak references and their copies are stored
+/// as strong references to maintain access to their variables and callback
+/// methods. Both are stored with the same identifier.
+///
+/// When a weak referenced instance becomes inaccessible,
+/// [onWeakReferenceRemoved] is called with its associated identifier.
+///
+/// If an instance is retrieved and has the possibility to be used,
+/// (e.g. calling [getInstanceWithWeakReference]) a copy of the strong reference
+/// is added as a weak reference with the same identifier. This prevents a
+/// scenario where the weak referenced instance was released and then later
+/// returned by the host platform.
+class $instanceManagerClassName {
+  /// Constructs a [$instanceManagerClassName].
+  $instanceManagerClassName({required void Function(int) onWeakReferenceRemoved}) {
+    this.onWeakReferenceRemoved = (int identifier) {
+      _weakInstances.remove(identifier);
+      onWeakReferenceRemoved(identifier);
+    };
+    _finalizer = Finalizer<int>(this.onWeakReferenceRemoved);
+  }
+
+  // Identifiers are locked to a specific range to avoid collisions with objects
+  // created simultaneously by the host platform.
+  // Host uses identifiers >= 2^16 and Dart is expected to use values n where,
+  // 0 <= n < 2^16.
+  static const int _maxDartCreatedIdentifier = 65536;
+
+  /// The default [$instanceManagerClassName] used by ProxyApis.
+  ///
+  /// On creation, this manager makes a call to clear the native
+  /// InstanceManager. This is to prevent identifier conflicts after a host
+  /// restart.
+  static final $instanceManagerClassName instance = _initInstance();
+
+  // Expando is used because it doesn't prevent its keys from becoming
+  // inaccessible. This allows the manager to efficiently retrieve an identifier
+  // of an instance without holding a strong reference to that instance.
+  //
+  // It also doesn't use `==` to search for identifiers, which would lead to an
+  // infinite loop when comparing an object to its copy. (i.e. which was caused
+  // by calling instanceManager.getIdentifier() inside of `==` while this was a
+  // HashMap).
+  final Expando<int> _identifiers = Expando<int>();
+  final Map<int, WeakReference<$proxyApiBaseClassName>> _weakInstances =
+      <int, WeakReference<$proxyApiBaseClassName>>{};
+  final Map<int, $proxyApiBaseClassName> _strongInstances = <int, $proxyApiBaseClassName>{};
+  late final Finalizer<int> _finalizer;
+  int _nextIdentifier = 0;
+
+  /// Called when a weak referenced instance is removed by [removeWeakReference]
+  /// or becomes inaccessible.
+  late final void Function(int) onWeakReferenceRemoved;
+
+  static $instanceManagerClassName _initInstance() {
+    WidgetsFlutterBinding.ensureInitialized();
+    final _${instanceManagerClassName}Api api = _${instanceManagerClassName}Api();
+    // Clears the native `$instanceManagerClassName` on the initial use of the Dart one.
+    api.clear();
+    final $instanceManagerClassName instanceManager = $instanceManagerClassName(
+      onWeakReferenceRemoved: (int identifier) {
+        api.removeStrongReference(identifier);
+      },
+    );
+    _${instanceManagerClassName}Api.setUpMessageHandlers(instanceManager: instanceManager);
+    ${apiHandlerSetUps.join('\n\t\t')}
+    return instanceManager;
+  }
+
+  /// Adds a new instance that was instantiated by Dart.
+  ///
+  /// In other words, Dart wants to add a new instance that will represent
+  /// an object that will be instantiated on the host platform.
+  ///
+  /// Throws assertion error if the instance has already been added.
+  ///
+  /// Returns the randomly generated id of the [instance] added.
+  int addDartCreatedInstance($proxyApiBaseClassName instance) {
+    final int identifier = _nextUniqueIdentifier();
+    _addInstanceWithIdentifier(instance, identifier);
+    return identifier;
+  }
+
+  /// Removes the instance, if present, and call [onWeakReferenceRemoved] with
+  /// its identifier.
+  ///
+  /// Returns the identifier associated with the removed instance. Otherwise,
+  /// `null` if the instance was not found in this manager.
+  ///
+  /// This does not remove the strong referenced instance associated with
+  /// [instance]. This can be done with [remove].
+  int? removeWeakReference($proxyApiBaseClassName instance) {
+    final int? identifier = getIdentifier(instance);
+    if (identifier == null) {
+      return null;
+    }
+
+    _identifiers[instance] = null;
+    _finalizer.detach(instance);
+    onWeakReferenceRemoved(identifier);
+
+    return identifier;
+  }
+
+  /// Removes [identifier] and its associated strongly referenced instance, if
+  /// present, from the manager.
+  ///
+  /// Returns the strong referenced instance associated with [identifier] before
+  /// it was removed. Returns `null` if [identifier] was not associated with
+  /// any strong reference.
+  ///
+  /// This does not remove the weak referenced instance associated with
+  /// [identifier]. This can be done with [removeWeakReference].
+  T? remove<T extends $proxyApiBaseClassName>(int identifier) {
+    return _strongInstances.remove(identifier) as T?;
+  }
+
+  /// Retrieves the instance associated with identifier.
+  ///
+  /// The value returned is chosen from the following order:
+  ///
+  /// 1. A weakly referenced instance associated with identifier.
+  /// 2. If the only instance associated with identifier is a strongly
+  /// referenced instance, a copy of the instance is added as a weak reference
+  /// with the same identifier. Returning the newly created copy.
+  /// 3. If no instance is associated with identifier, returns null.
+  ///
+  /// This method also expects the host `InstanceManager` to have a strong
+  /// reference to the instance the identifier is associated with.
+  T? getInstanceWithWeakReference<T extends $proxyApiBaseClassName>(int identifier) {
+    final $proxyApiBaseClassName? weakInstance = _weakInstances[identifier]?.target;
+
+    if (weakInstance == null) {
+      final $proxyApiBaseClassName? strongInstance = _strongInstances[identifier];
+      if (strongInstance != null) {
+        final $proxyApiBaseClassName copy = strongInstance.${classMemberNamePrefix}copy();
+        _identifiers[copy] = identifier;
+        _weakInstances[identifier] = WeakReference<$proxyApiBaseClassName>(copy);
+        _finalizer.attach(copy, identifier, detach: copy);
+        return copy as T;
+      }
+      return strongInstance as T?;
+    }
+
+    return weakInstance as T;
+  }
+
+  /// Retrieves the identifier associated with instance.
+  int? getIdentifier($proxyApiBaseClassName instance) {
+    return _identifiers[instance];
+  }
+
+  /// Adds a new instance that was instantiated by the host platform.
+  ///
+  /// In other words, the host platform wants to add a new instance that
+  /// represents an object on the host platform. Stored with [identifier].
+  ///
+  /// Throws assertion error if the instance or its identifier has already been
+  /// added.
+  ///
+  /// Returns unique identifier of the [instance] added.
+  void addHostCreatedInstance($proxyApiBaseClassName instance, int identifier) {
+    _addInstanceWithIdentifier(instance, identifier);
+  }
+
+  void _addInstanceWithIdentifier($proxyApiBaseClassName instance, int identifier) {
+    assert(!containsIdentifier(identifier));
+    assert(getIdentifier(instance) == null);
+    assert(identifier >= 0);
+
+    _identifiers[instance] = identifier;
+    _weakInstances[identifier] = WeakReference<$proxyApiBaseClassName>(instance);
+    _finalizer.attach(instance, identifier, detach: instance);
+
+    final $proxyApiBaseClassName copy = instance.${classMemberNamePrefix}copy();
+    _identifiers[copy] = identifier;
+    _strongInstances[identifier] = copy;
+  }
+
+  /// Whether this manager contains the given [identifier].
+  bool containsIdentifier(int identifier) {
+    return _weakInstances.containsKey(identifier) ||
+        _strongInstances.containsKey(identifier);
+  }
+
+  int _nextUniqueIdentifier() {
+    late int identifier;
+    do {
+      identifier = _nextIdentifier;
+      _nextIdentifier = (_nextIdentifier + 1) % _maxDartCreatedIdentifier;
+    } while (containsIdentifier(identifier));
+    return identifier;
+  }
+}
+''';
+}
+
+/// Creates the `InstanceManagerApi` with the passed string values.
+String instanceManagerApiTemplate({
+  required String dartPackageName,
+  required String pigeonChannelCodecVarName,
+}) {
+  const String apiName = '${instanceManagerClassName}Api';
+
+  final String removeStrongReferenceName = makeChannelNameWithStrings(
+    apiName: apiName,
+    methodName: 'removeStrongReference',
+    dartPackageName: dartPackageName,
+  );
+
+  final String clearName = makeChannelNameWithStrings(
+    apiName: apiName,
+    methodName: 'clear',
+    dartPackageName: dartPackageName,
+  );
+
+  return '''
+/// Generated API for managing the Dart and native `$instanceManagerClassName`s.
+class _$apiName {
+  /// Constructor for [_$apiName ].
+  _$apiName({BinaryMessenger? binaryMessenger})
+      : _binaryMessenger = binaryMessenger;
+
+  final BinaryMessenger? _binaryMessenger;
+  
+  static const MessageCodec<Object?> $pigeonChannelCodecVarName =
+     StandardMessageCodec();
+
+  static void setUpMessageHandlers({
+    BinaryMessenger? binaryMessenger,
+    $instanceManagerClassName? instanceManager,
+  }) {
+    const String channelName =
+        r'$removeStrongReferenceName';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      $pigeonChannelCodecVarName,
+      binaryMessenger: binaryMessenger,
+    );
+    channel.setMessageHandler((Object? message) async {
+      assert(
+        message != null,
+        'Argument for \$channelName was null.',
+      );
+      final int? identifier = message as int?;
+      assert(
+        identifier != null,
+        r'Argument for \$channelName, expected non-null int.',
+      );
+      (instanceManager ?? $instanceManagerClassName.instance).remove(identifier!);
+      return;
+    });
+  }
+
+  Future<void> removeStrongReference(int identifier) async {
+    const String channelName =
+        r'$removeStrongReferenceName';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      $pigeonChannelCodecVarName,
+      binaryMessenger: _binaryMessenger,
+    );
+    final List<Object?>? replyList =
+        await channel.send(identifier) as List<Object?>?;
+    if (replyList == null) {
+      throw _createConnectionError(channelName);
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Clear the native `$instanceManagerClassName`.
+  ///
+  /// This is typically called after a hot restart.
+  Future<void> clear() async {
+    const String channelName =
+        r'$clearName';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      $pigeonChannelCodecVarName,
+      binaryMessenger: _binaryMessenger,
+    );
+    final List<Object?>? replyList = await channel.send(null) as List<Object?>?;
+    if (replyList == null) {
+      throw _createConnectionError(channelName);
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+}''';
+}
+
+const String proxyApiBaseClass = '''
+/// An immutable object that serves as the base class for all ProxyApis and
+/// can provide functional copies of itself.
+///
+/// All implementers are expected to be [immutable] as defined by the annotation
+/// and override [${classMemberNamePrefix}copy] returning an instance of itself.
+@immutable
+abstract class $_proxyApiBaseClassName {
+  /// Construct a [$_proxyApiBaseClassName].
+  $_proxyApiBaseClassName({
+    this.$_proxyApiBaseClassMessengerVarName,
+    $instanceManagerClassName? $_proxyApiBaseClassInstanceManagerVarName,
+  }) : $_proxyApiBaseClassInstanceManagerVarName =
+            $_proxyApiBaseClassInstanceManagerVarName ?? $instanceManagerClassName.instance;
+
+  /// Sends and receives binary data across the Flutter platform barrier.
+  ///
+  /// If it is null, the default BinaryMessenger will be used, which routes to
+  /// the host platform.
+  final BinaryMessenger? $_proxyApiBaseClassMessengerVarName;
+
+  /// Maintains instances stored to communicate with native language objects.
+  final $instanceManagerClassName $_proxyApiBaseClassInstanceManagerVarName;
+
+  /// Instantiates and returns a functionally identical object to oneself.
+  ///
+  /// Outside of tests, this method should only ever be called by
+  /// [$instanceManagerClassName].
+  ///
+  /// Subclasses should always override their parent's implementation of this
+  /// method.
+  @protected
+  $_proxyApiBaseClassName ${classMemberNamePrefix}copy();
+}
+''';
+
+const String proxyApiCodec = '''
+class $_proxyApiCodecName extends StandardMessageCodec {
+ const $_proxyApiCodecName(this.instanceManager);
+ final $instanceManagerClassName instanceManager;
+ @override
+ void writeValue(WriteBuffer buffer, Object? value) {
+   if (value is $_proxyApiBaseClassName) {
+     buffer.putUint8(128);
+     writeValue(buffer, instanceManager.getIdentifier(value));
+   } else {
+     super.writeValue(buffer, value);
+   }
+ }
+ @override
+ Object? readValueOfType(int type, ReadBuffer buffer) {
+   switch (type) {
+     case 128:
+       return instanceManager
+           .getInstanceWithWeakReference(readValue(buffer)! as int);
+     default:
+       return super.readValueOfType(type, buffer);
+   }
+ }
+}
+''';
+
+const String _proxyApiBaseClassName = '${classNamePrefix}ProxyApiBaseClass';
+const String _proxyApiBaseClassMessengerVarName =
+    '${classMemberNamePrefix}binaryMessenger';
+const String _proxyApiBaseClassInstanceManagerVarName =
+    '${classMemberNamePrefix}instanceManager';
+const String _proxyApiCodecName = '_${classNamePrefix}ProxyApiBaseCodec';
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 8cdea012554b..c3dce2ce2ca2 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:code_builder/code_builder.dart' as cb;
+import 'package:collection/collection.dart' as collection;
 import 'package:path/path.dart' as path;
 
 import 'ast.dart';
@@ -18,6 +20,10 @@ const String _docCommentPrefix = '///';
 /// user defined parameters.
 const String _varNamePrefix = '__pigeon_';
 
+/// Name of the `InstanceManager` variable for a ProxyApi class;
+const String _instanceManagerVarName =
+    '${classMemberNamePrefix}instanceManager';
+
 /// Name of field used for host API codec.
 const String _pigeonChannelCodec = 'pigeonChannelCodec';
 
@@ -94,7 +100,10 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
     indent.writeln('// ${getGeneratedCodeWarning()}');
     indent.writeln('// $seeAlsoWarning');
     indent.writeln(
-      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers',
+      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, '
+      'avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, '
+      'omit_local_variable_types, unused_shown_name, unnecessary_import, '
+      'no_leading_underscores_for_local_identifiers, camel_case_types',
     );
     indent.newln();
   }
@@ -111,9 +120,16 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
       "import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;",
     );
     indent.newln();
+
+    final bool hasProxyApi = root.apis.any((Api api) => api is AstProxyApi);
     indent.writeln(
-        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;");
+        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer${hasProxyApi ? ' immutable, protected' : ''};");
     indent.writeln("import 'package:flutter/services.dart';");
+    if (hasProxyApi) {
+      indent.writeln(
+        "import 'package:flutter/widgets.dart' show WidgetsFlutterBinding;",
+      );
+    }
   }
 
   @override
@@ -434,6 +450,686 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     });
   }
 
+  Iterable<cb.Constructor> _proxyApiConstructors(
+    Iterable<Constructor> constructors, {
+    required String apiName,
+    required String dartPackageName,
+    required String codecName,
+    required String codecInstanceName,
+    required AstProxyApi? superClassApi,
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<Method> superClassFlutterMethods,
+    required Iterable<Method> interfacesMethods,
+    required Iterable<Method> flutterMethods,
+  }) {
+    final cb.Parameter binaryMessengerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}binaryMessenger'
+        ..named = true
+        ..toSuper = true,
+    );
+    final cb.Parameter instanceManagerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = _instanceManagerVarName
+        ..named = true
+        ..toSuper = true,
+    );
+    return <cb.Constructor>[
+      // All constructors for this api defined in the pigeon file.
+      ...constructors.map(
+        (Constructor constructor) => cb.Constructor(
+          (cb.ConstructorBuilder builder) {
+            final String channelName = makeChannelNameWithStrings(
+              apiName: apiName,
+              methodName: constructor.name.isNotEmpty
+                  ? constructor.name
+                  : '${classMemberNamePrefix}defaultConstructor',
+              dartPackageName: dartPackageName,
+            );
+            builder
+              ..name = constructor.name.isNotEmpty ? constructor.name : null
+              ..docs.addAll(asDocumentationComments(
+                constructor.documentationComments,
+                _docCommentSpec,
+              ))
+              ..optionalParameters.addAll(
+                <cb.Parameter>[
+                  binaryMessengerParameter,
+                  instanceManagerParameter,
+                  for (final ApiField field in unattachedFields)
+                    cb.Parameter(
+                      (cb.ParameterBuilder builder) => builder
+                        ..name = field.name
+                        ..named = true
+                        ..toThis = true
+                        ..required = !field.type.isNullable,
+                    ),
+                  for (final Method method in superClassFlutterMethods
+                      .followedBy(interfacesMethods)
+                      .followedBy(flutterMethods))
+                    cb.Parameter(
+                      (cb.ParameterBuilder builder) => builder
+                        ..name = method.name
+                        ..named = true
+                        ..toSuper = true
+                        ..required = method.isRequired,
+                    ),
+                  ...constructor.parameters.mapIndexed(
+                    (int index, NamedType parameter) => cb.Parameter(
+                      (cb.ParameterBuilder builder) => builder
+                        ..name = _getParameterName(index, parameter)
+                        ..type = _refer(parameter.type)
+                        ..named = true
+                        ..required = !parameter.type.isNullable,
+                    ),
+                  )
+                ],
+              )
+              ..initializers.addAll(
+                <cb.Code>[
+                  if (superClassApi != null)
+                    const cb.Code('super.${classMemberNamePrefix}detached()')
+                ],
+              )
+              ..body = cb.Block(
+                (cb.BlockBuilder builder) {
+                  final StringBuffer messageCallSink = StringBuffer();
+                  _writeHostMethodMessageCall(
+                    Indent(messageCallSink),
+                    channelName: channelName,
+                    parameters: <Parameter>[
+                      Parameter(
+                        name: '${_varNamePrefix}instanceIdentifier',
+                        type: const TypeDeclaration(
+                          baseName: 'int',
+                          isNullable: false,
+                        ),
+                      ),
+                      ...unattachedFields.map(
+                        (ApiField field) => Parameter(
+                          name: field.name,
+                          type: field.type,
+                        ),
+                      ),
+                      ...constructor.parameters,
+                    ],
+                    returnType: const TypeDeclaration.voidDeclaration(),
+                  );
+                  builder.statements.addAll(<cb.Code>[
+                    const cb.Code(
+                      'final int ${_varNamePrefix}instanceIdentifier = $_instanceManagerVarName.addDartCreatedInstance(this);',
+                    ),
+                    cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                        '    $codecInstanceName;'),
+                    cb.Code(
+                      'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${binaryMessengerParameter.name};',
+                    ),
+                    const cb.Code('() async {'),
+                    cb.Code(messageCallSink.toString()),
+                    const cb.Code('}();'),
+                  ]);
+                },
+              );
+          },
+        ),
+      ),
+      // The detached constructor present for every ProxyApi. This constructor
+      // doesn't include a host method call to create a new native class
+      // instance. It is mainly used when the native side once to create a Dart
+      // instance and when the `InstanceManager` wants to create a copy for
+      // garbage collection.
+      cb.Constructor(
+        (cb.ConstructorBuilder builder) => builder
+          ..name = '${classMemberNamePrefix}detached'
+          ..docs.addAll(<String>[
+            '/// Constructs $apiName without creating the associated native object.',
+            '///',
+            '/// This should only be used by subclasses created by this library or to',
+            '/// create copies for an [$instanceManagerClassName].',
+          ])
+          ..optionalParameters.addAll(<cb.Parameter>[
+            binaryMessengerParameter,
+            instanceManagerParameter,
+            for (final ApiField field in unattachedFields)
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = field.name
+                  ..named = true
+                  ..toThis = true
+                  ..required = !field.type.isNullable,
+              ),
+            for (final Method method in superClassFlutterMethods
+                .followedBy(interfacesMethods)
+                .followedBy(flutterMethods))
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = method.name
+                  ..named = true
+                  ..toSuper = true
+                  ..required = method.isRequired,
+              ),
+          ])
+          ..initializers.addAll(<cb.Code>[
+            if (superClassApi != null)
+              const cb.Code('super.${classMemberNamePrefix}detached()'),
+          ]),
+      ),
+    ];
+  }
+
+  Iterable<cb.Field> _proxyApiFields({
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<ApiField> attachedFields,
+    required String apiName,
+    required String dartPackageName,
+    required String codecInstanceName,
+    required String codecName,
+    required Iterable<AstProxyApi> interfacesApis,
+    required Iterable<Method> flutterMethods,
+    required bool referencesCodecInstance,
+  }) {
+    return <cb.Field>[
+      if (referencesCodecInstance)
+        cb.Field(
+          (cb.FieldBuilder builder) => builder
+            ..name = codecInstanceName
+            ..type = cb.refer(codecName)
+            ..late = true
+            ..modifier = cb.FieldModifier.final$
+            ..assignment = cb.Code('$codecName($_instanceManagerVarName)'),
+        ),
+      for (final ApiField field in unattachedFields)
+        cb.Field(
+          (cb.FieldBuilder builder) => builder
+            ..name = field.name
+            ..type = cb.refer(_addGenericTypesNullable(field.type))
+            ..modifier = cb.FieldModifier.final$
+            ..docs.addAll(asDocumentationComments(
+              field.documentationComments,
+              _docCommentSpec,
+            )),
+        ),
+      for (final Method method in flutterMethods)
+        cb.Field(
+          (cb.FieldBuilder builder) => builder
+            ..name = method.name
+            ..modifier = cb.FieldModifier.final$
+            ..docs.addAll(asDocumentationComments(
+              <String>[
+                ...method.documentationComments,
+                ...<String>[
+                  if (method.documentationComments.isNotEmpty) '',
+                  'Dart:',
+                  'For the associated Native object to be automatically garbage collected,',
+                  "it is required that the implementation of this `Function` doesn't have a",
+                  'strong reference to the encapsulating class instance. When this `Function`',
+                  'references a non-local variable, it is strongly recommended to access it',
+                  'from a `WeakReference`:',
+                  '',
+                  '```dart',
+                  'final WeakReference weakMyVariable = WeakReference(myVariable);',
+                  'final $apiName instance = $apiName(',
+                  '  ${method.name}: ($apiName ${classMemberNamePrefix}instance, ...) {',
+                  '    print(weakMyVariable?.target);',
+                  '  },',
+                  ');',
+                  '```',
+                  '',
+                  'Alternatively, `$instanceManagerClassName.removeWeakReference` can be used to',
+                  'release the associated Native object manually.',
+                ],
+              ],
+              _docCommentSpec,
+            ))
+            ..type = cb.FunctionType(
+              (cb.FunctionTypeBuilder builder) => builder
+                ..returnType = _refer(
+                  method.returnType,
+                  asFuture: method.isAsynchronous,
+                )
+                ..isNullable = !method.isRequired
+                ..requiredParameters.addAll(<cb.Reference>[
+                  cb.refer('$apiName ${classMemberNamePrefix}instance'),
+                  ...method.parameters.mapIndexed(
+                    (int index, NamedType parameter) {
+                      return cb.refer(
+                        '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                      );
+                    },
+                  ),
+                ]),
+            ),
+        ),
+      for (final AstProxyApi proxyApi in interfacesApis)
+        for (final Method method in proxyApi.methods)
+          cb.Field(
+            (cb.FieldBuilder builder) => builder
+              ..name = method.name
+              ..modifier = cb.FieldModifier.final$
+              ..annotations.add(cb.refer('override'))
+              ..docs.addAll(asDocumentationComments(
+                method.documentationComments,
+                _docCommentSpec,
+              ))
+              ..type = cb.FunctionType(
+                (cb.FunctionTypeBuilder builder) => builder
+                  ..returnType = _refer(
+                    method.returnType,
+                    asFuture: method.isAsynchronous,
+                  )
+                  ..isNullable = !method.isRequired
+                  ..requiredParameters.addAll(<cb.Reference>[
+                    cb.refer(
+                      '${proxyApi.name} ${classMemberNamePrefix}instance',
+                    ),
+                    ...method.parameters.mapIndexed(
+                      (int index, NamedType parameter) {
+                        return cb.refer(
+                          '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                        );
+                      },
+                    ),
+                  ]),
+              ),
+          ),
+      for (final ApiField field in attachedFields)
+        cb.Field(
+          (cb.FieldBuilder builder) => builder
+            ..name = field.name
+            ..type = cb.refer(_addGenericTypesNullable(field.type))
+            ..modifier = cb.FieldModifier.final$
+            ..static = field.isStatic
+            ..late = !field.isStatic
+            ..docs.addAll(asDocumentationComments(
+              field.documentationComments,
+              _docCommentSpec,
+            ))
+            ..assignment = cb.Code('$_varNamePrefix${field.name}()'),
+        ),
+    ];
+  }
+
+  Iterable<cb.Method> _proxyApiMethods({
+    required Iterable<Method> hostMethods,
+    required Iterable<Method> flutterMethods,
+    required Iterable<Method> superClassFlutterMethods,
+    required String apiName,
+    required String dartPackageName,
+    required String codecInstanceName,
+    required String codecName,
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<ApiField> attachedFields,
+    required Iterable<AstProxyApi> interfacesApis,
+    required bool hasCallbackConstructor,
+  }) {
+    return <cb.Method>[
+      // Flutter methods message handler `*setUpMessageHandlers()`
+      cb.Method.returnsVoid(
+        (cb.MethodBuilder builder) => builder
+          ..name = '${classMemberNamePrefix}setUpMessageHandlers'
+          ..returns = cb.refer('void')
+          ..static = true
+          ..optionalParameters.addAll(<cb.Parameter>[
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = '${classMemberNamePrefix}clearHandlers'
+                ..type = cb.refer('bool')
+                ..named = true
+                ..defaultTo = const cb.Code('false'),
+            ),
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = '${classMemberNamePrefix}binaryMessenger'
+                ..named = true
+                ..type = cb.refer('BinaryMessenger?'),
+            ),
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = _instanceManagerVarName
+                ..named = true
+                ..type = cb.refer('$instanceManagerClassName?'),
+            ),
+            if (hasCallbackConstructor)
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = '${classMemberNamePrefix}newInstance'
+                  ..named = true
+                  ..type = cb.FunctionType(
+                    (cb.FunctionTypeBuilder builder) => builder
+                      ..returnType = cb.refer(apiName)
+                      ..isNullable = true
+                      ..requiredParameters.addAll(
+                        unattachedFields.mapIndexed(
+                          (int index, ApiField field) {
+                            return cb.refer(
+                              '${_addGenericTypesNullable(field.type)} ${_getParameterName(index, field)}',
+                            );
+                          },
+                        ),
+                      ),
+                  ),
+              ),
+            for (final Method method in flutterMethods)
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = method.name
+                  ..type = cb.FunctionType(
+                    (cb.FunctionTypeBuilder builder) => builder
+                      ..returnType = _refer(
+                        method.returnType,
+                        asFuture: method.isAsynchronous,
+                      )
+                      ..isNullable = true
+                      ..requiredParameters.addAll(<cb.Reference>[
+                        cb.refer('$apiName ${classMemberNamePrefix}instance'),
+                        ...method.parameters.mapIndexed(
+                          (int index, NamedType parameter) {
+                            return cb.refer(
+                              '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                            );
+                          },
+                        ),
+                      ]),
+                  ),
+              ),
+          ])
+          ..body = cb.Block.of(<cb.Code>[
+            cb.Code(
+              'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
+            ),
+            const cb.Code(
+              'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+            ),
+            if (hasCallbackConstructor)
+              ...cb.Block((cb.BlockBuilder builder) {
+                final StringBuffer messageHandlerSink = StringBuffer();
+                const String methodName = '${classMemberNamePrefix}newInstance';
+                _writeFlutterMethodMessageHandler(
+                  Indent(messageHandlerSink),
+                  name: methodName,
+                  parameters: <Parameter>[
+                    Parameter(
+                      name: '${classMemberNamePrefix}instanceIdentifier',
+                      type: const TypeDeclaration(
+                        baseName: 'int',
+                        isNullable: false,
+                      ),
+                    ),
+                    ...unattachedFields.map(
+                      (ApiField field) =>
+                          Parameter(name: field.name, type: field.type),
+                    ),
+                  ],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                  channelName: makeChannelNameWithStrings(
+                    apiName: apiName,
+                    methodName: methodName,
+                    dartPackageName: dartPackageName,
+                  ),
+                  isMockHandler: false,
+                  isAsynchronous: false,
+                  nullHandlerExpression:
+                      '${classMemberNamePrefix}clearHandlers',
+                  onCreateApiCall: (
+                    String methodName,
+                    Iterable<Parameter> parameters,
+                    Iterable<String> safeArgumentNames,
+                  ) {
+                    final String argsAsNamedParams = map2(
+                      parameters,
+                      safeArgumentNames,
+                      (Parameter parameter, String safeArgName) {
+                        return '${parameter.name}: $safeArgName,\n';
+                      },
+                    ).skip(1).join();
+                    return '($_instanceManagerVarName ?? $instanceManagerClassName.instance)\n'
+                        '    .addHostCreatedInstance(\n'
+                        '  $methodName?.call(${safeArgumentNames.skip(1).join(',')}) ??\n'
+                        '      $apiName.${classMemberNamePrefix}detached('
+                        '        ${classMemberNamePrefix}binaryMessenger: ${classMemberNamePrefix}binaryMessenger,\n'
+                        '        $_instanceManagerVarName: $_instanceManagerVarName,\n'
+                        '        $argsAsNamedParams\n'
+                        '      ),\n'
+                        '  ${safeArgumentNames.first},\n'
+                        ')';
+                  },
+                );
+                builder.statements.add(cb.Code(messageHandlerSink.toString()));
+              }).statements,
+            for (final Method method in flutterMethods)
+              ...cb.Block((cb.BlockBuilder builder) {
+                final StringBuffer messageHandlerSink = StringBuffer();
+                _writeFlutterMethodMessageHandler(
+                  Indent(messageHandlerSink),
+                  name: method.name,
+                  parameters: <Parameter>[
+                    Parameter(
+                      name: '${classMemberNamePrefix}instance',
+                      type: TypeDeclaration(
+                        baseName: apiName,
+                        isNullable: false,
+                      ),
+                    ),
+                    ...method.parameters,
+                  ],
+                  returnType: TypeDeclaration(
+                    baseName: method.returnType.baseName,
+                    isNullable:
+                        !method.isRequired || method.returnType.isNullable,
+                    typeArguments: method.returnType.typeArguments,
+                    associatedEnum: method.returnType.associatedEnum,
+                    associatedClass: method.returnType.associatedClass,
+                    associatedProxyApi: method.returnType.associatedProxyApi,
+                  ),
+                  channelName: makeChannelNameWithStrings(
+                    apiName: apiName,
+                    methodName: method.name,
+                    dartPackageName: dartPackageName,
+                  ),
+                  isMockHandler: false,
+                  isAsynchronous: method.isAsynchronous,
+                  nullHandlerExpression:
+                      '${classMemberNamePrefix}clearHandlers',
+                  onCreateApiCall: (
+                    String methodName,
+                    Iterable<Parameter> parameters,
+                    Iterable<String> safeArgumentNames,
+                  ) {
+                    final String nullability = method.isRequired ? '' : '?';
+                    return '($methodName ?? ${safeArgumentNames.first}.$methodName)$nullability.call(${safeArgumentNames.join(',')})';
+                  },
+                );
+                builder.statements.add(cb.Code(messageHandlerSink.toString()));
+              }).statements,
+          ]),
+      ),
+      for (final ApiField field in attachedFields)
+        cb.Method(
+          (cb.MethodBuilder builder) {
+            final String type = _addGenericTypesNullable(field.type);
+            const String instanceName = '${_varNamePrefix}instance';
+            const String identifierInstanceName =
+                '${_varNamePrefix}instanceIdentifier';
+            builder
+              ..name = '$_varNamePrefix${field.name}'
+              ..static = field.isStatic
+              ..returns = cb.refer(type)
+              ..body = cb.Block(
+                (cb.BlockBuilder builder) {
+                  final StringBuffer messageCallSink = StringBuffer();
+                  _writeHostMethodMessageCall(
+                    Indent(messageCallSink),
+                    channelName: makeChannelNameWithStrings(
+                      apiName: apiName,
+                      methodName: field.name,
+                      dartPackageName: dartPackageName,
+                    ),
+                    parameters: <Parameter>[
+                      if (!field.isStatic)
+                        Parameter(
+                          name: 'this',
+                          type: TypeDeclaration(
+                            baseName: apiName,
+                            isNullable: false,
+                          ),
+                        ),
+                      Parameter(
+                        name: identifierInstanceName,
+                        type: const TypeDeclaration(
+                          baseName: 'int',
+                          isNullable: false,
+                        ),
+                      ),
+                    ],
+                    returnType: const TypeDeclaration.voidDeclaration(),
+                  );
+                  builder.statements.addAll(<cb.Code>[
+                    if (!field.isStatic) ...<cb.Code>[
+                      cb.Code(
+                        'final $type $instanceName = $type.${classMemberNamePrefix}detached(\n'
+                        '  pigeon_binaryMessenger: pigeon_binaryMessenger,\n'
+                        '  pigeon_instanceManager: pigeon_instanceManager,\n'
+                        ');',
+                      ),
+                      cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                          '    $codecInstanceName;'),
+                      const cb.Code(
+                        'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+                      ),
+                      const cb.Code(
+                        'final int $identifierInstanceName = $_instanceManagerVarName.addDartCreatedInstance($instanceName);',
+                      ),
+                    ] else ...<cb.Code>[
+                      cb.Code(
+                        'final $type $instanceName = $type.${classMemberNamePrefix}detached();',
+                      ),
+                      cb.Code(
+                        'final $codecName $_pigeonChannelCodec = $codecName($instanceManagerClassName.instance);',
+                      ),
+                      const cb.Code(
+                        'final BinaryMessenger ${_varNamePrefix}binaryMessenger = ServicesBinding.instance.defaultBinaryMessenger;',
+                      ),
+                      const cb.Code(
+                        'final int $identifierInstanceName = $instanceManagerClassName.instance.addDartCreatedInstance($instanceName);',
+                      ),
+                    ],
+                    const cb.Code('() async {'),
+                    cb.Code(messageCallSink.toString()),
+                    const cb.Code('}();'),
+                    const cb.Code('return $instanceName;'),
+                  ]);
+                },
+              );
+          },
+        ),
+      for (final Method method in hostMethods)
+        cb.Method(
+          (cb.MethodBuilder builder) => builder
+            ..name = method.name
+            ..static = method.isStatic
+            ..modifier = cb.MethodModifier.async
+            ..docs.addAll(asDocumentationComments(
+              method.documentationComments,
+              _docCommentSpec,
+            ))
+            ..returns = _refer(method.returnType, asFuture: true)
+            ..requiredParameters.addAll(
+              method.parameters.mapIndexed(
+                (int index, NamedType parameter) => cb.Parameter(
+                  (cb.ParameterBuilder builder) => builder
+                    ..name = _getParameterName(index, parameter)
+                    ..type = cb.refer(
+                      _addGenericTypesNullable(parameter.type),
+                    ),
+                ),
+              ),
+            )
+            ..optionalParameters.addAll(<cb.Parameter>[
+              if (method.isStatic) ...<cb.Parameter>[
+                cb.Parameter(
+                  (cb.ParameterBuilder builder) => builder
+                    ..name = '${classMemberNamePrefix}binaryMessenger'
+                    ..type = cb.refer('BinaryMessenger?')
+                    ..named = true,
+                ),
+                cb.Parameter(
+                  (cb.ParameterBuilder builder) => builder
+                    ..name = _instanceManagerVarName
+                    ..type = cb.refer('$instanceManagerClassName?'),
+                ),
+              ],
+            ])
+            ..body = cb.Block(
+              (cb.BlockBuilder builder) {
+                final StringBuffer messageCallSink = StringBuffer();
+                _writeHostMethodMessageCall(
+                  Indent(messageCallSink),
+                  channelName: makeChannelNameWithStrings(
+                    apiName: apiName,
+                    methodName: method.name,
+                    dartPackageName: dartPackageName,
+                  ),
+                  parameters: <Parameter>[
+                    if (!method.isStatic)
+                      Parameter(
+                        name: 'this',
+                        type: TypeDeclaration(
+                          baseName: apiName,
+                          isNullable: false,
+                        ),
+                      ),
+                    ...method.parameters,
+                  ],
+                  returnType: method.returnType,
+                );
+                builder.statements.addAll(<cb.Code>[
+                  if (!method.isStatic)
+                    cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                        '    $codecInstanceName;')
+                  else
+                    cb.Code(
+                      'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
+                    ),
+                  const cb.Code(
+                    'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+                  ),
+                  cb.Code(messageCallSink.toString()),
+                ]);
+              },
+            ),
+        ),
+      cb.Method(
+        (cb.MethodBuilder builder) => builder
+          ..name = '${classMemberNamePrefix}copy'
+          ..returns = cb.refer(apiName)
+          ..annotations.add(cb.refer('override'))
+          ..body = cb.Block.of(<cb.Code>[
+            cb
+                .refer('$apiName.${classMemberNamePrefix}detached')
+                .call(
+                  <cb.Expression>[],
+                  <String, cb.Expression>{
+                    '${classMemberNamePrefix}binaryMessenger':
+                        cb.refer('${classMemberNamePrefix}binaryMessenger'),
+                    _instanceManagerVarName: cb.refer(_instanceManagerVarName),
+                    for (final ApiField field in unattachedFields)
+                      field.name: cb.refer(field.name),
+                    for (final Method method in superClassFlutterMethods)
+                      method.name: cb.refer(method.name),
+                    for (final AstProxyApi proxyApi in interfacesApis)
+                      for (final Method method in proxyApi.methods)
+                        method.name: cb.refer(method.name),
+                    for (final Method method in flutterMethods)
+                      method.name: cb.refer(method.name),
+                  },
+                )
+                .returned
+                .statement,
+          ]),
+      ),
+    ];
+  }
+
   /// Generates Dart source code for test support libraries based on the given AST
   /// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
   /// path of the generated dart code to be tested. [testOutPath] is where the
@@ -678,7 +1374,8 @@ if (${_varNamePrefix}replyList == null) {
     required bool isMockHandler,
     required bool isAsynchronous,
     String nullHandlerExpression = 'api == null',
-    String Function(String methodName, Iterable<String> safeArgumentNames)
+    String Function(String methodName, Iterable<Parameter> parameters,
+            Iterable<String> safeArgumentNames)
         onCreateApiCall = _createFlutterApiMethodCall,
   }) {
     indent.write('');
@@ -745,7 +1442,7 @@ if (${_varNamePrefix}replyList == null) {
               final String name = _getSafeArgumentName(index, field);
               return '${field.isNamed ? '${field.name}: ' : ''}$name${field.type.isNullable ? '' : '!'}';
             });
-            call = onCreateApiCall(name, argNames);
+            call = onCreateApiCall(name, parameters, argNames);
           }
           indent.writeScoped('try {', '} ', () {
             if (returnType.isVoid) {
@@ -787,12 +1484,18 @@ if (${_varNamePrefix}replyList == null) {
 
   static String _createFlutterApiMethodCall(
     String methodName,
+    Iterable<Parameter> parameters,
     Iterable<String> safeArgumentNames,
   ) {
     return 'api.$methodName(${safeArgumentNames.join(', ')})';
   }
 }
 
+cb.Reference _refer(TypeDeclaration type, {bool asFuture = false}) {
+  final String symbol = _addGenericTypesNullable(type);
+  return cb.refer(asFuture ? 'Future<$symbol>' : symbol);
+}
+
 String _escapeForDartSingleQuotedString(String raw) {
   return raw
       .replaceAll(r'\', r'\\')
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index b9aec2b27994..b5d9cb46b816 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -164,9 +164,22 @@ class Indent {
   }
 }
 
-/// Create the generated channel name for a [func] on a [api].
-String makeChannelName(Api api, Method func, String dartPackageName) {
-  return 'dev.flutter.pigeon.$dartPackageName.${api.name}.${func.name}';
+/// Create the generated channel name for a [method] on an [api].
+String makeChannelName(Api api, Method method, String dartPackageName) {
+  return makeChannelNameWithStrings(
+    apiName: api.name,
+    methodName: method.name,
+    dartPackageName: dartPackageName,
+  );
+}
+
+/// Create the generated channel name for a method on an api.
+String makeChannelNameWithStrings({
+  required String apiName,
+  required String methodName,
+  required String dartPackageName,
+}) {
+  return 'dev.flutter.pigeon.$dartPackageName.$apiName.$methodName';
 }
 
 // TODO(tarrinneal): Determine whether HostDataType is needed.
@@ -541,6 +554,23 @@ void addDocumentationComments(
   DocumentCommentSpecification commentSpec, {
   List<String> generatorComments = const <String>[],
 }) {
+  asDocumentationComments(
+    comments,
+    commentSpec,
+    generatorComments: generatorComments,
+  ).forEach(indent.writeln);
+}
+
+/// Formats documentation comments and adds them to current Indent.
+///
+/// The [comments] list is meant for comments written in the input dart file.
+/// The [generatorComments] list is meant for comments added by the generators.
+/// Include white space for all tokens when called, no assumptions are made.
+Iterable<String> asDocumentationComments(
+  Iterable<String> comments,
+  DocumentCommentSpecification commentSpec, {
+  List<String> generatorComments = const <String>[],
+}) sync* {
   final List<String> allComments = <String>[
     ...comments,
     if (comments.isNotEmpty && generatorComments.isNotEmpty) '',
@@ -549,24 +579,20 @@ void addDocumentationComments(
   String currentLineOpenToken = commentSpec.openCommentToken;
   if (allComments.length > 1) {
     if (commentSpec.closeCommentToken != '') {
-      indent.writeln(commentSpec.openCommentToken);
+      yield commentSpec.openCommentToken;
       currentLineOpenToken = commentSpec.blockContinuationToken;
     }
     for (String line in allComments) {
       if (line.isNotEmpty && line[0] != ' ') {
         line = ' $line';
       }
-      indent.writeln(
-        '$currentLineOpenToken$line',
-      );
+      yield '$currentLineOpenToken$line';
     }
     if (commentSpec.closeCommentToken != '') {
-      indent.writeln(commentSpec.closeCommentToken);
+      yield commentSpec.closeCommentToken;
     }
   } else if (allComments.length == 1) {
-    indent.writeln(
-      '$currentLineOpenToken${allComments.first}${commentSpec.closeCommentToken}',
-    );
+    yield '$currentLineOpenToken${allComments.first}${commentSpec.closeCommentToken}';
   }
 }
 

From 8015a9a97148df0966edaca888c637e95aa84ae9 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 31 Jan 2024 15:19:05 -0500
Subject: [PATCH 18/32] implementation of proxyapis stuff for dart

---
 packages/pigeon/lib/dart/templates.dart |    6 +-
 packages/pigeon/lib/dart_generator.dart | 1589 +++++++++++++----------
 2 files changed, 914 insertions(+), 681 deletions(-)

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index bcc152f13fa4..fe56d16f4fbe 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -3,10 +3,8 @@ import '../generator_tools.dart';
 /// Creates the `InstanceManager` with the passed string values.
 String instanceManagerTemplate({
   required String proxyApiBaseClassName,
-  required List<String> allProxyApiNames,
+  required Iterable<String> allProxyApiNames,
 }) {
-  //const String proxyApiBaseClassName = '${classNamePrefix}ProxyApiBaseClass';
-
   final Iterable<String> apiHandlerSetUps = allProxyApiNames.map(
     (String name) {
       return '$name.${classMemberNamePrefix}setUpMessageHandlers(${classMemberNamePrefix}instanceManager: instanceManager);';
@@ -357,7 +355,7 @@ abstract class $_proxyApiBaseClassName {
 }
 ''';
 
-const String proxyApiCodec = '''
+const String proxyApiBaseCodec = '''
 class $_proxyApiCodecName extends StandardMessageCodec {
  const $_proxyApiCodecName(this.instanceManager);
  final $instanceManagerClassName instanceManager;
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index c3dce2ce2ca2..1dc1b54f2d45 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -4,9 +4,11 @@
 
 import 'package:code_builder/code_builder.dart' as cb;
 import 'package:collection/collection.dart' as collection;
+import 'package:dart_style/dart_style.dart';
 import 'package:path/path.dart' as path;
 
 import 'ast.dart';
+import 'dart/templates.dart';
 import 'functional.dart';
 import 'generator.dart';
 import 'generator_tools.dart';
@@ -450,696 +452,202 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     });
   }
 
-  Iterable<cb.Constructor> _proxyApiConstructors(
-    Iterable<Constructor> constructors, {
-    required String apiName,
+  @override
+  void writeInstanceManager(
+    DartOptions generatorOptions,
+    Root root,
+    Indent indent, {
     required String dartPackageName,
-    required String codecName,
-    required String codecInstanceName,
-    required AstProxyApi? superClassApi,
-    required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> superClassFlutterMethods,
-    required Iterable<Method> interfacesMethods,
-    required Iterable<Method> flutterMethods,
   }) {
-    final cb.Parameter binaryMessengerParameter = cb.Parameter(
-      (cb.ParameterBuilder builder) => builder
-        ..name = '${classMemberNamePrefix}binaryMessenger'
-        ..named = true
-        ..toSuper = true,
-    );
-    final cb.Parameter instanceManagerParameter = cb.Parameter(
-      (cb.ParameterBuilder builder) => builder
-        ..name = _instanceManagerVarName
-        ..named = true
-        ..toSuper = true,
-    );
-    return <cb.Constructor>[
-      // All constructors for this api defined in the pigeon file.
-      ...constructors.map(
-        (Constructor constructor) => cb.Constructor(
-          (cb.ConstructorBuilder builder) {
-            final String channelName = makeChannelNameWithStrings(
-              apiName: apiName,
-              methodName: constructor.name.isNotEmpty
-                  ? constructor.name
-                  : '${classMemberNamePrefix}defaultConstructor',
-              dartPackageName: dartPackageName,
-            );
-            builder
-              ..name = constructor.name.isNotEmpty ? constructor.name : null
-              ..docs.addAll(asDocumentationComments(
-                constructor.documentationComments,
-                _docCommentSpec,
-              ))
-              ..optionalParameters.addAll(
-                <cb.Parameter>[
-                  binaryMessengerParameter,
-                  instanceManagerParameter,
-                  for (final ApiField field in unattachedFields)
-                    cb.Parameter(
-                      (cb.ParameterBuilder builder) => builder
-                        ..name = field.name
-                        ..named = true
-                        ..toThis = true
-                        ..required = !field.type.isNullable,
-                    ),
-                  for (final Method method in superClassFlutterMethods
-                      .followedBy(interfacesMethods)
-                      .followedBy(flutterMethods))
-                    cb.Parameter(
-                      (cb.ParameterBuilder builder) => builder
-                        ..name = method.name
-                        ..named = true
-                        ..toSuper = true
-                        ..required = method.isRequired,
-                    ),
-                  ...constructor.parameters.mapIndexed(
-                    (int index, NamedType parameter) => cb.Parameter(
-                      (cb.ParameterBuilder builder) => builder
-                        ..name = _getParameterName(index, parameter)
-                        ..type = _refer(parameter.type)
-                        ..named = true
-                        ..required = !parameter.type.isNullable,
-                    ),
-                  )
-                ],
-              )
-              ..initializers.addAll(
-                <cb.Code>[
-                  if (superClassApi != null)
-                    const cb.Code('super.${classMemberNamePrefix}detached()')
-                ],
-              )
-              ..body = cb.Block(
-                (cb.BlockBuilder builder) {
-                  final StringBuffer messageCallSink = StringBuffer();
-                  _writeHostMethodMessageCall(
-                    Indent(messageCallSink),
-                    channelName: channelName,
-                    parameters: <Parameter>[
-                      Parameter(
-                        name: '${_varNamePrefix}instanceIdentifier',
-                        type: const TypeDeclaration(
-                          baseName: 'int',
-                          isNullable: false,
-                        ),
-                      ),
-                      ...unattachedFields.map(
-                        (ApiField field) => Parameter(
-                          name: field.name,
-                          type: field.type,
-                        ),
-                      ),
-                      ...constructor.parameters,
-                    ],
-                    returnType: const TypeDeclaration.voidDeclaration(),
-                  );
-                  builder.statements.addAll(<cb.Code>[
-                    const cb.Code(
-                      'final int ${_varNamePrefix}instanceIdentifier = $_instanceManagerVarName.addDartCreatedInstance(this);',
-                    ),
-                    cb.Code('final $codecName $_pigeonChannelCodec =\n'
-                        '    $codecInstanceName;'),
-                    cb.Code(
-                      'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${binaryMessengerParameter.name};',
-                    ),
-                    const cb.Code('() async {'),
-                    cb.Code(messageCallSink.toString()),
-                    const cb.Code('}();'),
-                  ]);
-                },
-              );
-          },
-        ),
+    indent.writeln(
+      instanceManagerTemplate(
+        proxyApiBaseClassName: '${classMemberNamePrefix}ProxyApiBaseClass',
+        allProxyApiNames: root.apis
+            .whereType<AstProxyApi>()
+            .map((AstProxyApi api) => api.name),
       ),
-      // The detached constructor present for every ProxyApi. This constructor
-      // doesn't include a host method call to create a new native class
-      // instance. It is mainly used when the native side once to create a Dart
-      // instance and when the `InstanceManager` wants to create a copy for
-      // garbage collection.
-      cb.Constructor(
-        (cb.ConstructorBuilder builder) => builder
-          ..name = '${classMemberNamePrefix}detached'
-          ..docs.addAll(<String>[
-            '/// Constructs $apiName without creating the associated native object.',
-            '///',
-            '/// This should only be used by subclasses created by this library or to',
-            '/// create copies for an [$instanceManagerClassName].',
-          ])
-          ..optionalParameters.addAll(<cb.Parameter>[
-            binaryMessengerParameter,
-            instanceManagerParameter,
-            for (final ApiField field in unattachedFields)
-              cb.Parameter(
-                (cb.ParameterBuilder builder) => builder
-                  ..name = field.name
-                  ..named = true
-                  ..toThis = true
-                  ..required = !field.type.isNullable,
-              ),
-            for (final Method method in superClassFlutterMethods
-                .followedBy(interfacesMethods)
-                .followedBy(flutterMethods))
-              cb.Parameter(
-                (cb.ParameterBuilder builder) => builder
-                  ..name = method.name
-                  ..named = true
-                  ..toSuper = true
-                  ..required = method.isRequired,
-              ),
-          ])
-          ..initializers.addAll(<cb.Code>[
-            if (superClassApi != null)
-              const cb.Code('super.${classMemberNamePrefix}detached()'),
-          ]),
+    );
+  }
+
+  @override
+  void writeInstanceManagerApi(
+    DartOptions generatorOptions,
+    Root root,
+    Indent indent, {
+    required String dartPackageName,
+  }) {
+    indent.writeln(
+      instanceManagerApiTemplate(
+        dartPackageName: dartPackageName,
+        pigeonChannelCodecVarName: _pigeonChannelCodec,
       ),
-    ];
+    );
   }
 
-  Iterable<cb.Field> _proxyApiFields({
-    required Iterable<ApiField> unattachedFields,
-    required Iterable<ApiField> attachedFields,
-    required String apiName,
+  @override
+  void writeProxyApiBaseCodec(
+    DartOptions generatorOptions,
+    Root root,
+    Indent indent,
+  ) {
+    indent.writeln(proxyApiBaseCodec);
+  }
+
+  @override
+  void writeProxyApi(
+    DartOptions generatorOptions,
+    Root root,
+    Indent indent,
+    AstProxyApi api, {
     required String dartPackageName,
-    required String codecInstanceName,
-    required String codecName,
-    required Iterable<AstProxyApi> interfacesApis,
-    required Iterable<Method> flutterMethods,
-    required bool referencesCodecInstance,
   }) {
-    return <cb.Field>[
-      if (referencesCodecInstance)
-        cb.Field(
-          (cb.FieldBuilder builder) => builder
-            ..name = codecInstanceName
-            ..type = cb.refer(codecName)
-            ..late = true
-            ..modifier = cb.FieldModifier.final$
-            ..assignment = cb.Code('$codecName($_instanceManagerVarName)'),
-        ),
-      for (final ApiField field in unattachedFields)
-        cb.Field(
-          (cb.FieldBuilder builder) => builder
-            ..name = field.name
-            ..type = cb.refer(_addGenericTypesNullable(field.type))
-            ..modifier = cb.FieldModifier.final$
-            ..docs.addAll(asDocumentationComments(
-              field.documentationComments,
-              _docCommentSpec,
-            )),
-        ),
-      for (final Method method in flutterMethods)
-        cb.Field(
-          (cb.FieldBuilder builder) => builder
-            ..name = method.name
-            ..modifier = cb.FieldModifier.final$
-            ..docs.addAll(asDocumentationComments(
-              <String>[
-                ...method.documentationComments,
-                ...<String>[
-                  if (method.documentationComments.isNotEmpty) '',
-                  'Dart:',
-                  'For the associated Native object to be automatically garbage collected,',
-                  "it is required that the implementation of this `Function` doesn't have a",
-                  'strong reference to the encapsulating class instance. When this `Function`',
-                  'references a non-local variable, it is strongly recommended to access it',
-                  'from a `WeakReference`:',
-                  '',
-                  '```dart',
-                  'final WeakReference weakMyVariable = WeakReference(myVariable);',
-                  'final $apiName instance = $apiName(',
-                  '  ${method.name}: ($apiName ${classMemberNamePrefix}instance, ...) {',
-                  '    print(weakMyVariable?.target);',
-                  '  },',
-                  ');',
-                  '```',
-                  '',
-                  'Alternatively, `$instanceManagerClassName.removeWeakReference` can be used to',
-                  'release the associated Native object manually.',
-                ],
-              ],
-              _docCommentSpec,
-            ))
-            ..type = cb.FunctionType(
-              (cb.FunctionTypeBuilder builder) => builder
-                ..returnType = _refer(
-                  method.returnType,
-                  asFuture: method.isAsynchronous,
-                )
-                ..isNullable = !method.isRequired
-                ..requiredParameters.addAll(<cb.Reference>[
-                  cb.refer('$apiName ${classMemberNamePrefix}instance'),
-                  ...method.parameters.mapIndexed(
-                    (int index, NamedType parameter) {
-                      return cb.refer(
-                        '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
-                      );
-                    },
-                  ),
-                ]),
+    const String codecName = '_${classNamePrefix}ProxyApiBaseCodec';
+
+    // Each api has a private codec instance used by every host method,
+    // constructor, or non-static field.
+    final String codecInstanceName = '${_varNamePrefix}codec${api.name}';
+
+    // A list of ProxyApis where each `extends` the API that follows it.
+    final List<AstProxyApi> superClassApisChain =
+        recursiveGetSuperClassApisChain(
+      api,
+    );
+
+    // All ProxyApis this API `implements` and all the interfaces those APIs
+    // `implements`.
+    final Set<AstProxyApi> interfacesApis = recursiveFindAllInterfaceApis(api);
+
+    // All methods inherited from interfaces and the interfaces of interfaces.
+    final List<Method> interfacesMethods = <Method>[];
+    for (final AstProxyApi proxyApi in interfacesApis) {
+      interfacesMethods.addAll(proxyApi.methods);
+    }
+
+    // A list of Flutter methods inherited from the ProxyApi that this ProxyApi
+    // `extends`. This also recursively checks the ProxyApi that the super class
+    // `extends` and so on.
+    //
+    // This also includes methods that super classes inherited from interfaces
+    // with `implements`.
+    final List<Method> superClassFlutterMethods = <Method>[];
+    for (final AstProxyApi proxyApi in superClassApisChain.reversed) {
+      superClassFlutterMethods.addAll(proxyApi.flutterMethods);
+    }
+    if (api.superClass != null) {
+      final Set<AstProxyApi> superClassInterfacesApis =
+          recursiveFindAllInterfaceApis(
+        api.superClass!.associatedProxyApi!,
+      );
+      for (final AstProxyApi proxyApi in superClassInterfacesApis) {
+        superClassFlutterMethods.addAll(proxyApi.methods);
+      }
+    }
+
+    // Ast class used by code_builder to generate the code.
+    final cb.Class proxyApi = cb.Class(
+      (cb.ClassBuilder builder) => builder
+        ..name = api.name
+        ..extend = api.superClass != null
+            ? cb.refer(api.superClass!.baseName)
+            : cb.refer('${classNamePrefix}ProxyApiBaseClass')
+        ..implements.addAll(
+          api.interfaces.map(
+            (TypeDeclaration type) => cb.refer(type.baseName),
+          ),
+        )
+        ..docs.addAll(
+          asDocumentationComments(api.documentationComments, _docCommentSpec),
+        )
+        ..constructors.addAll(_proxyApiConstructors(
+          api.constructors,
+          apiName: api.name,
+          dartPackageName: dartPackageName,
+          codecName: codecName,
+          codecInstanceName: codecInstanceName,
+          superClassApi: api.superClass?.associatedProxyApi,
+          unattachedFields: api.unattachedFields,
+          declaredAndInheritedFlutterMethods: superClassFlutterMethods
+              .followedBy(interfacesMethods)
+              .followedBy(api.flutterMethods),
+        ))
+        ..constructors.add(
+          _proxyApiDetachedConstructor(
+            apiName: api.name,
+            superClassApi: api.superClass?.associatedProxyApi,
+            unattachedFields: api.unattachedFields,
+            declaredAndInheritedFlutterMethods: superClassFlutterMethods
+                .followedBy(interfacesMethods)
+                .followedBy(api.flutterMethods),
+          ),
+        )
+        ..fields.addAll(<cb.Field>[
+          if (api.methods.isNotEmpty ||
+              api.constructors.isNotEmpty ||
+              api.attachedFields.any((ApiField field) => !field.isStatic))
+            _proxyApiCodecInstanceField(
+              codecInstanceName: codecInstanceName,
+              codecName: codecName,
             ),
-        ),
-      for (final AstProxyApi proxyApi in interfacesApis)
-        for (final Method method in proxyApi.methods)
-          cb.Field(
-            (cb.FieldBuilder builder) => builder
-              ..name = method.name
-              ..modifier = cb.FieldModifier.final$
-              ..annotations.add(cb.refer('override'))
-              ..docs.addAll(asDocumentationComments(
-                method.documentationComments,
-                _docCommentSpec,
-              ))
-              ..type = cb.FunctionType(
-                (cb.FunctionTypeBuilder builder) => builder
-                  ..returnType = _refer(
-                    method.returnType,
-                    asFuture: method.isAsynchronous,
-                  )
-                  ..isNullable = !method.isRequired
-                  ..requiredParameters.addAll(<cb.Reference>[
-                    cb.refer(
-                      '${proxyApi.name} ${classMemberNamePrefix}instance',
-                    ),
-                    ...method.parameters.mapIndexed(
-                      (int index, NamedType parameter) {
-                        return cb.refer(
-                          '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
-                        );
-                      },
-                    ),
-                  ]),
-              ),
+        ])
+        ..fields.addAll(_proxyApiUnattachedFields(api.unattachedFields))
+        ..fields.addAll(_proxyApiFlutterMethodFields(
+          api.flutterMethods,
+          apiName: api.name,
+        ))
+        ..fields.addAll(_proxyApiInterfaceApiFields(interfacesApis))
+        ..fields.addAll(_proxyApiattachedFields(api.attachedFields))
+        ..methods.add(
+          _proxyApiSetUpMessageHandlerMethod(
+            flutterMethods: api.flutterMethods,
+            apiName: api.name,
+            dartPackageName: dartPackageName,
+            codecName: codecName,
+            unattachedFields: api.unattachedFields,
+            hasCallbackConstructor: api.methods
+                .followedBy(superClassFlutterMethods)
+                .followedBy(interfacesMethods)
+                .every((Method method) => !method.isRequired),
           ),
-      for (final ApiField field in attachedFields)
-        cb.Field(
-          (cb.FieldBuilder builder) => builder
-            ..name = field.name
-            ..type = cb.refer(_addGenericTypesNullable(field.type))
-            ..modifier = cb.FieldModifier.final$
-            ..static = field.isStatic
-            ..late = !field.isStatic
-            ..docs.addAll(asDocumentationComments(
-              field.documentationComments,
-              _docCommentSpec,
-            ))
-            ..assignment = cb.Code('$_varNamePrefix${field.name}()'),
-        ),
-    ];
+        )
+        ..methods.addAll(
+          _proxyApiAttachedFieldMethods(
+            api.attachedFields,
+            apiName: api.name,
+            dartPackageName: dartPackageName,
+            codecInstanceName: codecInstanceName,
+            codecName: codecName,
+          ),
+        )
+        ..methods.addAll(_proxyApiHostMethods(
+          api.hostMethods,
+          apiName: api.name,
+          dartPackageName: dartPackageName,
+          codecInstanceName: codecInstanceName,
+          codecName: codecName,
+        ))
+        ..methods.add(_proxyApiCopyMethod(
+          flutterMethods: api.flutterMethods,
+          superClassFlutterMethods: superClassFlutterMethods,
+          apiName: api.name,
+          unattachedFields: api.unattachedFields,
+          interfacesApis: interfacesApis,
+        )),
+    );
+
+    final cb.DartEmitter emitter = cb.DartEmitter(useNullSafetySyntax: true);
+    indent.write(DartFormatter().format('${proxyApi.accept(emitter)}'));
   }
 
-  Iterable<cb.Method> _proxyApiMethods({
-    required Iterable<Method> hostMethods,
-    required Iterable<Method> flutterMethods,
-    required Iterable<Method> superClassFlutterMethods,
-    required String apiName,
+  /// Generates Dart source code for test support libraries based on the given AST
+  /// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
+  /// path of the generated dart code to be tested. [testOutPath] is where the
+  /// test code will be generated.
+  void generateTest(
+    DartOptions generatorOptions,
+    Root root,
+    StringSink sink, {
     required String dartPackageName,
-    required String codecInstanceName,
-    required String codecName,
-    required Iterable<ApiField> unattachedFields,
-    required Iterable<ApiField> attachedFields,
-    required Iterable<AstProxyApi> interfacesApis,
-    required bool hasCallbackConstructor,
-  }) {
-    return <cb.Method>[
-      // Flutter methods message handler `*setUpMessageHandlers()`
-      cb.Method.returnsVoid(
-        (cb.MethodBuilder builder) => builder
-          ..name = '${classMemberNamePrefix}setUpMessageHandlers'
-          ..returns = cb.refer('void')
-          ..static = true
-          ..optionalParameters.addAll(<cb.Parameter>[
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = '${classMemberNamePrefix}clearHandlers'
-                ..type = cb.refer('bool')
-                ..named = true
-                ..defaultTo = const cb.Code('false'),
-            ),
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = '${classMemberNamePrefix}binaryMessenger'
-                ..named = true
-                ..type = cb.refer('BinaryMessenger?'),
-            ),
-            cb.Parameter(
-              (cb.ParameterBuilder builder) => builder
-                ..name = _instanceManagerVarName
-                ..named = true
-                ..type = cb.refer('$instanceManagerClassName?'),
-            ),
-            if (hasCallbackConstructor)
-              cb.Parameter(
-                (cb.ParameterBuilder builder) => builder
-                  ..name = '${classMemberNamePrefix}newInstance'
-                  ..named = true
-                  ..type = cb.FunctionType(
-                    (cb.FunctionTypeBuilder builder) => builder
-                      ..returnType = cb.refer(apiName)
-                      ..isNullable = true
-                      ..requiredParameters.addAll(
-                        unattachedFields.mapIndexed(
-                          (int index, ApiField field) {
-                            return cb.refer(
-                              '${_addGenericTypesNullable(field.type)} ${_getParameterName(index, field)}',
-                            );
-                          },
-                        ),
-                      ),
-                  ),
-              ),
-            for (final Method method in flutterMethods)
-              cb.Parameter(
-                (cb.ParameterBuilder builder) => builder
-                  ..name = method.name
-                  ..type = cb.FunctionType(
-                    (cb.FunctionTypeBuilder builder) => builder
-                      ..returnType = _refer(
-                        method.returnType,
-                        asFuture: method.isAsynchronous,
-                      )
-                      ..isNullable = true
-                      ..requiredParameters.addAll(<cb.Reference>[
-                        cb.refer('$apiName ${classMemberNamePrefix}instance'),
-                        ...method.parameters.mapIndexed(
-                          (int index, NamedType parameter) {
-                            return cb.refer(
-                              '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
-                            );
-                          },
-                        ),
-                      ]),
-                  ),
-              ),
-          ])
-          ..body = cb.Block.of(<cb.Code>[
-            cb.Code(
-              'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
-            ),
-            const cb.Code(
-              'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
-            ),
-            if (hasCallbackConstructor)
-              ...cb.Block((cb.BlockBuilder builder) {
-                final StringBuffer messageHandlerSink = StringBuffer();
-                const String methodName = '${classMemberNamePrefix}newInstance';
-                _writeFlutterMethodMessageHandler(
-                  Indent(messageHandlerSink),
-                  name: methodName,
-                  parameters: <Parameter>[
-                    Parameter(
-                      name: '${classMemberNamePrefix}instanceIdentifier',
-                      type: const TypeDeclaration(
-                        baseName: 'int',
-                        isNullable: false,
-                      ),
-                    ),
-                    ...unattachedFields.map(
-                      (ApiField field) =>
-                          Parameter(name: field.name, type: field.type),
-                    ),
-                  ],
-                  returnType: const TypeDeclaration.voidDeclaration(),
-                  channelName: makeChannelNameWithStrings(
-                    apiName: apiName,
-                    methodName: methodName,
-                    dartPackageName: dartPackageName,
-                  ),
-                  isMockHandler: false,
-                  isAsynchronous: false,
-                  nullHandlerExpression:
-                      '${classMemberNamePrefix}clearHandlers',
-                  onCreateApiCall: (
-                    String methodName,
-                    Iterable<Parameter> parameters,
-                    Iterable<String> safeArgumentNames,
-                  ) {
-                    final String argsAsNamedParams = map2(
-                      parameters,
-                      safeArgumentNames,
-                      (Parameter parameter, String safeArgName) {
-                        return '${parameter.name}: $safeArgName,\n';
-                      },
-                    ).skip(1).join();
-                    return '($_instanceManagerVarName ?? $instanceManagerClassName.instance)\n'
-                        '    .addHostCreatedInstance(\n'
-                        '  $methodName?.call(${safeArgumentNames.skip(1).join(',')}) ??\n'
-                        '      $apiName.${classMemberNamePrefix}detached('
-                        '        ${classMemberNamePrefix}binaryMessenger: ${classMemberNamePrefix}binaryMessenger,\n'
-                        '        $_instanceManagerVarName: $_instanceManagerVarName,\n'
-                        '        $argsAsNamedParams\n'
-                        '      ),\n'
-                        '  ${safeArgumentNames.first},\n'
-                        ')';
-                  },
-                );
-                builder.statements.add(cb.Code(messageHandlerSink.toString()));
-              }).statements,
-            for (final Method method in flutterMethods)
-              ...cb.Block((cb.BlockBuilder builder) {
-                final StringBuffer messageHandlerSink = StringBuffer();
-                _writeFlutterMethodMessageHandler(
-                  Indent(messageHandlerSink),
-                  name: method.name,
-                  parameters: <Parameter>[
-                    Parameter(
-                      name: '${classMemberNamePrefix}instance',
-                      type: TypeDeclaration(
-                        baseName: apiName,
-                        isNullable: false,
-                      ),
-                    ),
-                    ...method.parameters,
-                  ],
-                  returnType: TypeDeclaration(
-                    baseName: method.returnType.baseName,
-                    isNullable:
-                        !method.isRequired || method.returnType.isNullable,
-                    typeArguments: method.returnType.typeArguments,
-                    associatedEnum: method.returnType.associatedEnum,
-                    associatedClass: method.returnType.associatedClass,
-                    associatedProxyApi: method.returnType.associatedProxyApi,
-                  ),
-                  channelName: makeChannelNameWithStrings(
-                    apiName: apiName,
-                    methodName: method.name,
-                    dartPackageName: dartPackageName,
-                  ),
-                  isMockHandler: false,
-                  isAsynchronous: method.isAsynchronous,
-                  nullHandlerExpression:
-                      '${classMemberNamePrefix}clearHandlers',
-                  onCreateApiCall: (
-                    String methodName,
-                    Iterable<Parameter> parameters,
-                    Iterable<String> safeArgumentNames,
-                  ) {
-                    final String nullability = method.isRequired ? '' : '?';
-                    return '($methodName ?? ${safeArgumentNames.first}.$methodName)$nullability.call(${safeArgumentNames.join(',')})';
-                  },
-                );
-                builder.statements.add(cb.Code(messageHandlerSink.toString()));
-              }).statements,
-          ]),
-      ),
-      for (final ApiField field in attachedFields)
-        cb.Method(
-          (cb.MethodBuilder builder) {
-            final String type = _addGenericTypesNullable(field.type);
-            const String instanceName = '${_varNamePrefix}instance';
-            const String identifierInstanceName =
-                '${_varNamePrefix}instanceIdentifier';
-            builder
-              ..name = '$_varNamePrefix${field.name}'
-              ..static = field.isStatic
-              ..returns = cb.refer(type)
-              ..body = cb.Block(
-                (cb.BlockBuilder builder) {
-                  final StringBuffer messageCallSink = StringBuffer();
-                  _writeHostMethodMessageCall(
-                    Indent(messageCallSink),
-                    channelName: makeChannelNameWithStrings(
-                      apiName: apiName,
-                      methodName: field.name,
-                      dartPackageName: dartPackageName,
-                    ),
-                    parameters: <Parameter>[
-                      if (!field.isStatic)
-                        Parameter(
-                          name: 'this',
-                          type: TypeDeclaration(
-                            baseName: apiName,
-                            isNullable: false,
-                          ),
-                        ),
-                      Parameter(
-                        name: identifierInstanceName,
-                        type: const TypeDeclaration(
-                          baseName: 'int',
-                          isNullable: false,
-                        ),
-                      ),
-                    ],
-                    returnType: const TypeDeclaration.voidDeclaration(),
-                  );
-                  builder.statements.addAll(<cb.Code>[
-                    if (!field.isStatic) ...<cb.Code>[
-                      cb.Code(
-                        'final $type $instanceName = $type.${classMemberNamePrefix}detached(\n'
-                        '  pigeon_binaryMessenger: pigeon_binaryMessenger,\n'
-                        '  pigeon_instanceManager: pigeon_instanceManager,\n'
-                        ');',
-                      ),
-                      cb.Code('final $codecName $_pigeonChannelCodec =\n'
-                          '    $codecInstanceName;'),
-                      const cb.Code(
-                        'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
-                      ),
-                      const cb.Code(
-                        'final int $identifierInstanceName = $_instanceManagerVarName.addDartCreatedInstance($instanceName);',
-                      ),
-                    ] else ...<cb.Code>[
-                      cb.Code(
-                        'final $type $instanceName = $type.${classMemberNamePrefix}detached();',
-                      ),
-                      cb.Code(
-                        'final $codecName $_pigeonChannelCodec = $codecName($instanceManagerClassName.instance);',
-                      ),
-                      const cb.Code(
-                        'final BinaryMessenger ${_varNamePrefix}binaryMessenger = ServicesBinding.instance.defaultBinaryMessenger;',
-                      ),
-                      const cb.Code(
-                        'final int $identifierInstanceName = $instanceManagerClassName.instance.addDartCreatedInstance($instanceName);',
-                      ),
-                    ],
-                    const cb.Code('() async {'),
-                    cb.Code(messageCallSink.toString()),
-                    const cb.Code('}();'),
-                    const cb.Code('return $instanceName;'),
-                  ]);
-                },
-              );
-          },
-        ),
-      for (final Method method in hostMethods)
-        cb.Method(
-          (cb.MethodBuilder builder) => builder
-            ..name = method.name
-            ..static = method.isStatic
-            ..modifier = cb.MethodModifier.async
-            ..docs.addAll(asDocumentationComments(
-              method.documentationComments,
-              _docCommentSpec,
-            ))
-            ..returns = _refer(method.returnType, asFuture: true)
-            ..requiredParameters.addAll(
-              method.parameters.mapIndexed(
-                (int index, NamedType parameter) => cb.Parameter(
-                  (cb.ParameterBuilder builder) => builder
-                    ..name = _getParameterName(index, parameter)
-                    ..type = cb.refer(
-                      _addGenericTypesNullable(parameter.type),
-                    ),
-                ),
-              ),
-            )
-            ..optionalParameters.addAll(<cb.Parameter>[
-              if (method.isStatic) ...<cb.Parameter>[
-                cb.Parameter(
-                  (cb.ParameterBuilder builder) => builder
-                    ..name = '${classMemberNamePrefix}binaryMessenger'
-                    ..type = cb.refer('BinaryMessenger?')
-                    ..named = true,
-                ),
-                cb.Parameter(
-                  (cb.ParameterBuilder builder) => builder
-                    ..name = _instanceManagerVarName
-                    ..type = cb.refer('$instanceManagerClassName?'),
-                ),
-              ],
-            ])
-            ..body = cb.Block(
-              (cb.BlockBuilder builder) {
-                final StringBuffer messageCallSink = StringBuffer();
-                _writeHostMethodMessageCall(
-                  Indent(messageCallSink),
-                  channelName: makeChannelNameWithStrings(
-                    apiName: apiName,
-                    methodName: method.name,
-                    dartPackageName: dartPackageName,
-                  ),
-                  parameters: <Parameter>[
-                    if (!method.isStatic)
-                      Parameter(
-                        name: 'this',
-                        type: TypeDeclaration(
-                          baseName: apiName,
-                          isNullable: false,
-                        ),
-                      ),
-                    ...method.parameters,
-                  ],
-                  returnType: method.returnType,
-                );
-                builder.statements.addAll(<cb.Code>[
-                  if (!method.isStatic)
-                    cb.Code('final $codecName $_pigeonChannelCodec =\n'
-                        '    $codecInstanceName;')
-                  else
-                    cb.Code(
-                      'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
-                    ),
-                  const cb.Code(
-                    'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
-                  ),
-                  cb.Code(messageCallSink.toString()),
-                ]);
-              },
-            ),
-        ),
-      cb.Method(
-        (cb.MethodBuilder builder) => builder
-          ..name = '${classMemberNamePrefix}copy'
-          ..returns = cb.refer(apiName)
-          ..annotations.add(cb.refer('override'))
-          ..body = cb.Block.of(<cb.Code>[
-            cb
-                .refer('$apiName.${classMemberNamePrefix}detached')
-                .call(
-                  <cb.Expression>[],
-                  <String, cb.Expression>{
-                    '${classMemberNamePrefix}binaryMessenger':
-                        cb.refer('${classMemberNamePrefix}binaryMessenger'),
-                    _instanceManagerVarName: cb.refer(_instanceManagerVarName),
-                    for (final ApiField field in unattachedFields)
-                      field.name: cb.refer(field.name),
-                    for (final Method method in superClassFlutterMethods)
-                      method.name: cb.refer(method.name),
-                    for (final AstProxyApi proxyApi in interfacesApis)
-                      for (final Method method in proxyApi.methods)
-                        method.name: cb.refer(method.name),
-                    for (final Method method in flutterMethods)
-                      method.name: cb.refer(method.name),
-                  },
-                )
-                .returned
-                .statement,
-          ]),
-      ),
-    ];
-  }
-
-  /// Generates Dart source code for test support libraries based on the given AST
-  /// represented by [root], outputting the code to [sink]. [sourceOutPath] is the
-  /// path of the generated dart code to be tested. [testOutPath] is where the
-  /// test code will be generated.
-  void generateTest(
-    DartOptions generatorOptions,
-    Root root,
-    StringSink sink, {
-    required String dartPackageName,
-    required String dartOutputPackageName,
+    required String dartOutputPackageName,
   }) {
     final Indent indent = Indent(sink);
     final String sourceOutPath = generatorOptions.sourceOutPath ?? '';
@@ -1489,6 +997,733 @@ if (${_varNamePrefix}replyList == null) {
   ) {
     return 'api.$methodName(${safeArgumentNames.join(', ')})';
   }
+
+  Iterable<cb.Constructor> _proxyApiConstructors(
+    Iterable<Constructor> constructors, {
+    required String apiName,
+    required String dartPackageName,
+    required String codecName,
+    required String codecInstanceName,
+    required AstProxyApi? superClassApi,
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<Method> declaredAndInheritedFlutterMethods,
+  }) sync* {
+    final cb.Parameter binaryMessengerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}binaryMessenger'
+        ..named = true
+        ..toSuper = true,
+    );
+    final cb.Parameter instanceManagerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = _instanceManagerVarName
+        ..named = true
+        ..toSuper = true,
+    );
+    for (final Constructor constructor in constructors) {
+      yield cb.Constructor(
+        (cb.ConstructorBuilder builder) {
+          final String channelName = makeChannelNameWithStrings(
+            apiName: apiName,
+            methodName: constructor.name.isNotEmpty
+                ? constructor.name
+                : '${classMemberNamePrefix}defaultConstructor',
+            dartPackageName: dartPackageName,
+          );
+          builder
+            ..name = constructor.name.isNotEmpty ? constructor.name : null
+            ..docs.addAll(asDocumentationComments(
+              constructor.documentationComments,
+              _docCommentSpec,
+            ))
+            ..optionalParameters.addAll(
+              <cb.Parameter>[
+                binaryMessengerParameter,
+                instanceManagerParameter,
+                for (final ApiField field in unattachedFields)
+                  cb.Parameter(
+                    (cb.ParameterBuilder builder) => builder
+                      ..name = field.name
+                      ..named = true
+                      ..toThis = true
+                      ..required = !field.type.isNullable,
+                  ),
+                for (final Method method in declaredAndInheritedFlutterMethods)
+                  cb.Parameter(
+                    (cb.ParameterBuilder builder) => builder
+                      ..name = method.name
+                      ..named = true
+                      ..toSuper = true
+                      ..required = method.isRequired,
+                  ),
+                ...constructor.parameters.mapIndexed(
+                  (int index, NamedType parameter) => cb.Parameter(
+                    (cb.ParameterBuilder builder) => builder
+                      ..name = _getParameterName(index, parameter)
+                      ..type = _refer(parameter.type)
+                      ..named = true
+                      ..required = !parameter.type.isNullable,
+                  ),
+                )
+              ],
+            )
+            ..initializers.addAll(
+              <cb.Code>[
+                if (superClassApi != null)
+                  const cb.Code('super.${classMemberNamePrefix}detached()')
+              ],
+            )
+            ..body = cb.Block(
+              (cb.BlockBuilder builder) {
+                final StringBuffer messageCallSink = StringBuffer();
+                _writeHostMethodMessageCall(
+                  Indent(messageCallSink),
+                  channelName: channelName,
+                  parameters: <Parameter>[
+                    Parameter(
+                      name: '${_varNamePrefix}instanceIdentifier',
+                      type: const TypeDeclaration(
+                        baseName: 'int',
+                        isNullable: false,
+                      ),
+                    ),
+                    ...unattachedFields.map(
+                      (ApiField field) => Parameter(
+                        name: field.name,
+                        type: field.type,
+                      ),
+                    ),
+                    ...constructor.parameters,
+                  ],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                );
+
+                builder.statements.addAll(<cb.Code>[
+                  const cb.Code(
+                    'final int ${_varNamePrefix}instanceIdentifier = $_instanceManagerVarName.addDartCreatedInstance(this);',
+                  ),
+                  cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                      '    $codecInstanceName;'),
+                  cb.Code(
+                    'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${binaryMessengerParameter.name};',
+                  ),
+                  const cb.Code('() async {'),
+                  cb.Code(messageCallSink.toString()),
+                  const cb.Code('}();'),
+                ]);
+              },
+            );
+        },
+      );
+    }
+  }
+
+  /// The detached constructor present for every ProxyApi.
+  ///
+  /// This constructor doesn't include a host method call to create a new native
+  /// class instance. It is mainly used when the native side once to create a
+  /// Dart instance and when the `InstanceManager` wants to create a copy for
+  /// garbage collection.
+  cb.Constructor _proxyApiDetachedConstructor({
+    required String apiName,
+    required AstProxyApi? superClassApi,
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<Method> declaredAndInheritedFlutterMethods,
+  }) {
+    final cb.Parameter binaryMessengerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}binaryMessenger'
+        ..named = true
+        ..toSuper = true,
+    );
+    final cb.Parameter instanceManagerParameter = cb.Parameter(
+      (cb.ParameterBuilder builder) => builder
+        ..name = _instanceManagerVarName
+        ..named = true
+        ..toSuper = true,
+    );
+    return cb.Constructor(
+      (cb.ConstructorBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}detached'
+        ..docs.addAll(<String>[
+          '/// Constructs $apiName without creating the associated native object.',
+          '///',
+          '/// This should only be used by subclasses created by this library or to',
+          '/// create copies for an [$instanceManagerClassName].',
+        ])
+        ..optionalParameters.addAll(<cb.Parameter>[
+          binaryMessengerParameter,
+          instanceManagerParameter,
+          for (final ApiField field in unattachedFields)
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = field.name
+                ..named = true
+                ..toThis = true
+                ..required = !field.type.isNullable,
+            ),
+          for (final Method method in declaredAndInheritedFlutterMethods)
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = method.name
+                ..named = true
+                ..toSuper = true
+                ..required = method.isRequired,
+            ),
+        ])
+        ..initializers.addAll(<cb.Code>[
+          if (superClassApi != null)
+            const cb.Code('super.${classMemberNamePrefix}detached()'),
+        ]),
+    );
+  }
+
+  cb.Field _proxyApiCodecInstanceField({
+    required String codecInstanceName,
+    required String codecName,
+  }) {
+    return cb.Field(
+      (cb.FieldBuilder builder) => builder
+        ..name = codecInstanceName
+        ..type = cb.refer(codecName)
+        ..late = true
+        ..modifier = cb.FieldModifier.final$
+        ..assignment = cb.Code('$codecName($_instanceManagerVarName)'),
+    );
+  }
+
+  Iterable<cb.Field> _proxyApiUnattachedFields(
+      Iterable<ApiField> fields) sync* {
+    for (final ApiField field in fields) {
+      yield cb.Field(
+        (cb.FieldBuilder builder) => builder
+          ..name = field.name
+          ..type = cb.refer(_addGenericTypesNullable(field.type))
+          ..modifier = cb.FieldModifier.final$
+          ..docs.addAll(asDocumentationComments(
+            field.documentationComments,
+            _docCommentSpec,
+          )),
+      );
+    }
+  }
+
+  Iterable<cb.Field> _proxyApiFlutterMethodFields(
+    Iterable<Method> methods, {
+    required String apiName,
+  }) sync* {
+    for (final Method method in methods) {
+      yield cb.Field(
+        (cb.FieldBuilder builder) => builder
+          ..name = method.name
+          ..modifier = cb.FieldModifier.final$
+          ..docs.addAll(asDocumentationComments(
+            <String>[
+              ...method.documentationComments,
+              ...<String>[
+                if (method.documentationComments.isNotEmpty) '',
+                'Dart:',
+                'For the associated Native object to be automatically garbage collected,',
+                "it is required that the implementation of this `Function` doesn't have a",
+                'strong reference to the encapsulating class instance. When this `Function`',
+                'references a non-local variable, it is strongly recommended to access it',
+                'from a `WeakReference`:',
+                '',
+                '```dart',
+                'final WeakReference weakMyVariable = WeakReference(myVariable);',
+                'final $apiName instance = $apiName(',
+                '  ${method.name}: ($apiName ${classMemberNamePrefix}instance, ...) {',
+                '    print(weakMyVariable?.target);',
+                '  },',
+                ');',
+                '```',
+                '',
+                'Alternatively, `$instanceManagerClassName.removeWeakReference` can be used to',
+                'release the associated Native object manually.',
+              ],
+            ],
+            _docCommentSpec,
+          ))
+          ..type = cb.FunctionType(
+            (cb.FunctionTypeBuilder builder) => builder
+              ..returnType = _refer(
+                method.returnType,
+                asFuture: method.isAsynchronous,
+              )
+              ..isNullable = !method.isRequired
+              ..requiredParameters.addAll(<cb.Reference>[
+                cb.refer('$apiName ${classMemberNamePrefix}instance'),
+                ...method.parameters.mapIndexed(
+                  (int index, NamedType parameter) {
+                    return cb.refer(
+                      '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                    );
+                  },
+                ),
+              ]),
+          ),
+      );
+    }
+  }
+
+  Iterable<cb.Field> _proxyApiInterfaceApiFields(
+    Iterable<AstProxyApi> apis,
+  ) sync* {
+    for (final AstProxyApi proxyApi in apis) {
+      for (final Method method in proxyApi.methods) {
+        yield cb.Field(
+          (cb.FieldBuilder builder) => builder
+            ..name = method.name
+            ..modifier = cb.FieldModifier.final$
+            ..annotations.add(cb.refer('override'))
+            ..docs.addAll(asDocumentationComments(
+              method.documentationComments,
+              _docCommentSpec,
+            ))
+            ..type = cb.FunctionType(
+              (cb.FunctionTypeBuilder builder) => builder
+                ..returnType = _refer(
+                  method.returnType,
+                  asFuture: method.isAsynchronous,
+                )
+                ..isNullable = !method.isRequired
+                ..requiredParameters.addAll(<cb.Reference>[
+                  cb.refer(
+                    '${proxyApi.name} ${classMemberNamePrefix}instance',
+                  ),
+                  ...method.parameters.mapIndexed(
+                    (int index, NamedType parameter) {
+                      return cb.refer(
+                        '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                      );
+                    },
+                  ),
+                ]),
+            ),
+        );
+      }
+    }
+  }
+
+  Iterable<cb.Field> _proxyApiattachedFields(Iterable<ApiField> fields) sync* {
+    for (final ApiField field in fields) {
+      yield cb.Field(
+        (cb.FieldBuilder builder) => builder
+          ..name = field.name
+          ..type = cb.refer(_addGenericTypesNullable(field.type))
+          ..modifier = cb.FieldModifier.final$
+          ..static = field.isStatic
+          ..late = !field.isStatic
+          ..docs.addAll(asDocumentationComments(
+            field.documentationComments,
+            _docCommentSpec,
+          ))
+          ..assignment = cb.Code('$_varNamePrefix${field.name}()'),
+      );
+    }
+  }
+
+  cb.Method _proxyApiSetUpMessageHandlerMethod({
+    required Iterable<Method> flutterMethods,
+    required String apiName,
+    required String dartPackageName,
+    required String codecName,
+    required Iterable<ApiField> unattachedFields,
+    required bool hasCallbackConstructor,
+  }) {
+    return cb.Method.returnsVoid(
+      (cb.MethodBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}setUpMessageHandlers'
+        ..returns = cb.refer('void')
+        ..static = true
+        ..optionalParameters.addAll(<cb.Parameter>[
+          cb.Parameter(
+            (cb.ParameterBuilder builder) => builder
+              ..name = '${classMemberNamePrefix}clearHandlers'
+              ..type = cb.refer('bool')
+              ..named = true
+              ..defaultTo = const cb.Code('false'),
+          ),
+          cb.Parameter(
+            (cb.ParameterBuilder builder) => builder
+              ..name = '${classMemberNamePrefix}binaryMessenger'
+              ..named = true
+              ..type = cb.refer('BinaryMessenger?'),
+          ),
+          cb.Parameter(
+            (cb.ParameterBuilder builder) => builder
+              ..name = _instanceManagerVarName
+              ..named = true
+              ..type = cb.refer('$instanceManagerClassName?'),
+          ),
+          if (hasCallbackConstructor)
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = '${classMemberNamePrefix}newInstance'
+                ..named = true
+                ..type = cb.FunctionType(
+                  (cb.FunctionTypeBuilder builder) => builder
+                    ..returnType = cb.refer(apiName)
+                    ..isNullable = true
+                    ..requiredParameters.addAll(
+                      unattachedFields.mapIndexed(
+                        (int index, ApiField field) {
+                          return cb.refer(
+                            '${_addGenericTypesNullable(field.type)} ${_getParameterName(index, field)}',
+                          );
+                        },
+                      ),
+                    ),
+                ),
+            ),
+          for (final Method method in flutterMethods)
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = method.name
+                ..type = cb.FunctionType(
+                  (cb.FunctionTypeBuilder builder) => builder
+                    ..returnType = _refer(
+                      method.returnType,
+                      asFuture: method.isAsynchronous,
+                    )
+                    ..isNullable = true
+                    ..requiredParameters.addAll(<cb.Reference>[
+                      cb.refer('$apiName ${classMemberNamePrefix}instance'),
+                      ...method.parameters.mapIndexed(
+                        (int index, NamedType parameter) {
+                          return cb.refer(
+                            '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
+                          );
+                        },
+                      ),
+                    ]),
+                ),
+            ),
+        ])
+        ..body = cb.Block.of(<cb.Code>[
+          cb.Code(
+            'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
+          ),
+          const cb.Code(
+            'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+          ),
+          if (hasCallbackConstructor)
+            ...cb.Block((cb.BlockBuilder builder) {
+              final StringBuffer messageHandlerSink = StringBuffer();
+              const String methodName = '${classMemberNamePrefix}newInstance';
+              _writeFlutterMethodMessageHandler(
+                Indent(messageHandlerSink),
+                name: methodName,
+                parameters: <Parameter>[
+                  Parameter(
+                    name: '${classMemberNamePrefix}instanceIdentifier',
+                    type: const TypeDeclaration(
+                      baseName: 'int',
+                      isNullable: false,
+                    ),
+                  ),
+                  ...unattachedFields.map(
+                    (ApiField field) {
+                      return Parameter(name: field.name, type: field.type);
+                    },
+                  ),
+                ],
+                returnType: const TypeDeclaration.voidDeclaration(),
+                channelName: makeChannelNameWithStrings(
+                  apiName: apiName,
+                  methodName: methodName,
+                  dartPackageName: dartPackageName,
+                ),
+                isMockHandler: false,
+                isAsynchronous: false,
+                nullHandlerExpression: '${classMemberNamePrefix}clearHandlers',
+                onCreateApiCall: (
+                  String methodName,
+                  Iterable<Parameter> parameters,
+                  Iterable<String> safeArgumentNames,
+                ) {
+                  final String argsAsNamedParams = map2(
+                    parameters,
+                    safeArgumentNames,
+                    (Parameter parameter, String safeArgName) {
+                      return '${parameter.name}: $safeArgName,\n';
+                    },
+                  ).skip(1).join();
+                  return '($_instanceManagerVarName ?? $instanceManagerClassName.instance)\n'
+                      '    .addHostCreatedInstance(\n'
+                      '  $methodName?.call(${safeArgumentNames.skip(1).join(',')}) ??\n'
+                      '      $apiName.${classMemberNamePrefix}detached('
+                      '        ${classMemberNamePrefix}binaryMessenger: ${classMemberNamePrefix}binaryMessenger,\n'
+                      '        $_instanceManagerVarName: $_instanceManagerVarName,\n'
+                      '        $argsAsNamedParams\n'
+                      '      ),\n'
+                      '  ${safeArgumentNames.first},\n'
+                      ')';
+                },
+              );
+              builder.statements.add(cb.Code(messageHandlerSink.toString()));
+            }).statements,
+          for (final Method method in flutterMethods)
+            ...cb.Block((cb.BlockBuilder builder) {
+              final StringBuffer messageHandlerSink = StringBuffer();
+              _writeFlutterMethodMessageHandler(
+                Indent(messageHandlerSink),
+                name: method.name,
+                parameters: <Parameter>[
+                  Parameter(
+                    name: '${classMemberNamePrefix}instance',
+                    type: TypeDeclaration(
+                      baseName: apiName,
+                      isNullable: false,
+                    ),
+                  ),
+                  ...method.parameters,
+                ],
+                returnType: TypeDeclaration(
+                  baseName: method.returnType.baseName,
+                  isNullable:
+                      !method.isRequired || method.returnType.isNullable,
+                  typeArguments: method.returnType.typeArguments,
+                  associatedEnum: method.returnType.associatedEnum,
+                  associatedClass: method.returnType.associatedClass,
+                  associatedProxyApi: method.returnType.associatedProxyApi,
+                ),
+                channelName: makeChannelNameWithStrings(
+                  apiName: apiName,
+                  methodName: method.name,
+                  dartPackageName: dartPackageName,
+                ),
+                isMockHandler: false,
+                isAsynchronous: method.isAsynchronous,
+                nullHandlerExpression: '${classMemberNamePrefix}clearHandlers',
+                onCreateApiCall: (
+                  String methodName,
+                  Iterable<Parameter> parameters,
+                  Iterable<String> safeArgumentNames,
+                ) {
+                  final String nullability = method.isRequired ? '' : '?';
+                  return '($methodName ?? ${safeArgumentNames.first}.$methodName)$nullability.call(${safeArgumentNames.join(',')})';
+                },
+              );
+              builder.statements.add(cb.Code(messageHandlerSink.toString()));
+            }).statements,
+        ]),
+    );
+  }
+
+  Iterable<cb.Method> _proxyApiAttachedFieldMethods(
+    Iterable<ApiField> fields, {
+    required String apiName,
+    required String dartPackageName,
+    required String codecInstanceName,
+    required String codecName,
+  }) sync* {
+    for (final ApiField field in fields) {
+      yield cb.Method(
+        (cb.MethodBuilder builder) {
+          final String type = _addGenericTypesNullable(field.type);
+          const String instanceName = '${_varNamePrefix}instance';
+          const String identifierInstanceName =
+              '${_varNamePrefix}instanceIdentifier';
+          builder
+            ..name = '$_varNamePrefix${field.name}'
+            ..static = field.isStatic
+            ..returns = cb.refer(type)
+            ..body = cb.Block(
+              (cb.BlockBuilder builder) {
+                final StringBuffer messageCallSink = StringBuffer();
+                _writeHostMethodMessageCall(
+                  Indent(messageCallSink),
+                  channelName: makeChannelNameWithStrings(
+                    apiName: apiName,
+                    methodName: field.name,
+                    dartPackageName: dartPackageName,
+                  ),
+                  parameters: <Parameter>[
+                    if (!field.isStatic)
+                      Parameter(
+                        name: 'this',
+                        type: TypeDeclaration(
+                          baseName: apiName,
+                          isNullable: false,
+                        ),
+                      ),
+                    Parameter(
+                      name: identifierInstanceName,
+                      type: const TypeDeclaration(
+                        baseName: 'int',
+                        isNullable: false,
+                      ),
+                    ),
+                  ],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                );
+                builder.statements.addAll(<cb.Code>[
+                  if (!field.isStatic) ...<cb.Code>[
+                    cb.Code(
+                      'final $type $instanceName = $type.${classMemberNamePrefix}detached(\n'
+                      '  pigeon_binaryMessenger: pigeon_binaryMessenger,\n'
+                      '  pigeon_instanceManager: pigeon_instanceManager,\n'
+                      ');',
+                    ),
+                    cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                        '    $codecInstanceName;'),
+                    const cb.Code(
+                      'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+                    ),
+                    const cb.Code(
+                      'final int $identifierInstanceName = $_instanceManagerVarName.addDartCreatedInstance($instanceName);',
+                    ),
+                  ] else ...<cb.Code>[
+                    cb.Code(
+                      'final $type $instanceName = $type.${classMemberNamePrefix}detached();',
+                    ),
+                    cb.Code(
+                      'final $codecName $_pigeonChannelCodec = $codecName($instanceManagerClassName.instance);',
+                    ),
+                    const cb.Code(
+                      'final BinaryMessenger ${_varNamePrefix}binaryMessenger = ServicesBinding.instance.defaultBinaryMessenger;',
+                    ),
+                    const cb.Code(
+                      'final int $identifierInstanceName = $instanceManagerClassName.instance.addDartCreatedInstance($instanceName);',
+                    ),
+                  ],
+                  const cb.Code('() async {'),
+                  cb.Code(messageCallSink.toString()),
+                  const cb.Code('}();'),
+                  const cb.Code('return $instanceName;'),
+                ]);
+              },
+            );
+        },
+      );
+    }
+  }
+
+  Iterable<cb.Method> _proxyApiHostMethods(
+    Iterable<Method> methods, {
+    required String apiName,
+    required String dartPackageName,
+    required String codecInstanceName,
+    required String codecName,
+  }) sync* {
+    for (final Method method in methods) {
+      assert(method.location == ApiLocation.host);
+      yield cb.Method(
+        (cb.MethodBuilder builder) => builder
+          ..name = method.name
+          ..static = method.isStatic
+          ..modifier = cb.MethodModifier.async
+          ..docs.addAll(asDocumentationComments(
+            method.documentationComments,
+            _docCommentSpec,
+          ))
+          ..returns = _refer(method.returnType, asFuture: true)
+          ..requiredParameters.addAll(
+            method.parameters.mapIndexed(
+              (int index, NamedType parameter) => cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = _getParameterName(index, parameter)
+                  ..type = cb.refer(
+                    _addGenericTypesNullable(parameter.type),
+                  ),
+              ),
+            ),
+          )
+          ..optionalParameters.addAll(<cb.Parameter>[
+            if (method.isStatic) ...<cb.Parameter>[
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = '${classMemberNamePrefix}binaryMessenger'
+                  ..type = cb.refer('BinaryMessenger?')
+                  ..named = true,
+              ),
+              cb.Parameter(
+                (cb.ParameterBuilder builder) => builder
+                  ..name = _instanceManagerVarName
+                  ..type = cb.refer('$instanceManagerClassName?'),
+              ),
+            ],
+          ])
+          ..body = cb.Block(
+            (cb.BlockBuilder builder) {
+              final StringBuffer messageCallSink = StringBuffer();
+              _writeHostMethodMessageCall(
+                Indent(messageCallSink),
+                channelName: makeChannelNameWithStrings(
+                  apiName: apiName,
+                  methodName: method.name,
+                  dartPackageName: dartPackageName,
+                ),
+                parameters: <Parameter>[
+                  if (!method.isStatic)
+                    Parameter(
+                      name: 'this',
+                      type: TypeDeclaration(
+                        baseName: apiName,
+                        isNullable: false,
+                      ),
+                    ),
+                  ...method.parameters,
+                ],
+                returnType: method.returnType,
+              );
+              builder.statements.addAll(<cb.Code>[
+                if (!method.isStatic)
+                  cb.Code('final $codecName $_pigeonChannelCodec =\n'
+                      '    $codecInstanceName;')
+                else
+                  cb.Code(
+                    'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
+                  ),
+                const cb.Code(
+                  'final BinaryMessenger? ${_varNamePrefix}binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+                ),
+                cb.Code(messageCallSink.toString()),
+              ]);
+            },
+          ),
+      );
+    }
+  }
+
+  cb.Method _proxyApiCopyMethod({
+    required Iterable<Method> flutterMethods,
+    required Iterable<Method> superClassFlutterMethods,
+    required String apiName,
+    required Iterable<ApiField> unattachedFields,
+    required Iterable<AstProxyApi> interfacesApis,
+  }) {
+    return cb.Method(
+      (cb.MethodBuilder builder) => builder
+        ..name = '${classMemberNamePrefix}copy'
+        ..returns = cb.refer(apiName)
+        ..annotations.add(cb.refer('override'))
+        ..body = cb.Block.of(<cb.Code>[
+          cb
+              .refer('$apiName.${classMemberNamePrefix}detached')
+              .call(
+                <cb.Expression>[],
+                <String, cb.Expression>{
+                  '${classMemberNamePrefix}binaryMessenger':
+                      cb.refer('${classMemberNamePrefix}binaryMessenger'),
+                  _instanceManagerVarName: cb.refer(_instanceManagerVarName),
+                  for (final ApiField field in unattachedFields)
+                    field.name: cb.refer(field.name),
+                  for (final Method method in superClassFlutterMethods)
+                    method.name: cb.refer(method.name),
+                  for (final AstProxyApi proxyApi in interfacesApis)
+                    for (final Method method in proxyApi.methods)
+                      method.name: cb.refer(method.name),
+                  for (final Method method in flutterMethods)
+                    method.name: cb.refer(method.name),
+                },
+              )
+              .returned
+              .statement,
+        ]),
+    );
+  }
 }
 
 cb.Reference _refer(TypeDeclaration type, {bool asFuture = false}) {

From 2dac15de2f86dd19d87294cd98263d5628b03d3b Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 31 Jan 2024 17:03:17 -0500
Subject: [PATCH 19/32] add proxy api base class

---
 packages/pigeon/lib/dart_generator.dart | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 1dc1b54f2d45..a17c387f46be 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -459,6 +459,8 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     Indent indent, {
     required String dartPackageName,
   }) {
+    indent.writeln(proxyApiBaseClass);
+
     indent.writeln(
       instanceManagerTemplate(
         proxyApiBaseClassName: '${classMemberNamePrefix}ProxyApiBaseClass',

From 36bbca1d23da40610b87d2b10c1bcf8e0f5e8224 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 12:30:02 -0500
Subject: [PATCH 20/32] add documentation

---
 packages/pigeon/lib/dart/templates.dart |  8 ++++
 packages/pigeon/lib/dart_generator.dart | 58 +++++++++++++++++++++++--
 2 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index fe56d16f4fbe..14d25d57dc94 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -319,6 +319,9 @@ class _$apiName {
 }''';
 }
 
+/// The base class for all ProxyApis.
+///
+/// All Dart classes generated as a ProxyApi extends this one.
 const String proxyApiBaseClass = '''
 /// An immutable object that serves as the base class for all ProxyApis and
 /// can provide functional copies of itself.
@@ -355,6 +358,11 @@ abstract class $_proxyApiBaseClassName {
 }
 ''';
 
+/// The base codec for ProxyApis.
+///
+/// All generated Dart proxy apis should use this codec or extend it. This codec
+/// adds support to convert instances to their corresponding identifier from an
+/// `InstanceManager` and vice versa.
 const String proxyApiBaseCodec = '''
 class $_proxyApiCodecName extends StandardMessageCodec {
  const $_proxyApiCodecName(this.instanceManager);
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index a17c387f46be..a26c27f66599 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -597,7 +597,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           apiName: api.name,
         ))
         ..fields.addAll(_proxyApiInterfaceApiFields(interfacesApis))
-        ..fields.addAll(_proxyApiattachedFields(api.attachedFields))
+        ..fields.addAll(_proxyApiAttachedFields(api.attachedFields))
         ..methods.add(
           _proxyApiSetUpMessageHandlerMethod(
             flutterMethods: api.flutterMethods,
@@ -1000,6 +1000,8 @@ if (${_varNamePrefix}replyList == null) {
     return 'api.$methodName(${safeArgumentNames.join(', ')})';
   }
 
+  /// Converts Constructors from the pigeon AST to a `code_builder` Constructor
+  /// for a ProxyApi.
   Iterable<cb.Constructor> _proxyApiConstructors(
     Iterable<Constructor> constructors, {
     required String apiName,
@@ -1125,7 +1127,7 @@ if (${_varNamePrefix}replyList == null) {
   /// This constructor doesn't include a host method call to create a new native
   /// class instance. It is mainly used when the native side once to create a
   /// Dart instance and when the `InstanceManager` wants to create a copy for
-  /// garbage collection.
+  /// automatic garbage collection.
   cb.Constructor _proxyApiDetachedConstructor({
     required String apiName,
     required AstProxyApi? superClassApi,
@@ -1180,6 +1182,7 @@ if (${_varNamePrefix}replyList == null) {
     );
   }
 
+  /// A private Field of the base codec.
   cb.Field _proxyApiCodecInstanceField({
     required String codecInstanceName,
     required String codecName,
@@ -1194,8 +1197,11 @@ if (${_varNamePrefix}replyList == null) {
     );
   }
 
+  /// Converts unattached constructors from the pigeon AST to `code_builder`
+  /// Fields.
   Iterable<cb.Field> _proxyApiUnattachedFields(
-      Iterable<ApiField> fields) sync* {
+    Iterable<ApiField> fields,
+  ) sync* {
     for (final ApiField field in fields) {
       yield cb.Field(
         (cb.FieldBuilder builder) => builder
@@ -1210,6 +1216,10 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
+  /// Converts Flutter methods from the pigeon AST to `code_builder` Fields.
+  ///
+  /// Flutter methods of a ProxyApi are set as an anonymous function of a class
+  /// instance, so this converts methods to a `Function` type field instance.
   Iterable<cb.Field> _proxyApiFlutterMethodFields(
     Iterable<Method> methods, {
     required String apiName,
@@ -1268,6 +1278,14 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
+  /// Converts the Flutter methods from the pigeon AST to `code_builder` Fields.
+  ///
+  /// Flutter methods of a ProxyApi are set as an anonymous function of a class
+  /// instance, so this converts methods to a `Function` type field instance.
+  ///
+  /// This is similar to [_proxyApiFlutterMethodFields] except all the methods are
+  /// inherited from apis that are being implemented (following the `implements`
+  /// keyword).
   Iterable<cb.Field> _proxyApiInterfaceApiFields(
     Iterable<AstProxyApi> apis,
   ) sync* {
@@ -1307,7 +1325,17 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
-  Iterable<cb.Field> _proxyApiattachedFields(Iterable<ApiField> fields) sync* {
+  /// Converts attached Fields from the pigeon AST to `code_builder` Field.
+  ///
+  /// Attached fields are set lazily by calling a private method that returns
+  /// it.
+  ///
+  /// Example Output:
+  ///
+  /// ```dart
+  /// final MyOtherProxyApiClass value = _pigeon_value();
+  /// ```
+  Iterable<cb.Field> _proxyApiAttachedFields(Iterable<ApiField> fields) sync* {
     for (final ApiField field in fields) {
       yield cb.Field(
         (cb.FieldBuilder builder) => builder
@@ -1325,6 +1353,14 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
+  /// Creates the static `setUpMessageHandlers` method for a ProxyApi.
+  ///
+  /// This method handles setting the message handler for every un-inherited
+  /// Flutter method.
+  ///
+  /// This also adds a handler to receive a call from the platform to
+  /// instantiate a new Dart instance if [hasCallbackConstructor] is set to
+  /// true.
   cb.Method _proxyApiSetUpMessageHandlerMethod({
     required Iterable<Method> flutterMethods,
     required String apiName,
@@ -1513,6 +1549,11 @@ if (${_varNamePrefix}replyList == null) {
     );
   }
 
+  /// Converts attached fields from the pigeon AST to `code_builder` fields.
+  ///
+  /// These private methods are used to lazily instantiate attached fields. The
+  /// instance is created and returned synchronously while the native instance
+  /// is created synchronously. This is similar to how constructors work.
   Iterable<cb.Method> _proxyApiAttachedFieldMethods(
     Iterable<ApiField> fields, {
     required String apiName,
@@ -1602,6 +1643,10 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
+  /// Converts host methods from pigeon AST to `code_builder` AST.
+  ///
+  /// This creates methods like a HostApi except that it includes the calling
+  /// instance if the method is not static.
   Iterable<cb.Method> _proxyApiHostMethods(
     Iterable<Method> methods, {
     required String apiName,
@@ -1689,6 +1734,11 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
+  /// Creates the copy method for a ProxyApi.
+  ///
+  /// This method returns a copy of the instance with all the Flutter methods
+  /// and unattached fields passed to the new instance. This method is inherited
+  /// from the base ProxyApi class.
   cb.Method _proxyApiCopyMethod({
     required Iterable<Method> flutterMethods,
     required Iterable<Method> superClassFlutterMethods,

From afa62e8756accc48350aa9a83f45252e72807c26 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 13:36:33 -0500
Subject: [PATCH 21/32] add tests and some minor validatation improvements

---
 packages/pigeon/lib/dart/templates.dart |  4 ++
 packages/pigeon/lib/dart_generator.dart | 66 ++++++++++++++++---------
 packages/pigeon/lib/pigeon_lib.dart     |  8 +--
 3 files changed, 52 insertions(+), 26 deletions(-)

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index 14d25d57dc94..3459fcd5c242 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -1,3 +1,7 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import '../generator_tools.dart';
 
 /// Creates the `InstanceManager` with the passed string values.
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index a26c27f66599..d00cfea4c2ee 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -520,9 +520,9 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     final Set<AstProxyApi> interfacesApis = recursiveFindAllInterfaceApis(api);
 
     // All methods inherited from interfaces and the interfaces of interfaces.
-    final List<Method> interfacesMethods = <Method>[];
+    final List<Method> flutterMethodsFromInterfaces = <Method>[];
     for (final AstProxyApi proxyApi in interfacesApis) {
-      interfacesMethods.addAll(proxyApi.methods);
+      flutterMethodsFromInterfaces.addAll(proxyApi.methods);
     }
 
     // A list of Flutter methods inherited from the ProxyApi that this ProxyApi
@@ -531,17 +531,17 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     //
     // This also includes methods that super classes inherited from interfaces
     // with `implements`.
-    final List<Method> superClassFlutterMethods = <Method>[];
+    final List<Method> flutterMethodsFromSuperClasses = <Method>[];
     for (final AstProxyApi proxyApi in superClassApisChain.reversed) {
-      superClassFlutterMethods.addAll(proxyApi.flutterMethods);
+      flutterMethodsFromSuperClasses.addAll(proxyApi.flutterMethods);
     }
     if (api.superClass != null) {
-      final Set<AstProxyApi> superClassInterfacesApis =
+      final Set<AstProxyApi> interfaceApisFromSuperClasses =
           recursiveFindAllInterfaceApis(
         api.superClass!.associatedProxyApi!,
       );
-      for (final AstProxyApi proxyApi in superClassInterfacesApis) {
-        superClassFlutterMethods.addAll(proxyApi.methods);
+      for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
+        flutterMethodsFromSuperClasses.addAll(proxyApi.methods);
       }
     }
 
@@ -568,18 +568,18 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           codecInstanceName: codecInstanceName,
           superClassApi: api.superClass?.associatedProxyApi,
           unattachedFields: api.unattachedFields,
-          declaredAndInheritedFlutterMethods: superClassFlutterMethods
-              .followedBy(interfacesMethods)
-              .followedBy(api.flutterMethods),
+          flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+          flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+          declaredFlutterMethods: api.flutterMethods,
         ))
         ..constructors.add(
           _proxyApiDetachedConstructor(
             apiName: api.name,
             superClassApi: api.superClass?.associatedProxyApi,
             unattachedFields: api.unattachedFields,
-            declaredAndInheritedFlutterMethods: superClassFlutterMethods
-                .followedBy(interfacesMethods)
-                .followedBy(api.flutterMethods),
+            flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
+            flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+            declaredFlutterMethods: api.flutterMethods,
           ),
         )
         ..fields.addAll(<cb.Field>[
@@ -606,8 +606,8 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
             codecName: codecName,
             unattachedFields: api.unattachedFields,
             hasCallbackConstructor: api.methods
-                .followedBy(superClassFlutterMethods)
-                .followedBy(interfacesMethods)
+                .followedBy(flutterMethodsFromSuperClasses)
+                .followedBy(flutterMethodsFromInterfaces)
                 .every((Method method) => !method.isRequired),
           ),
         )
@@ -629,7 +629,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
         ))
         ..methods.add(_proxyApiCopyMethod(
           flutterMethods: api.flutterMethods,
-          superClassFlutterMethods: superClassFlutterMethods,
+          flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
           apiName: api.name,
           unattachedFields: api.unattachedFields,
           interfacesApis: interfacesApis,
@@ -1010,7 +1010,9 @@ if (${_varNamePrefix}replyList == null) {
     required String codecInstanceName,
     required AstProxyApi? superClassApi,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> declaredAndInheritedFlutterMethods,
+    required Iterable<Method> flutterMethodsFromSuperClasses,
+    required Iterable<Method> flutterMethodsFromInterfaces,
+    required Iterable<Method> declaredFlutterMethods,
   }) sync* {
     final cb.Parameter binaryMessengerParameter = cb.Parameter(
       (cb.ParameterBuilder builder) => builder
@@ -1052,7 +1054,7 @@ if (${_varNamePrefix}replyList == null) {
                       ..toThis = true
                       ..required = !field.type.isNullable,
                   ),
-                for (final Method method in declaredAndInheritedFlutterMethods)
+                for (final Method method in flutterMethodsFromSuperClasses)
                   cb.Parameter(
                     (cb.ParameterBuilder builder) => builder
                       ..name = method.name
@@ -1060,6 +1062,15 @@ if (${_varNamePrefix}replyList == null) {
                       ..toSuper = true
                       ..required = method.isRequired,
                   ),
+                for (final Method method in flutterMethodsFromInterfaces
+                    .followedBy(declaredFlutterMethods))
+                  cb.Parameter(
+                    (cb.ParameterBuilder builder) => builder
+                      ..name = method.name
+                      ..named = true
+                      ..toThis = true
+                      ..required = method.isRequired,
+                  ),
                 ...constructor.parameters.mapIndexed(
                   (int index, NamedType parameter) => cb.Parameter(
                     (cb.ParameterBuilder builder) => builder
@@ -1132,7 +1143,9 @@ if (${_varNamePrefix}replyList == null) {
     required String apiName,
     required AstProxyApi? superClassApi,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<Method> declaredAndInheritedFlutterMethods,
+    required Iterable<Method> flutterMethodsFromSuperClasses,
+    required Iterable<Method> flutterMethodsFromInterfaces,
+    required Iterable<Method> declaredFlutterMethods,
   }) {
     final cb.Parameter binaryMessengerParameter = cb.Parameter(
       (cb.ParameterBuilder builder) => builder
@@ -1166,7 +1179,7 @@ if (${_varNamePrefix}replyList == null) {
                 ..toThis = true
                 ..required = !field.type.isNullable,
             ),
-          for (final Method method in declaredAndInheritedFlutterMethods)
+          for (final Method method in flutterMethodsFromSuperClasses)
             cb.Parameter(
               (cb.ParameterBuilder builder) => builder
                 ..name = method.name
@@ -1174,6 +1187,15 @@ if (${_varNamePrefix}replyList == null) {
                 ..toSuper = true
                 ..required = method.isRequired,
             ),
+          for (final Method method in flutterMethodsFromInterfaces
+              .followedBy(declaredFlutterMethods))
+            cb.Parameter(
+              (cb.ParameterBuilder builder) => builder
+                ..name = method.name
+                ..named = true
+                ..toThis = true
+                ..required = method.isRequired,
+            ),
         ])
         ..initializers.addAll(<cb.Code>[
           if (superClassApi != null)
@@ -1741,7 +1763,7 @@ if (${_varNamePrefix}replyList == null) {
   /// from the base ProxyApi class.
   cb.Method _proxyApiCopyMethod({
     required Iterable<Method> flutterMethods,
-    required Iterable<Method> superClassFlutterMethods,
+    required Iterable<Method> flutterMethodsFromSuperClasses,
     required String apiName,
     required Iterable<ApiField> unattachedFields,
     required Iterable<AstProxyApi> interfacesApis,
@@ -1762,7 +1784,7 @@ if (${_varNamePrefix}replyList == null) {
                   _instanceManagerVarName: cb.refer(_instanceManagerVarName),
                   for (final ApiField field in unattachedFields)
                     field.name: cb.refer(field.name),
-                  for (final Method method in superClassFlutterMethods)
+                  for (final Method method in flutterMethodsFromSuperClasses)
                     method.name: cb.refer(method.name),
                   for (final AstProxyApi proxyApi in interfacesApis)
                     for (final Method method in proxyApi.methods)
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 187aa3466b2a..65cabf04ef37 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -1029,10 +1029,10 @@ List<Error> _validateProxyApi(
     }
 
     // Validate this api isn't used as an interface and contains anything except
-    // Flutter methods.
-    final bool isValidInterfaceProxyApi = api.hostMethods.isEmpty &&
-        api.constructors.isEmpty &&
-        api.fields.isEmpty;
+    // Flutter methods or a static host method.
+    final bool isValidInterfaceProxyApi = api.constructors.isEmpty &&
+        api.fields.where((ApiField field) => !field.isStatic).isEmpty &&
+        api.hostMethods.where((Method method) => !method.isStatic).isEmpty;
     if (!isValidInterfaceProxyApi) {
       final Iterable<String> interfaceNames = proxyApi.interfaces.map(
         (TypeDeclaration type) => type.baseName,

From 1cd4d95b65661863f11270005801882792a33806 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 13:43:35 -0500
Subject: [PATCH 22/32] add tests actually

---
 packages/pigeon/pigeons/proxy_api_tests.dart  |  471 ++++++++
 packages/pigeon/test/dart/proxy_api_test.dart | 1014 +++++++++++++++++
 2 files changed, 1485 insertions(+)
 create mode 100644 packages/pigeon/pigeons/proxy_api_tests.dart
 create mode 100644 packages/pigeon/test/dart/proxy_api_test.dart

diff --git a/packages/pigeon/pigeons/proxy_api_tests.dart b/packages/pigeon/pigeons/proxy_api_tests.dart
new file mode 100644
index 000000000000..c09eebd8239d
--- /dev/null
+++ b/packages/pigeon/pigeons/proxy_api_tests.dart
@@ -0,0 +1,471 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:pigeon/pigeon.dart';
+// TODO(bparrishMines): Remove this import when ProxyApi has an implementation
+// for at least one host language.
+import 'package:pigeon/pigeon_lib.dart';
+
+enum AnEnum {
+  one,
+  two,
+  three,
+}
+
+/// The core interface that each host language plugin must implement in
+/// platform_test integration tests.
+@ProxyApi()
+abstract class ProxyApiTestClass extends ProxyApiSuperClass
+    implements ProxyApiInterface {
+  ProxyApiTestClass(
+    // ignore: avoid_unused_constructor_parameters
+    bool boolParam,
+    // ignore: avoid_unused_constructor_parameters
+    int intParam,
+    // ignore: avoid_unused_constructor_parameters
+    double doubleParam,
+    // ignore: avoid_unused_constructor_parameters
+    String stringParam,
+    // ignore: avoid_unused_constructor_parameters
+    Uint8List aUint8ListParam,
+    // ignore: avoid_unused_constructor_parameters
+    List<Object?> listParam,
+    // ignore: avoid_unused_constructor_parameters
+    Map<String?, Object?> mapParam,
+    // ignore: avoid_unused_constructor_parameters
+    AnEnum enumParam,
+    // ignore: avoid_unused_constructor_parameters
+    ProxyApiSuperClass proxyApiParam,
+    // ignore: avoid_unused_constructor_parameters
+    bool? nullableBoolParam,
+    // ignore: avoid_unused_constructor_parameters
+    int? nullableIntParam,
+    // ignore: avoid_unused_constructor_parameters
+    double? nullableDoubleParam,
+    // ignore: avoid_unused_constructor_parameters
+    String? nullableStringParam,
+    // ignore: avoid_unused_constructor_parameters
+    Uint8List? nullableUint8ListParam,
+    // ignore: avoid_unused_constructor_parameters
+    List<Object?>? nullableListParam,
+    // ignore: avoid_unused_constructor_parameters
+    Map<String?, Object?>? nullableMapParam,
+    // ignore: avoid_unused_constructor_parameters
+    AnEnum? nullableEnumParam,
+    // ignore: avoid_unused_constructor_parameters
+    ProxyApiSuperClass? nullableProxyApiParam,
+  );
+
+  late bool aBool;
+  late int anInt;
+  late double aDouble;
+  late String aString;
+  late Uint8List aUint8List;
+  late List<Object?> aList;
+  late Map<String?, Object?> aMap;
+  late AnEnum anEnum;
+  late ProxyApiSuperClass aProxyApi;
+
+  late bool? aNullableBool;
+  late int? aNullableInt;
+  late double? aNullableDouble;
+  late String? aNullableString;
+  late Uint8List? aNullableUint8List;
+  late List<Object?>? aNullableList;
+  late Map<String?, Object?>? aNullableMap;
+  late AnEnum? aNullableEnum;
+  late ProxyApiSuperClass? aNullableProxyApi;
+
+  @attached
+  late ProxyApiSuperClass attachedField;
+
+  @static
+  late ProxyApiSuperClass staticAttachedField;
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic calling.
+  late void Function()? flutterNoop;
+
+  /// Responds with an error from an async function returning a value.
+  late Object? Function()? flutterThrowError;
+
+  /// Responds with an error from an async void function.
+  late void Function()? flutterThrowErrorFromVoid;
+
+  // ========== Non-nullable argument/return type tests ==========
+
+  /// Returns the passed boolean, to test serialization and deserialization.
+  late bool Function(bool aBool)? flutterEchoBool;
+
+  /// Returns the passed int, to test serialization and deserialization.
+  late int Function(int anInt)? flutterEchoInt;
+
+  /// Returns the passed double, to test serialization and deserialization.
+  late double Function(double aDouble)? flutterEchoDouble;
+
+  /// Returns the passed string, to test serialization and deserialization.
+  late String Function(String aString)? flutterEchoString;
+
+  /// Returns the passed byte list, to test serialization and deserialization.
+  late Uint8List Function(Uint8List aList)? flutterEchoUint8List;
+
+  /// Returns the passed list, to test serialization and deserialization.
+  late List<Object?> Function(List<Object?> aList)? flutterEchoList;
+
+  /// Returns the passed list with ProxyApis, to test serialization and
+  /// deserialization.
+  late List<ProxyApiTestClass?> Function(List<ProxyApiTestClass?> aList)?
+      flutterEchoProxyApiList;
+
+  /// Returns the passed map, to test serialization and deserialization.
+  late Map<String?, Object?> Function(Map<String?, Object?> aMap)?
+      flutterEchoMap;
+
+  /// Returns the passed map with ProxyApis, to test serialization and
+  /// deserialization.
+  late Map<String?, ProxyApiTestClass?> Function(
+      Map<String?, ProxyApiTestClass?> aMap)? flutterEchoProxyApiMap;
+
+  /// Returns the passed enum to test serialization and deserialization.
+  late AnEnum Function(AnEnum anEnum)? flutterEchoEnum;
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  late ProxyApiSuperClass Function(ProxyApiSuperClass aProxyApi)?
+      flutterEchoProxyApi;
+
+  // ========== Nullable argument/return type tests ==========
+
+  /// Returns the passed boolean, to test serialization and deserialization.
+  late bool? Function(bool? aBool)? flutterEchoNullableBool;
+
+  /// Returns the passed int, to test serialization and deserialization.
+  late int? Function(int? anInt)? flutterEchoNullableInt;
+
+  /// Returns the passed double, to test serialization and deserialization.
+  late double? Function(double? aDouble)? flutterEchoNullableDouble;
+
+  /// Returns the passed string, to test serialization and deserialization.
+  late String? Function(String? aString)? flutterEchoNullableString;
+
+  /// Returns the passed byte list, to test serialization and deserialization.
+  late Uint8List? Function(Uint8List? aList)? flutterEchoNullableUint8List;
+
+  /// Returns the passed list, to test serialization and deserialization.
+  late List<Object?>? Function(List<Object?>? aList)? flutterEchoNullableList;
+
+  /// Returns the passed map, to test serialization and deserialization.
+  late Map<String?, Object?>? Function(Map<String?, Object?>? aMap)?
+      flutterEchoNullableMap;
+
+  /// Returns the passed enum to test serialization and deserialization.
+  late AnEnum? Function(AnEnum? anEnum)? flutterEchoNullableEnum;
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  late ProxyApiSuperClass? Function(ProxyApiSuperClass? aProxyApi)?
+      flutterEchoNullableProxyApi;
+
+  // ========== Async tests ==========
+  // These are minimal since async FlutterApi only changes Dart generation.
+  // Currently they aren't integration tested, but having them here ensures
+  // analysis coverage.
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic asynchronous calling.
+  @async
+  late void Function()? flutterNoopAsync;
+
+  /// Returns the passed in generic Object asynchronously.
+  @async
+  late String Function(String aString)? flutterEchoAsyncString;
+
+  // ========== Synchronous host method tests ==========
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic calling.
+  void noop();
+
+  /// Returns an error, to test error handling.
+  Object? throwError();
+
+  /// Returns an error from a void function, to test error handling.
+  void throwErrorFromVoid();
+
+  /// Returns a Flutter error, to test error handling.
+  Object? throwFlutterError();
+
+  /// Returns passed in int.
+  int echoInt(int anInt);
+
+  /// Returns passed in double.
+  double echoDouble(double aDouble);
+
+  /// Returns the passed in boolean.
+  bool echoBool(bool aBool);
+
+  /// Returns the passed in string.
+  String echoString(String aString);
+
+  /// Returns the passed in Uint8List.
+  Uint8List echoUint8List(Uint8List aUint8List);
+
+  /// Returns the passed in generic Object.
+  Object echoObject(Object anObject);
+
+  /// Returns the passed list, to test serialization and deserialization.
+  List<Object?> echoList(List<Object?> aList);
+
+  /// Returns the passed list with ProxyApis, to test serialization and
+  /// deserialization.
+  List<ProxyApiTestClass> echoProxyApiList(
+    List<ProxyApiTestClass> aList,
+  );
+
+  /// Returns the passed map, to test serialization and deserialization.
+  Map<String?, Object?> echoMap(Map<String?, Object?> aMap);
+
+  /// Returns the passed map with ProxyApis, to test serialization and
+  /// deserialization.
+  Map<String, ProxyApiTestClass> echoProxyApiMap(
+    Map<String, ProxyApiTestClass> aMap,
+  );
+
+  /// Returns the passed enum to test serialization and deserialization.
+  AnEnum echoEnum(AnEnum anEnum);
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  ProxyApiSuperClass echoProxyApi(ProxyApiSuperClass aProxyApi);
+
+  // ========== Synchronous host nullable method tests ==========
+
+  /// Returns passed in int.
+  int? echoNullableInt(int? aNullableInt);
+
+  /// Returns passed in double.
+  double? echoNullableDouble(double? aNullableDouble);
+
+  /// Returns the passed in boolean.
+  bool? echoNullableBool(bool? aNullableBool);
+
+  /// Returns the passed in string.
+  String? echoNullableString(String? aNullableString);
+
+  /// Returns the passed in Uint8List.
+  Uint8List? echoNullableUint8List(Uint8List? aNullableUint8List);
+
+  /// Returns the passed in generic Object.
+  Object? echoNullableObject(Object? aNullableObject);
+
+  /// Returns the passed list, to test serialization and deserialization.
+  List<Object?>? echoNullableList(List<Object?>? aNullableList);
+
+  /// Returns the passed map, to test serialization and deserialization.
+  Map<String?, Object?>? echoNullableMap(Map<String?, Object?>? aNullableMap);
+
+  AnEnum? echoNullableEnum(AnEnum? aNullableEnum);
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  ProxyApiSuperClass? echoNullableProxyApi(
+    ProxyApiSuperClass? aNullableProxyApi,
+  );
+
+  // ========== Asynchronous method tests ==========
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic asynchronous calling.
+  @async
+  void noopAsync();
+
+  /// Returns passed in int asynchronously.
+  @async
+  int echoAsyncInt(int anInt);
+
+  /// Returns passed in double asynchronously.
+  @async
+  double echoAsyncDouble(double aDouble);
+
+  /// Returns the passed in boolean asynchronously.
+  @async
+  bool echoAsyncBool(bool aBool);
+
+  /// Returns the passed string asynchronously.
+  @async
+  String echoAsyncString(String aString);
+
+  /// Returns the passed in Uint8List asynchronously.
+  @async
+  Uint8List echoAsyncUint8List(Uint8List aUint8List);
+
+  /// Returns the passed in generic Object asynchronously.
+  @async
+  Object echoAsyncObject(Object anObject);
+
+  /// Returns the passed list, to test asynchronous serialization and deserialization.
+  @async
+  List<Object?> echoAsyncList(List<Object?> aList);
+
+  /// Returns the passed map, to test asynchronous serialization and deserialization.
+  @async
+  Map<String?, Object?> echoAsyncMap(Map<String?, Object?> aMap);
+
+  /// Returns the passed enum, to test asynchronous serialization and deserialization.
+  @async
+  AnEnum echoAsyncEnum(AnEnum anEnum);
+
+  /// Responds with an error from an async function returning a value.
+  @async
+  Object? throwAsyncError();
+
+  /// Responds with an error from an async void function.
+  @async
+  void throwAsyncErrorFromVoid();
+
+  /// Responds with a Flutter error from an async function returning a value.
+  @async
+  Object? throwAsyncFlutterError();
+
+  /// Returns passed in int asynchronously.
+  @async
+  int? echoAsyncNullableInt(int? anInt);
+
+  /// Returns passed in double asynchronously.
+  @async
+  double? echoAsyncNullableDouble(double? aDouble);
+
+  /// Returns the passed in boolean asynchronously.
+  @async
+  bool? echoAsyncNullableBool(bool? aBool);
+
+  /// Returns the passed string asynchronously.
+  @async
+  String? echoAsyncNullableString(String? aString);
+
+  /// Returns the passed in Uint8List asynchronously.
+  @async
+  Uint8List? echoAsyncNullableUint8List(Uint8List? aUint8List);
+
+  /// Returns the passed in generic Object asynchronously.
+  @async
+  Object? echoAsyncNullableObject(Object? anObject);
+
+  /// Returns the passed list, to test asynchronous serialization and deserialization.
+  @async
+  List<Object?>? echoAsyncNullableList(List<Object?>? aList);
+
+  /// Returns the passed map, to test asynchronous serialization and deserialization.
+  @async
+  Map<String?, Object?>? echoAsyncNullableMap(Map<String?, Object?>? aMap);
+
+  /// Returns the passed enum, to test asynchronous serialization and deserialization.
+  @async
+  AnEnum? echoAsyncNullableEnum(AnEnum? anEnum);
+
+  // ========== Static method test ==========
+
+  @static
+  void staticNoop();
+
+  @static
+  String echoStaticString(String aString);
+
+  @static
+  @async
+  void staticAsyncNoop();
+
+  // ========== Flutter methods test wrappers ==========
+
+  @async
+  void callFlutterNoop();
+
+  @async
+  Object? callFlutterThrowError();
+
+  @async
+  void callFlutterThrowErrorFromVoid();
+
+  @async
+  bool callFlutterEchoBool(bool aBool);
+
+  @async
+  int callFlutterEchoInt(int anInt);
+
+  @async
+  double callFlutterEchoDouble(double aDouble);
+
+  @async
+  String callFlutterEchoString(String aString);
+
+  @async
+  Uint8List callFlutterEchoUint8List(Uint8List aUint8List);
+
+  @async
+  List<Object?> callFlutterEchoList(List<Object?> aList);
+
+  @async
+  List<ProxyApiTestClass?> callFlutterEchoProxyApiList(
+      List<ProxyApiTestClass?> aList);
+
+  @async
+  Map<String?, Object?> callFlutterEchoMap(Map<String?, Object?> aMap);
+
+  @async
+  Map<String?, ProxyApiTestClass?> callFlutterEchoProxyApiMap(
+      Map<String?, ProxyApiTestClass?> aMap);
+
+  @async
+  AnEnum callFlutterEchoEnum(AnEnum anEnum);
+
+  @async
+  ProxyApiSuperClass callFlutterEchoProxyApi(ProxyApiSuperClass aProxyApi);
+
+  @async
+  bool? callFlutterEchoNullableBool(bool? aBool);
+
+  @async
+  int? callFlutterEchoNullableInt(int? anInt);
+
+  @async
+  double? callFlutterEchoNullableDouble(double? aDouble);
+
+  @async
+  String? callFlutterEchoNullableString(String? aString);
+
+  @async
+  Uint8List? callFlutterEchoNullableUint8List(Uint8List? aUint8List);
+
+  @async
+  List<Object?>? callFlutterEchoNullableList(List<Object?>? aList);
+
+  @async
+  Map<String?, Object?>? callFlutterEchoNullableMap(
+    Map<String?, Object?>? aMap,
+  );
+
+  @async
+  AnEnum? callFlutterEchoNullableEnum(AnEnum? anEnum);
+
+  @async
+  ProxyApiSuperClass? callFlutterEchoNullableProxyApi(
+    ProxyApiSuperClass? aProxyApi,
+  );
+
+  @async
+  void callFlutterNoopAsync();
+
+  @async
+  String callFlutterEchoAsyncString(String aString);
+}
+
+/// ProxyApi to serve as a super class to the core ProxyApi interface.
+@ProxyApi()
+abstract class ProxyApiSuperClass {
+  ProxyApiSuperClass();
+
+  void aSuperMethod();
+}
+
+/// ProxyApi to serve as an interface to the core ProxyApi interface.
+@ProxyApi()
+abstract class ProxyApiInterface {
+  late void Function()? anInterfaceMethod;
+}
diff --git a/packages/pigeon/test/dart/proxy_api_test.dart b/packages/pigeon/test/dart/proxy_api_test.dart
new file mode 100644
index 000000000000..081b3ab843bd
--- /dev/null
+++ b/packages/pigeon/test/dart/proxy_api_test.dart
@@ -0,0 +1,1014 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:pigeon/ast.dart';
+import 'package:pigeon/dart_generator.dart';
+import 'package:test/test.dart';
+
+const String DEFAULT_PACKAGE_NAME = 'test_package';
+
+void main() {
+  group('ProxyApi', () {
+    test('one api', () {
+      final Root root = Root(apis: <Api>[
+        AstProxyApi(name: 'Api', constructors: <Constructor>[
+          Constructor(name: 'name', parameters: <Parameter>[
+            Parameter(
+              type: const TypeDeclaration(
+                baseName: 'Input',
+                isNullable: false,
+              ),
+              name: 'input',
+            ),
+          ]),
+        ], fields: <ApiField>[
+          ApiField(
+            name: 'someField',
+            type: const TypeDeclaration(
+              baseName: 'int',
+              isNullable: false,
+            ),
+          )
+        ], methods: <Method>[
+          Method(
+            name: 'doSomething',
+            location: ApiLocation.host,
+            parameters: <Parameter>[
+              Parameter(
+                type: const TypeDeclaration(
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
+                name: 'input',
+              )
+            ],
+            returnType: const TypeDeclaration(
+              baseName: 'String',
+              isNullable: false,
+            ),
+          ),
+          Method(
+            name: 'doSomethingElse',
+            location: ApiLocation.flutter,
+            parameters: <Parameter>[
+              Parameter(
+                type: const TypeDeclaration(
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
+                name: 'input',
+              )
+            ],
+            returnType: const TypeDeclaration(
+              baseName: 'String',
+              isNullable: false,
+            ),
+            isRequired: false,
+          ),
+        ])
+      ], classes: <Class>[], enums: <Enum>[]);
+      final StringBuffer sink = StringBuffer();
+      const DartGenerator generator = DartGenerator();
+      generator.generate(
+        const DartOptions(),
+        root,
+        sink,
+        dartPackageName: DEFAULT_PACKAGE_NAME,
+      );
+      final String code = sink.toString();
+      final String collapsedCode = _collapseNewlineAndIndentation(code);
+
+      // Instance Manager
+      expect(code, contains(r'class Pigeon_InstanceManager'));
+      expect(code, contains(r'class _Pigeon_InstanceManagerApi'));
+
+      // Base Api class
+      expect(
+        code,
+        contains(r'abstract class Pigeon_ProxyApiBaseClass'),
+      );
+
+      // Codec and class
+      expect(code, contains('class _Pigeon_ProxyApiBaseCodec'));
+      expect(code, contains(r'class Api extends Pigeon_ProxyApiBaseClass'));
+
+      // Constructors
+      expect(
+        collapsedCode,
+        contains(
+          r'Api.name({ super.pigeon_binaryMessenger, super.pigeon_instanceManager, required this.someField, this.doSomethingElse, required Input input, })',
+        ),
+      );
+      expect(
+        code,
+        contains(
+          r'Api.pigeon_detached',
+        ),
+      );
+
+      // Field
+      expect(code, contains('final int someField;'));
+
+      // Dart -> Host method
+      expect(code, contains('Future<String> doSomething(Input input)'));
+
+      // Host -> Dart method
+      expect(code, contains(r'static void pigeon_setUpMessageHandlers({'));
+      expect(
+        collapsedCode,
+        contains(
+          'final String Function( Api pigeon_instance, Input input, )? doSomethingElse;',
+        ),
+      );
+
+      // Copy method
+      expect(code, contains(r'Api pigeon_copy('));
+    });
+
+    group('inheritance', () {
+      test('extends', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final Root root = Root(apis: <Api>[
+          AstProxyApi(
+            name: 'Api',
+            constructors: <Constructor>[],
+            fields: <ApiField>[],
+            methods: <Method>[],
+            superClass: TypeDeclaration(
+              baseName: 'Api2',
+              isNullable: false,
+              associatedProxyApi: api2,
+            ),
+          ),
+          api2,
+        ], classes: <Class>[], enums: <Enum>[]);
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains(r'class Api extends Api2'));
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.pigeon_detached({ super.pigeon_binaryMessenger, super.pigeon_instanceManager, }) : super.pigeon_detached();',
+          ),
+        );
+      });
+
+      test('implements', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final Root root = Root(apis: <Api>[
+          AstProxyApi(
+            name: 'Api',
+            constructors: <Constructor>[],
+            fields: <ApiField>[],
+            methods: <Method>[],
+            interfaces: <TypeDeclaration>{
+              TypeDeclaration(
+                baseName: 'Api2',
+                isNullable: false,
+                associatedProxyApi: api2,
+              )
+            },
+          ),
+          api2,
+        ], classes: <Class>[], enums: <Enum>[]);
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        expect(
+          code,
+          contains(
+            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2',
+          ),
+        );
+      });
+
+      test('implements 2 ProxyApis', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final AstProxyApi api3 = AstProxyApi(
+          name: 'Api3',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final Root root = Root(apis: <Api>[
+          AstProxyApi(
+            name: 'Api',
+            constructors: <Constructor>[],
+            fields: <ApiField>[],
+            methods: <Method>[],
+            interfaces: <TypeDeclaration>{
+              TypeDeclaration(
+                baseName: 'Api2',
+                isNullable: false,
+                associatedProxyApi: api2,
+              ),
+              TypeDeclaration(
+                baseName: 'Api3',
+                isNullable: false,
+                associatedProxyApi: api2,
+              ),
+            },
+          ),
+          api2,
+          api3,
+        ], classes: <Class>[], enums: <Enum>[]);
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        expect(
+          code,
+          contains(
+            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2, Api3',
+          ),
+        );
+      });
+
+      test('implements inherits flutter methods', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[
+            Method(
+              name: 'aFlutterMethod',
+              returnType: const TypeDeclaration.voidDeclaration(),
+              parameters: <Parameter>[],
+              location: ApiLocation.flutter,
+            ),
+            Method(
+              name: 'aNullableFlutterMethod',
+              returnType: const TypeDeclaration.voidDeclaration(),
+              parameters: <Parameter>[],
+              location: ApiLocation.flutter,
+              isRequired: false,
+            ),
+          ],
+        );
+        final Root root = Root(apis: <Api>[
+          AstProxyApi(
+            name: 'Api',
+            constructors: <Constructor>[],
+            fields: <ApiField>[],
+            methods: <Method>[],
+            interfaces: <TypeDeclaration>{
+              TypeDeclaration(
+                baseName: 'Api2',
+                isNullable: false,
+                associatedProxyApi: api2,
+              )
+            },
+          ),
+          api2,
+        ], classes: <Class>[], enums: <Enum>[]);
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(
+          code,
+          contains(
+            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.pigeon_detached({ super.pigeon_binaryMessenger, '
+            r'super.pigeon_instanceManager, '
+            r'required this.aFlutterMethod, '
+            r'this.aNullableFlutterMethod, })',
+          ),
+        );
+      });
+    });
+
+    group('Constructors', () {
+      test('empty name and no params constructor', () {
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(name: 'Api', constructors: <Constructor>[
+              Constructor(
+                name: '',
+                parameters: <Parameter>[],
+              )
+            ], fields: <ApiField>[], methods: <Method>[]),
+          ],
+          classes: <Class>[],
+          enums: <Enum>[],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'Api({ super.pigeon_binaryMessenger, '
+            r'super.pigeon_instanceManager, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r"const String __pigeon_channelName = 'dev.flutter.pigeon.test_package.Api.pigeon_defaultConstructor';",
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'__pigeon_channel .send(<Object?>[__pigeon_instanceIdentifier])',
+          ),
+        );
+      });
+
+      test('multiple params constructor', () {
+        final Enum anEnum = Enum(
+          name: 'AnEnum',
+          members: <EnumMember>[EnumMember(name: 'one')],
+        );
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(name: 'Api', constructors: <Constructor>[
+              Constructor(
+                name: 'name',
+                parameters: <Parameter>[
+                  Parameter(
+                    type: const TypeDeclaration(
+                      isNullable: false,
+                      baseName: 'int',
+                    ),
+                    name: 'validType',
+                  ),
+                  Parameter(
+                    type: TypeDeclaration(
+                      isNullable: false,
+                      baseName: 'AnEnum',
+                      associatedEnum: anEnum,
+                    ),
+                    name: 'enumType',
+                  ),
+                  Parameter(
+                    type: const TypeDeclaration(
+                      isNullable: false,
+                      baseName: 'Api2',
+                    ),
+                    name: 'proxyApiType',
+                  ),
+                  Parameter(
+                    type: const TypeDeclaration(
+                      isNullable: true,
+                      baseName: 'int',
+                    ),
+                    name: 'nullableValidType',
+                  ),
+                  Parameter(
+                    type: TypeDeclaration(
+                      isNullable: true,
+                      baseName: 'AnEnum',
+                      associatedEnum: anEnum,
+                    ),
+                    name: 'nullableEnumType',
+                  ),
+                  Parameter(
+                    type: const TypeDeclaration(
+                      isNullable: true,
+                      baseName: 'Api2',
+                    ),
+                    name: 'nullableProxyApiType',
+                  ),
+                ],
+              )
+            ], fields: <ApiField>[], methods: <Method>[]),
+            AstProxyApi(
+              name: 'Api2',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[],
+            ),
+          ],
+          classes: <Class>[],
+          enums: <Enum>[anEnum],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.name({ super.pigeon_binaryMessenger, '
+            r'super.pigeon_instanceManager, '
+            r'required int validType, '
+            r'required AnEnum enumType, '
+            r'required Api2 proxyApiType, '
+            r'int? nullableValidType, '
+            r'AnEnum? nullableEnumType, '
+            r'Api2? nullableProxyApiType, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'__pigeon_channel.send(<Object?>[ '
+            r'__pigeon_instanceIdentifier, '
+            r'validType, enumType.index, proxyApiType, '
+            r'nullableValidType, nullableEnumType?.index, nullableProxyApiType ])',
+          ),
+        );
+      });
+    });
+
+    group('Fields', () {
+      test('constructor with fields', () {
+        final Enum anEnum = Enum(
+          name: 'AnEnum',
+          members: <EnumMember>[EnumMember(name: 'one')],
+        );
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[
+                Constructor(
+                  name: 'name',
+                  parameters: <Parameter>[],
+                )
+              ],
+              fields: <ApiField>[
+                ApiField(
+                  type: const TypeDeclaration(
+                    isNullable: false,
+                    baseName: 'int',
+                  ),
+                  name: 'validType',
+                ),
+                ApiField(
+                  type: TypeDeclaration(
+                    isNullable: false,
+                    baseName: 'AnEnum',
+                    associatedEnum: anEnum,
+                  ),
+                  name: 'enumType',
+                ),
+                ApiField(
+                  type: const TypeDeclaration(
+                    isNullable: false,
+                    baseName: 'Api2',
+                  ),
+                  name: 'proxyApiType',
+                ),
+                ApiField(
+                  type: const TypeDeclaration(
+                    isNullable: true,
+                    baseName: 'int',
+                  ),
+                  name: 'nullableValidType',
+                ),
+                ApiField(
+                  type: TypeDeclaration(
+                    isNullable: true,
+                    baseName: 'AnEnum',
+                    associatedEnum: anEnum,
+                  ),
+                  name: 'nullableEnumType',
+                ),
+                ApiField(
+                  type: const TypeDeclaration(
+                    isNullable: true,
+                    baseName: 'Api2',
+                  ),
+                  name: 'nullableProxyApiType',
+                ),
+              ],
+              methods: <Method>[],
+            ),
+            AstProxyApi(
+              name: 'Api2',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[],
+            ),
+          ],
+          classes: <Class>[],
+          enums: <Enum>[anEnum],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'Api.name({ super.pigeon_binaryMessenger, '
+            r'super.pigeon_instanceManager, '
+            r'required this.validType, '
+            r'required this.enumType, '
+            r'required this.proxyApiType, '
+            r'this.nullableValidType, '
+            r'this.nullableEnumType, '
+            r'this.nullableProxyApiType, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'__pigeon_channel.send(<Object?>[ '
+            r'__pigeon_instanceIdentifier, '
+            r'validType, enumType.index, proxyApiType, '
+            r'nullableValidType, nullableEnumType?.index, nullableProxyApiType ])',
+          ),
+        );
+        expect(
+          code,
+          contains(r'final int validType;'),
+        );
+        expect(
+          code,
+          contains(r'final AnEnum enumType;'),
+        );
+        expect(
+          code,
+          contains(r'final Api2 proxyApiType;'),
+        );
+        expect(
+          code,
+          contains(r'final int? nullableValidType;'),
+        );
+        expect(
+          code,
+          contains(r'final AnEnum? nullableEnumType;'),
+        );
+        expect(
+          code,
+          contains(r'final Api2? nullableProxyApiType;'),
+        );
+      });
+
+      test('attached field', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[],
+              fields: <ApiField>[
+                ApiField(
+                  name: 'aField',
+                  isAttached: true,
+                  type: TypeDeclaration(
+                    baseName: 'Api2',
+                    isNullable: false,
+                    associatedProxyApi: api2,
+                  ),
+                ),
+              ],
+              methods: <Method>[],
+            ),
+            api2,
+          ],
+          classes: <Class>[],
+          enums: <Enum>[],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        expect(code, contains('class Api'));
+        expect(code, contains(r'late final Api2 aField = __pigeon_aField();'));
+        expect(code, contains(r'Api2 __pigeon_aField()'));
+      });
+
+      test('static attached field', () {
+        final AstProxyApi api2 = AstProxyApi(
+          name: 'Api2',
+          constructors: <Constructor>[],
+          fields: <ApiField>[],
+          methods: <Method>[],
+        );
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[],
+              fields: <ApiField>[
+                ApiField(
+                  name: 'aField',
+                  isStatic: true,
+                  isAttached: true,
+                  type: TypeDeclaration(
+                    baseName: 'Api2',
+                    isNullable: false,
+                    associatedProxyApi: api2,
+                  ),
+                ),
+              ],
+              methods: <Method>[],
+            ),
+            api2,
+          ],
+          classes: <Class>[],
+          enums: <Enum>[],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        expect(code, contains('class Api'));
+        expect(
+            code, contains(r'static final Api2 aField = __pigeon_aField();'));
+        expect(code, contains(r'static Api2 __pigeon_aField()'));
+      });
+    });
+
+    group('Host methods', () {
+      test('multiple params method', () {
+        final Enum anEnum = Enum(
+          name: 'AnEnum',
+          members: <EnumMember>[EnumMember(name: 'one')],
+        );
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[
+                Method(
+                  name: 'doSomething',
+                  location: ApiLocation.host,
+                  parameters: <Parameter>[
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'int',
+                      ),
+                      name: 'validType',
+                    ),
+                    Parameter(
+                      type: TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'AnEnum',
+                        associatedEnum: anEnum,
+                      ),
+                      name: 'enumType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'Api2',
+                      ),
+                      name: 'proxyApiType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'int',
+                      ),
+                      name: 'nullableValidType',
+                    ),
+                    Parameter(
+                      type: TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'AnEnum',
+                        associatedEnum: anEnum,
+                      ),
+                      name: 'nullableEnumType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'Api2',
+                      ),
+                      name: 'nullableProxyApiType',
+                    ),
+                  ],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                ),
+              ],
+            ),
+            AstProxyApi(
+              name: 'Api2',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[],
+            ),
+          ],
+          classes: <Class>[],
+          enums: <Enum>[anEnum],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'Future<void> doSomething( int validType, AnEnum enumType, '
+            r'Api2 proxyApiType, int? nullableValidType, '
+            r'AnEnum? nullableEnumType, Api2? nullableProxyApiType, )',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'await __pigeon_channel.send(<Object?>[ this, validType, '
+            r'enumType.index, proxyApiType, nullableValidType, '
+            r'nullableEnumType?.index, nullableProxyApiType ])',
+          ),
+        );
+      });
+
+      test('static method', () {
+        final Root root = Root(
+          apis: <Api>[
+            AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[
+                Method(
+                  name: 'doSomething',
+                  location: ApiLocation.host,
+                  isStatic: true,
+                  parameters: <Parameter>[],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                ),
+              ],
+            ),
+          ],
+          classes: <Class>[],
+          enums: <Enum>[],
+        );
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'static Future<void> doSomething({ BinaryMessenger? pigeon_binaryMessenger, '
+            r'Pigeon_InstanceManager? pigeon_instanceManager, })',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(r'await __pigeon_channel.send(null)'),
+        );
+      });
+    });
+
+    group('Flutter methods', () {
+      test('multiple params flutter method', () {
+        final Enum anEnum = Enum(
+          name: 'AnEnum',
+          members: <EnumMember>[EnumMember(name: 'one')],
+        );
+        final Root root = Root(apis: <Api>[
+          AstProxyApi(
+              name: 'Api',
+              constructors: <Constructor>[],
+              fields: <ApiField>[],
+              methods: <Method>[
+                Method(
+                  name: 'doSomething',
+                  location: ApiLocation.flutter,
+                  isRequired: false,
+                  parameters: <Parameter>[
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'int',
+                      ),
+                      name: 'validType',
+                    ),
+                    Parameter(
+                      type: TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'AnEnum',
+                        associatedEnum: anEnum,
+                      ),
+                      name: 'enumType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: false,
+                        baseName: 'Api2',
+                      ),
+                      name: 'proxyApiType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'int',
+                      ),
+                      name: 'nullableValidType',
+                    ),
+                    Parameter(
+                      type: TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'AnEnum',
+                        associatedEnum: anEnum,
+                      ),
+                      name: 'nullableEnumType',
+                    ),
+                    Parameter(
+                      type: const TypeDeclaration(
+                        isNullable: true,
+                        baseName: 'Api2',
+                      ),
+                      name: 'nullableProxyApiType',
+                    ),
+                  ],
+                  returnType: const TypeDeclaration.voidDeclaration(),
+                ),
+              ])
+        ], classes: <Class>[], enums: <Enum>[
+          anEnum
+        ]);
+        final StringBuffer sink = StringBuffer();
+        const DartGenerator generator = DartGenerator();
+        generator.generate(
+          const DartOptions(),
+          root,
+          sink,
+          dartPackageName: DEFAULT_PACKAGE_NAME,
+        );
+        final String code = sink.toString();
+        final String collapsedCode = _collapseNewlineAndIndentation(code);
+        expect(code, contains('class Api'));
+        expect(
+          collapsedCode,
+          contains(
+            r'final void Function( Api pigeon_instance, int validType, '
+            r'AnEnum enumType, Api2 proxyApiType, int? nullableValidType, '
+            r'AnEnum? nullableEnumType, Api2? nullableProxyApiType, )? '
+            r'doSomething;',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+              r'void Function( Api pigeon_instance, int validType, AnEnum enumType, '
+              r'Api2 proxyApiType, int? nullableValidType, '
+              r'AnEnum? nullableEnumType, Api2? nullableProxyApiType, )? '
+              r'doSomething'),
+        );
+        expect(
+          code,
+          contains(r'final Api? arg_pigeon_instance = (args[0] as Api?);'),
+        );
+        expect(
+          code,
+          contains(r'final int? arg_validType = (args[1] as int?);'),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'final AnEnum? arg_enumType = args[2] == null ? '
+            r'null : AnEnum.values[args[2]! as int];',
+          ),
+        );
+        expect(
+          code,
+          contains(r'final Api2? arg_proxyApiType = (args[3] as Api2?);'),
+        );
+        expect(
+          code,
+          contains(r'final int? arg_nullableValidType = (args[4] as int?);'),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'final AnEnum? arg_nullableEnumType = args[5] == null ? '
+            r'null : AnEnum.values[args[5]! as int];',
+          ),
+        );
+        expect(
+          collapsedCode,
+          contains(
+            r'(doSomething ?? arg_pigeon_instance!.doSomething)?.call( arg_pigeon_instance!, '
+            r'arg_validType!, arg_enumType!, arg_proxyApiType!, '
+            r'arg_nullableValidType, arg_nullableEnumType, '
+            r'arg_nullableProxyApiType);',
+          ),
+        );
+      });
+    });
+  });
+}
+
+/// Replaces a new line and the indentation with a single white space
+///
+/// This
+///
+/// ```dart
+/// void method(
+///   int param1,
+///   int param2,
+/// )
+/// ```
+///
+/// converts to
+///
+/// ```dart
+/// void method( int param1, int param2, )
+/// ```
+String _collapseNewlineAndIndentation(String string) {
+  final StringBuffer result = StringBuffer();
+  for (final String line in string.split('\n')) {
+    result.write('${line.trimLeft()} ');
+  }
+  return result.toString().trim();
+}

From b08d0179f7a6008597954f54720eaf253f0a7e43 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 14:30:38 -0500
Subject: [PATCH 23/32] generate test api file

---
 .../example/app/lib/src/messages.g.dart       |    2 +-
 packages/pigeon/lib/dart/templates.dart       |   14 +-
 packages/pigeon/lib/dart_generator.dart       |   48 +-
 packages/pigeon/lib/pigeon.dart               |    4 +-
 packages/pigeon/pigeons/proxy_api_tests.dart  |    3 -
 .../background_platform_channels.gen.dart     |    2 +-
 .../lib/src/generated/core_tests.gen.dart     |    2 +-
 .../lib/src/generated/enum.gen.dart           |    2 +-
 .../src/generated/flutter_unittests.gen.dart  |    2 +-
 .../lib/src/generated/message.gen.dart        |    2 +-
 .../lib/src/generated/multiple_arity.gen.dart |    2 +-
 .../src/generated/non_null_fields.gen.dart    |    2 +-
 .../lib/src/generated/null_fields.gen.dart    |    2 +-
 .../src/generated/nullable_returns.gen.dart   |    2 +-
 .../lib/src/generated/primitive.gen.dart      |    2 +-
 .../src/generated/proxy_api_tests.gen.dart    | 5038 +++++++++++++++++
 .../test/instance_manager_test.dart           |  168 +
 packages/pigeon/tool/shared/generation.dart   |    1 +
 18 files changed, 5254 insertions(+), 44 deletions(-)
 create mode 100644 packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
 create mode 100644 packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart

diff --git a/packages/pigeon/example/app/lib/src/messages.g.dart b/packages/pigeon/example/app/lib/src/messages.g.dart
index 59213e4ef2bb..961e9c5856b5 100644
--- a/packages/pigeon/example/app/lib/src/messages.g.dart
+++ b/packages/pigeon/example/app/lib/src/messages.g.dart
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index 3459fcd5c242..5da28beafc30 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -6,7 +6,6 @@ import '../generator_tools.dart';
 
 /// Creates the `InstanceManager` with the passed string values.
 String instanceManagerTemplate({
-  required String proxyApiBaseClassName,
   required Iterable<String> allProxyApiNames,
 }) {
   final Iterable<String> apiHandlerSetUps = allProxyApiNames.map(
@@ -333,9 +332,9 @@ const String proxyApiBaseClass = '''
 /// All implementers are expected to be [immutable] as defined by the annotation
 /// and override [${classMemberNamePrefix}copy] returning an instance of itself.
 @immutable
-abstract class $_proxyApiBaseClassName {
-  /// Construct a [$_proxyApiBaseClassName].
-  $_proxyApiBaseClassName({
+abstract class $proxyApiBaseClassName {
+  /// Construct a [$proxyApiBaseClassName].
+  $proxyApiBaseClassName({
     this.$_proxyApiBaseClassMessengerVarName,
     $instanceManagerClassName? $_proxyApiBaseClassInstanceManagerVarName,
   }) : $_proxyApiBaseClassInstanceManagerVarName =
@@ -358,7 +357,7 @@ abstract class $_proxyApiBaseClassName {
   /// Subclasses should always override their parent's implementation of this
   /// method.
   @protected
-  $_proxyApiBaseClassName ${classMemberNamePrefix}copy();
+  $proxyApiBaseClassName ${classMemberNamePrefix}copy();
 }
 ''';
 
@@ -373,7 +372,7 @@ class $_proxyApiCodecName extends StandardMessageCodec {
  final $instanceManagerClassName instanceManager;
  @override
  void writeValue(WriteBuffer buffer, Object? value) {
-   if (value is $_proxyApiBaseClassName) {
+   if (value is $proxyApiBaseClassName) {
      buffer.putUint8(128);
      writeValue(buffer, instanceManager.getIdentifier(value));
    } else {
@@ -393,7 +392,8 @@ class $_proxyApiCodecName extends StandardMessageCodec {
 }
 ''';
 
-const String _proxyApiBaseClassName = '${classNamePrefix}ProxyApiBaseClass';
+/// Name of the base class of all ProxyApis.
+const String proxyApiBaseClassName = '${classNamePrefix}ProxyApiBaseClass';
 const String _proxyApiBaseClassMessengerVarName =
     '${classMemberNamePrefix}binaryMessenger';
 const String _proxyApiBaseClassInstanceManagerVarName =
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index d00cfea4c2ee..851649e98525 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -125,7 +125,7 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
 
     final bool hasProxyApi = root.apis.any((Api api) => api is AstProxyApi);
     indent.writeln(
-        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer${hasProxyApi ? ' immutable, protected' : ''};");
+        "import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer${hasProxyApi ? ', immutable, protected' : ''};");
     indent.writeln("import 'package:flutter/services.dart';");
     if (hasProxyApi) {
       indent.writeln(
@@ -463,7 +463,6 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
 
     indent.writeln(
       instanceManagerTemplate(
-        proxyApiBaseClassName: '${classMemberNamePrefix}ProxyApiBaseClass',
         allProxyApiNames: root.apis
             .whereType<AstProxyApi>()
             .map((AstProxyApi api) => api.name),
@@ -551,7 +550,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
         ..name = api.name
         ..extend = api.superClass != null
             ? cb.refer(api.superClass!.baseName)
-            : cb.refer('${classNamePrefix}ProxyApiBaseClass')
+            : cb.refer(proxyApiBaseClassName)
         ..implements.addAll(
           api.interfaces.map(
             (TypeDeclaration type) => cb.refer(type.baseName),
@@ -583,9 +582,9 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           ),
         )
         ..fields.addAll(<cb.Field>[
-          if (api.methods.isNotEmpty ||
-              api.constructors.isNotEmpty ||
-              api.attachedFields.any((ApiField field) => !field.isStatic))
+          if (api.constructors.isNotEmpty ||
+              api.attachedFields.any((ApiField field) => !field.isStatic) ||
+              api.hostMethods.isNotEmpty)
             _proxyApiCodecInstanceField(
               codecInstanceName: codecInstanceName,
               codecName: codecName,
@@ -605,7 +604,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
             dartPackageName: dartPackageName,
             codecName: codecName,
             unattachedFields: api.unattachedFields,
-            hasCallbackConstructor: api.methods
+            hasCallbackConstructor: api.flutterMethods
                 .followedBy(flutterMethodsFromSuperClasses)
                 .followedBy(flutterMethodsFromInterfaces)
                 .every((Method method) => !method.isRequired),
@@ -727,15 +726,22 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     Indent indent, {
     required String dartPackageName,
   }) {
-    final bool hasHostApi =
-        root.apis.any((Api api) => api.methods.isNotEmpty && api is AstHostApi);
-    final bool hasFlutterApi = root.apis
-        .any((Api api) => api.methods.isNotEmpty && api is AstFlutterApi);
-
-    if (hasHostApi) {
+    final bool hasHostMethod = root.apis
+            .whereType<AstHostApi>()
+            .any((AstHostApi api) => api.methods.isNotEmpty) ||
+        root.apis.whereType<AstProxyApi>().any((AstProxyApi api) =>
+            api.constructors.isNotEmpty ||
+            api.attachedFields.isNotEmpty ||
+            api.hostMethods.isNotEmpty);
+    final bool hasFlutterMethod = root.apis
+            .whereType<AstFlutterApi>()
+            .any((AstFlutterApi api) => api.methods.isNotEmpty) ||
+        root.apis.any((Api api) => api is AstProxyApi);
+
+    if (hasHostMethod) {
       _writeCreateConnectionError(indent);
     }
-    if (hasFlutterApi || generatorOptions.testOutPath != null) {
+    if (hasFlutterMethod || generatorOptions.testOutPath != null) {
       _writeWrapResponse(generatorOptions, root, indent);
     }
   }
@@ -1461,12 +1467,14 @@ if (${_varNamePrefix}replyList == null) {
             ),
         ])
         ..body = cb.Block.of(<cb.Code>[
-          cb.Code(
-            'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
-          ),
-          const cb.Code(
-            'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
-          ),
+          if (hasCallbackConstructor || flutterMethods.isNotEmpty) ...<cb.Code>[
+            cb.Code(
+              'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
+            ),
+            const cb.Code(
+              'final BinaryMessenger? binaryMessenger = ${classMemberNamePrefix}binaryMessenger;',
+            )
+          ],
           if (hasCallbackConstructor)
             ...cb.Block((cb.BlockBuilder builder) {
               final StringBuffer messageHandlerSink = StringBuffer();
diff --git a/packages/pigeon/lib/pigeon.dart b/packages/pigeon/lib/pigeon.dart
index a2c6026e3117..7f2fb7505fa8 100644
--- a/packages/pigeon/lib/pigeon.dart
+++ b/packages/pigeon/lib/pigeon.dart
@@ -9,7 +9,5 @@ export 'dart_generator.dart' show DartOptions;
 export 'java_generator.dart' show JavaOptions;
 export 'kotlin_generator.dart' show KotlinOptions;
 export 'objc_generator.dart' show ObjcOptions;
-// TODO(bparrishMines): Remove hide once implementation of the api is finished
-// for Dart and one host language.
-export 'pigeon_lib.dart' hide ProxyApi;
+export 'pigeon_lib.dart';
 export 'swift_generator.dart' show SwiftOptions;
diff --git a/packages/pigeon/pigeons/proxy_api_tests.dart b/packages/pigeon/pigeons/proxy_api_tests.dart
index c09eebd8239d..51c351ab556a 100644
--- a/packages/pigeon/pigeons/proxy_api_tests.dart
+++ b/packages/pigeon/pigeons/proxy_api_tests.dart
@@ -3,9 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:pigeon/pigeon.dart';
-// TODO(bparrishMines): Remove this import when ProxyApi has an implementation
-// for at least one host language.
-import 'package:pigeon/pigeon_lib.dart';
 
 enum AnEnum {
   one,
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
index 7222e263b32b..91dee132ceba 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index 6815f461c943..7ba41cf8e778 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
index 8354d159d33e..f465bf2b765c 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
index 73f100cf28b6..99cbf7fa3711 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
index cc7b8b53c360..04dbc6d43a2a 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
index bec054b4be49..19455117087d 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
index 7279e85c40ea..be9c48422aef 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
index ecf7c7f7e970..bc18ccd0ada0 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
index dd1665a463c1..d5c2bb3f63df 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
index 72c115d65278..b1f618a72b6e 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
new file mode 100644
index 000000000000..68b02de3c24e
--- /dev/null
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -0,0 +1,5038 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Autogenerated from Pigeon, do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+
+import 'dart:async';
+import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
+
+import 'package:flutter/foundation.dart'
+    show ReadBuffer, WriteBuffer, immutable, protected;
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart' show WidgetsFlutterBinding;
+
+PlatformException _createConnectionError(String channelName) {
+  return PlatformException(
+    code: 'channel-error',
+    message: 'Unable to establish connection on channel: "$channelName".',
+  );
+}
+
+List<Object?> wrapResponse(
+    {Object? result, PlatformException? error, bool empty = false}) {
+  if (empty) {
+    return <Object?>[];
+  }
+  if (error == null) {
+    return <Object?>[result];
+  }
+  return <Object?>[error.code, error.message, error.details];
+}
+
+/// An immutable object that serves as the base class for all ProxyApis and
+/// can provide functional copies of itself.
+///
+/// All implementers are expected to be [immutable] as defined by the annotation
+/// and override [pigeon_copy] returning an instance of itself.
+@immutable
+abstract class Pigeon_ProxyApiBaseClass {
+  /// Construct a [Pigeon_ProxyApiBaseClass].
+  Pigeon_ProxyApiBaseClass({
+    this.pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+  }) : pigeon_instanceManager =
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance;
+
+  /// Sends and receives binary data across the Flutter platform barrier.
+  ///
+  /// If it is null, the default BinaryMessenger will be used, which routes to
+  /// the host platform.
+  final BinaryMessenger? pigeon_binaryMessenger;
+
+  /// Maintains instances stored to communicate with native language objects.
+  final Pigeon_InstanceManager pigeon_instanceManager;
+
+  /// Instantiates and returns a functionally identical object to oneself.
+  ///
+  /// Outside of tests, this method should only ever be called by
+  /// [Pigeon_InstanceManager].
+  ///
+  /// Subclasses should always override their parent's implementation of this
+  /// method.
+  @protected
+  Pigeon_ProxyApiBaseClass pigeon_copy();
+}
+
+/// Maintains instances used to communicate with the native objects they
+/// represent.
+///
+/// Added instances are stored as weak references and their copies are stored
+/// as strong references to maintain access to their variables and callback
+/// methods. Both are stored with the same identifier.
+///
+/// When a weak referenced instance becomes inaccessible,
+/// [onWeakReferenceRemoved] is called with its associated identifier.
+///
+/// If an instance is retrieved and has the possibility to be used,
+/// (e.g. calling [getInstanceWithWeakReference]) a copy of the strong reference
+/// is added as a weak reference with the same identifier. This prevents a
+/// scenario where the weak referenced instance was released and then later
+/// returned by the host platform.
+class Pigeon_InstanceManager {
+  /// Constructs a [Pigeon_InstanceManager].
+  Pigeon_InstanceManager({required void Function(int) onWeakReferenceRemoved}) {
+    this.onWeakReferenceRemoved = (int identifier) {
+      _weakInstances.remove(identifier);
+      onWeakReferenceRemoved(identifier);
+    };
+    _finalizer = Finalizer<int>(this.onWeakReferenceRemoved);
+  }
+
+  // Identifiers are locked to a specific range to avoid collisions with objects
+  // created simultaneously by the host platform.
+  // Host uses identifiers >= 2^16 and Dart is expected to use values n where,
+  // 0 <= n < 2^16.
+  static const int _maxDartCreatedIdentifier = 65536;
+
+  /// The default [Pigeon_InstanceManager] used by ProxyApis.
+  ///
+  /// On creation, this manager makes a call to clear the native
+  /// InstanceManager. This is to prevent identifier conflicts after a host
+  /// restart.
+  static final Pigeon_InstanceManager instance = _initInstance();
+
+  // Expando is used because it doesn't prevent its keys from becoming
+  // inaccessible. This allows the manager to efficiently retrieve an identifier
+  // of an instance without holding a strong reference to that instance.
+  //
+  // It also doesn't use `==` to search for identifiers, which would lead to an
+  // infinite loop when comparing an object to its copy. (i.e. which was caused
+  // by calling instanceManager.getIdentifier() inside of `==` while this was a
+  // HashMap).
+  final Expando<int> _identifiers = Expando<int>();
+  final Map<int, WeakReference<Pigeon_ProxyApiBaseClass>> _weakInstances =
+      <int, WeakReference<Pigeon_ProxyApiBaseClass>>{};
+  final Map<int, Pigeon_ProxyApiBaseClass> _strongInstances =
+      <int, Pigeon_ProxyApiBaseClass>{};
+  late final Finalizer<int> _finalizer;
+  int _nextIdentifier = 0;
+
+  /// Called when a weak referenced instance is removed by [removeWeakReference]
+  /// or becomes inaccessible.
+  late final void Function(int) onWeakReferenceRemoved;
+
+  static Pigeon_InstanceManager _initInstance() {
+    WidgetsFlutterBinding.ensureInitialized();
+    final _Pigeon_InstanceManagerApi api = _Pigeon_InstanceManagerApi();
+    // Clears the native `Pigeon_InstanceManager` on the initial use of the Dart one.
+    api.clear();
+    final Pigeon_InstanceManager instanceManager = Pigeon_InstanceManager(
+      onWeakReferenceRemoved: (int identifier) {
+        api.removeStrongReference(identifier);
+      },
+    );
+    _Pigeon_InstanceManagerApi.setUpMessageHandlers(
+        instanceManager: instanceManager);
+    ProxyApiTestClass.pigeon_setUpMessageHandlers(
+        pigeon_instanceManager: instanceManager);
+    ProxyApiSuperClass.pigeon_setUpMessageHandlers(
+        pigeon_instanceManager: instanceManager);
+    ProxyApiInterface.pigeon_setUpMessageHandlers(
+        pigeon_instanceManager: instanceManager);
+    return instanceManager;
+  }
+
+  /// Adds a new instance that was instantiated by Dart.
+  ///
+  /// In other words, Dart wants to add a new instance that will represent
+  /// an object that will be instantiated on the host platform.
+  ///
+  /// Throws assertion error if the instance has already been added.
+  ///
+  /// Returns the randomly generated id of the [instance] added.
+  int addDartCreatedInstance(Pigeon_ProxyApiBaseClass instance) {
+    final int identifier = _nextUniqueIdentifier();
+    _addInstanceWithIdentifier(instance, identifier);
+    return identifier;
+  }
+
+  /// Removes the instance, if present, and call [onWeakReferenceRemoved] with
+  /// its identifier.
+  ///
+  /// Returns the identifier associated with the removed instance. Otherwise,
+  /// `null` if the instance was not found in this manager.
+  ///
+  /// This does not remove the strong referenced instance associated with
+  /// [instance]. This can be done with [remove].
+  int? removeWeakReference(Pigeon_ProxyApiBaseClass instance) {
+    final int? identifier = getIdentifier(instance);
+    if (identifier == null) {
+      return null;
+    }
+
+    _identifiers[instance] = null;
+    _finalizer.detach(instance);
+    onWeakReferenceRemoved(identifier);
+
+    return identifier;
+  }
+
+  /// Removes [identifier] and its associated strongly referenced instance, if
+  /// present, from the manager.
+  ///
+  /// Returns the strong referenced instance associated with [identifier] before
+  /// it was removed. Returns `null` if [identifier] was not associated with
+  /// any strong reference.
+  ///
+  /// This does not remove the weak referenced instance associated with
+  /// [identifier]. This can be done with [removeWeakReference].
+  T? remove<T extends Pigeon_ProxyApiBaseClass>(int identifier) {
+    return _strongInstances.remove(identifier) as T?;
+  }
+
+  /// Retrieves the instance associated with identifier.
+  ///
+  /// The value returned is chosen from the following order:
+  ///
+  /// 1. A weakly referenced instance associated with identifier.
+  /// 2. If the only instance associated with identifier is a strongly
+  /// referenced instance, a copy of the instance is added as a weak reference
+  /// with the same identifier. Returning the newly created copy.
+  /// 3. If no instance is associated with identifier, returns null.
+  ///
+  /// This method also expects the host `InstanceManager` to have a strong
+  /// reference to the instance the identifier is associated with.
+  T? getInstanceWithWeakReference<T extends Pigeon_ProxyApiBaseClass>(
+      int identifier) {
+    final Pigeon_ProxyApiBaseClass? weakInstance =
+        _weakInstances[identifier]?.target;
+
+    if (weakInstance == null) {
+      final Pigeon_ProxyApiBaseClass? strongInstance =
+          _strongInstances[identifier];
+      if (strongInstance != null) {
+        final Pigeon_ProxyApiBaseClass copy = strongInstance.pigeon_copy();
+        _identifiers[copy] = identifier;
+        _weakInstances[identifier] =
+            WeakReference<Pigeon_ProxyApiBaseClass>(copy);
+        _finalizer.attach(copy, identifier, detach: copy);
+        return copy as T;
+      }
+      return strongInstance as T?;
+    }
+
+    return weakInstance as T;
+  }
+
+  /// Retrieves the identifier associated with instance.
+  int? getIdentifier(Pigeon_ProxyApiBaseClass instance) {
+    return _identifiers[instance];
+  }
+
+  /// Adds a new instance that was instantiated by the host platform.
+  ///
+  /// In other words, the host platform wants to add a new instance that
+  /// represents an object on the host platform. Stored with [identifier].
+  ///
+  /// Throws assertion error if the instance or its identifier has already been
+  /// added.
+  ///
+  /// Returns unique identifier of the [instance] added.
+  void addHostCreatedInstance(
+      Pigeon_ProxyApiBaseClass instance, int identifier) {
+    _addInstanceWithIdentifier(instance, identifier);
+  }
+
+  void _addInstanceWithIdentifier(
+      Pigeon_ProxyApiBaseClass instance, int identifier) {
+    assert(!containsIdentifier(identifier));
+    assert(getIdentifier(instance) == null);
+    assert(identifier >= 0);
+
+    _identifiers[instance] = identifier;
+    _weakInstances[identifier] =
+        WeakReference<Pigeon_ProxyApiBaseClass>(instance);
+    _finalizer.attach(instance, identifier, detach: instance);
+
+    final Pigeon_ProxyApiBaseClass copy = instance.pigeon_copy();
+    _identifiers[copy] = identifier;
+    _strongInstances[identifier] = copy;
+  }
+
+  /// Whether this manager contains the given [identifier].
+  bool containsIdentifier(int identifier) {
+    return _weakInstances.containsKey(identifier) ||
+        _strongInstances.containsKey(identifier);
+  }
+
+  int _nextUniqueIdentifier() {
+    late int identifier;
+    do {
+      identifier = _nextIdentifier;
+      _nextIdentifier = (_nextIdentifier + 1) % _maxDartCreatedIdentifier;
+    } while (containsIdentifier(identifier));
+    return identifier;
+  }
+}
+
+/// Generated API for managing the Dart and native `Pigeon_InstanceManager`s.
+class _Pigeon_InstanceManagerApi {
+  /// Constructor for [_Pigeon_InstanceManagerApi ].
+  _Pigeon_InstanceManagerApi({BinaryMessenger? binaryMessenger})
+      : _binaryMessenger = binaryMessenger;
+
+  final BinaryMessenger? _binaryMessenger;
+
+  static const MessageCodec<Object?> pigeonChannelCodec =
+      StandardMessageCodec();
+
+  static void setUpMessageHandlers({
+    BinaryMessenger? binaryMessenger,
+    Pigeon_InstanceManager? instanceManager,
+  }) {
+    const String channelName =
+        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.removeStrongReference';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      pigeonChannelCodec,
+      binaryMessenger: binaryMessenger,
+    );
+    channel.setMessageHandler((Object? message) async {
+      assert(
+        message != null,
+        'Argument for $channelName was null.',
+      );
+      final int? identifier = message as int?;
+      assert(
+        identifier != null,
+        r'Argument for $channelName, expected non-null int.',
+      );
+      (instanceManager ?? Pigeon_InstanceManager.instance).remove(identifier!);
+      return;
+    });
+  }
+
+  Future<void> removeStrongReference(int identifier) async {
+    const String channelName =
+        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.removeStrongReference';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      pigeonChannelCodec,
+      binaryMessenger: _binaryMessenger,
+    );
+    final List<Object?>? replyList =
+        await channel.send(identifier) as List<Object?>?;
+    if (replyList == null) {
+      throw _createConnectionError(channelName);
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Clear the native `Pigeon_InstanceManager`.
+  ///
+  /// This is typically called after a hot restart.
+  Future<void> clear() async {
+    const String channelName =
+        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.clear';
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+      channelName,
+      pigeonChannelCodec,
+      binaryMessenger: _binaryMessenger,
+    );
+    final List<Object?>? replyList = await channel.send(null) as List<Object?>?;
+    if (replyList == null) {
+      throw _createConnectionError(channelName);
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+}
+
+class _Pigeon_ProxyApiBaseCodec extends StandardMessageCodec {
+  const _Pigeon_ProxyApiBaseCodec(this.instanceManager);
+  final Pigeon_InstanceManager instanceManager;
+  @override
+  void writeValue(WriteBuffer buffer, Object? value) {
+    if (value is Pigeon_ProxyApiBaseClass) {
+      buffer.putUint8(128);
+      writeValue(buffer, instanceManager.getIdentifier(value));
+    } else {
+      super.writeValue(buffer, value);
+    }
+  }
+
+  @override
+  Object? readValueOfType(int type, ReadBuffer buffer) {
+    switch (type) {
+      case 128:
+        return instanceManager
+            .getInstanceWithWeakReference(readValue(buffer)! as int);
+      default:
+        return super.readValueOfType(type, buffer);
+    }
+  }
+}
+
+enum AnEnum {
+  one,
+  two,
+  three,
+}
+
+/// The core interface that each host language plugin must implement in
+/// platform_test integration tests.
+class ProxyApiTestClass extends ProxyApiSuperClass
+    implements ProxyApiInterface {
+  ProxyApiTestClass({
+    super.pigeon_binaryMessenger,
+    super.pigeon_instanceManager,
+    required this.aBool,
+    required this.anInt,
+    required this.aDouble,
+    required this.aString,
+    required this.aUint8List,
+    required this.aList,
+    required this.aMap,
+    required this.anEnum,
+    required this.aProxyApi,
+    this.aNullableBool,
+    this.aNullableInt,
+    this.aNullableDouble,
+    this.aNullableString,
+    this.aNullableUint8List,
+    this.aNullableList,
+    this.aNullableMap,
+    this.aNullableEnum,
+    this.aNullableProxyApi,
+    this.anInterfaceMethod,
+    this.flutterNoop,
+    this.flutterThrowError,
+    this.flutterThrowErrorFromVoid,
+    this.flutterEchoBool,
+    this.flutterEchoInt,
+    this.flutterEchoDouble,
+    this.flutterEchoString,
+    this.flutterEchoUint8List,
+    this.flutterEchoList,
+    this.flutterEchoProxyApiList,
+    this.flutterEchoMap,
+    this.flutterEchoProxyApiMap,
+    this.flutterEchoEnum,
+    this.flutterEchoProxyApi,
+    this.flutterEchoNullableBool,
+    this.flutterEchoNullableInt,
+    this.flutterEchoNullableDouble,
+    this.flutterEchoNullableString,
+    this.flutterEchoNullableUint8List,
+    this.flutterEchoNullableList,
+    this.flutterEchoNullableMap,
+    this.flutterEchoNullableEnum,
+    this.flutterEchoNullableProxyApi,
+    this.flutterNoopAsync,
+    this.flutterEchoAsyncString,
+    required bool boolParam,
+    required int intParam,
+    required double doubleParam,
+    required String stringParam,
+    required Uint8List aUint8ListParam,
+    required List<Object?> listParam,
+    required Map<String?, Object?> mapParam,
+    required AnEnum enumParam,
+    required ProxyApiSuperClass proxyApiParam,
+    bool? nullableBoolParam,
+    int? nullableIntParam,
+    double? nullableDoubleParam,
+    String? nullableStringParam,
+    Uint8List? nullableUint8ListParam,
+    List<Object?>? nullableListParam,
+    Map<String?, Object?>? nullableMapParam,
+    AnEnum? nullableEnumParam,
+    ProxyApiSuperClass? nullableProxyApiParam,
+  }) : super.pigeon_detached() {
+    final int __pigeon_instanceIdentifier =
+        pigeon_instanceManager.addDartCreatedInstance(this);
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    () async {
+      const String __pigeon_channelName =
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_defaultConstructor';
+      final BasicMessageChannel<Object?> __pigeon_channel =
+          BasicMessageChannel<Object?>(
+        __pigeon_channelName,
+        pigeonChannelCodec,
+        binaryMessenger: __pigeon_binaryMessenger,
+      );
+      final List<Object?>? __pigeon_replyList =
+          await __pigeon_channel.send(<Object?>[
+        __pigeon_instanceIdentifier,
+        aBool,
+        anInt,
+        aDouble,
+        aString,
+        aUint8List,
+        aList,
+        aMap,
+        anEnum.index,
+        aProxyApi,
+        aNullableBool,
+        aNullableInt,
+        aNullableDouble,
+        aNullableString,
+        aNullableUint8List,
+        aNullableList,
+        aNullableMap,
+        aNullableEnum?.index,
+        aNullableProxyApi,
+        boolParam,
+        intParam,
+        doubleParam,
+        stringParam,
+        aUint8ListParam,
+        listParam,
+        mapParam,
+        enumParam.index,
+        proxyApiParam,
+        nullableBoolParam,
+        nullableIntParam,
+        nullableDoubleParam,
+        nullableStringParam,
+        nullableUint8ListParam,
+        nullableListParam,
+        nullableMapParam,
+        nullableEnumParam?.index,
+        nullableProxyApiParam
+      ]) as List<Object?>?;
+      if (__pigeon_replyList == null) {
+        throw _createConnectionError(__pigeon_channelName);
+      } else if (__pigeon_replyList.length > 1) {
+        throw PlatformException(
+          code: __pigeon_replyList[0]! as String,
+          message: __pigeon_replyList[1] as String?,
+          details: __pigeon_replyList[2],
+        );
+      } else {
+        return;
+      }
+    }();
+  }
+
+  /// Constructs ProxyApiTestClass without creating the associated native object.
+  ///
+  /// This should only be used by subclasses created by this library or to
+  /// create copies for an [Pigeon_InstanceManager].
+  ProxyApiTestClass.pigeon_detached({
+    super.pigeon_binaryMessenger,
+    super.pigeon_instanceManager,
+    required this.aBool,
+    required this.anInt,
+    required this.aDouble,
+    required this.aString,
+    required this.aUint8List,
+    required this.aList,
+    required this.aMap,
+    required this.anEnum,
+    required this.aProxyApi,
+    this.aNullableBool,
+    this.aNullableInt,
+    this.aNullableDouble,
+    this.aNullableString,
+    this.aNullableUint8List,
+    this.aNullableList,
+    this.aNullableMap,
+    this.aNullableEnum,
+    this.aNullableProxyApi,
+    this.anInterfaceMethod,
+    this.flutterNoop,
+    this.flutterThrowError,
+    this.flutterThrowErrorFromVoid,
+    this.flutterEchoBool,
+    this.flutterEchoInt,
+    this.flutterEchoDouble,
+    this.flutterEchoString,
+    this.flutterEchoUint8List,
+    this.flutterEchoList,
+    this.flutterEchoProxyApiList,
+    this.flutterEchoMap,
+    this.flutterEchoProxyApiMap,
+    this.flutterEchoEnum,
+    this.flutterEchoProxyApi,
+    this.flutterEchoNullableBool,
+    this.flutterEchoNullableInt,
+    this.flutterEchoNullableDouble,
+    this.flutterEchoNullableString,
+    this.flutterEchoNullableUint8List,
+    this.flutterEchoNullableList,
+    this.flutterEchoNullableMap,
+    this.flutterEchoNullableEnum,
+    this.flutterEchoNullableProxyApi,
+    this.flutterNoopAsync,
+    this.flutterEchoAsyncString,
+  }) : super.pigeon_detached();
+
+  late final _Pigeon_ProxyApiBaseCodec __pigeon_codecProxyApiTestClass =
+      _Pigeon_ProxyApiBaseCodec(pigeon_instanceManager);
+
+  final bool aBool;
+
+  final int anInt;
+
+  final double aDouble;
+
+  final String aString;
+
+  final Uint8List aUint8List;
+
+  final List<Object?> aList;
+
+  final Map<String?, Object?> aMap;
+
+  final AnEnum anEnum;
+
+  final ProxyApiSuperClass aProxyApi;
+
+  final bool? aNullableBool;
+
+  final int? aNullableInt;
+
+  final double? aNullableDouble;
+
+  final String? aNullableString;
+
+  final Uint8List? aNullableUint8List;
+
+  final List<Object?>? aNullableList;
+
+  final Map<String?, Object?>? aNullableMap;
+
+  final AnEnum? aNullableEnum;
+
+  final ProxyApiSuperClass? aNullableProxyApi;
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic calling.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterNoop: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final void Function(ProxyApiTestClass pigeon_instance)? flutterNoop;
+
+  /// Responds with an error from an async function returning a value.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterThrowError: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError;
+
+  /// Responds with an error from an async void function.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterThrowErrorFromVoid: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final void Function(ProxyApiTestClass pigeon_instance)?
+      flutterThrowErrorFromVoid;
+
+  /// Returns the passed boolean, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoBool: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final bool Function(
+    ProxyApiTestClass pigeon_instance,
+    bool aBool,
+  )? flutterEchoBool;
+
+  /// Returns the passed int, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoInt: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final int Function(
+    ProxyApiTestClass pigeon_instance,
+    int anInt,
+  )? flutterEchoInt;
+
+  /// Returns the passed double, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoDouble: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final double Function(
+    ProxyApiTestClass pigeon_instance,
+    double aDouble,
+  )? flutterEchoDouble;
+
+  /// Returns the passed string, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoString: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final String Function(
+    ProxyApiTestClass pigeon_instance,
+    String aString,
+  )? flutterEchoString;
+
+  /// Returns the passed byte list, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoUint8List: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Uint8List Function(
+    ProxyApiTestClass pigeon_instance,
+    Uint8List aList,
+  )? flutterEchoUint8List;
+
+  /// Returns the passed list, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoList: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final List<Object?> Function(
+    ProxyApiTestClass pigeon_instance,
+    List<Object?> aList,
+  )? flutterEchoList;
+
+  /// Returns the passed list with ProxyApis, to test serialization and
+  /// deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoProxyApiList: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final List<ProxyApiTestClass?> Function(
+    ProxyApiTestClass pigeon_instance,
+    List<ProxyApiTestClass?> aList,
+  )? flutterEchoProxyApiList;
+
+  /// Returns the passed map, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoMap: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Map<String?, Object?> Function(
+    ProxyApiTestClass pigeon_instance,
+    Map<String?, Object?> aMap,
+  )? flutterEchoMap;
+
+  /// Returns the passed map with ProxyApis, to test serialization and
+  /// deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoProxyApiMap: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Map<String?, ProxyApiTestClass?> Function(
+    ProxyApiTestClass pigeon_instance,
+    Map<String?, ProxyApiTestClass?> aMap,
+  )? flutterEchoProxyApiMap;
+
+  /// Returns the passed enum to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoEnum: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final AnEnum Function(
+    ProxyApiTestClass pigeon_instance,
+    AnEnum anEnum,
+  )? flutterEchoEnum;
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoProxyApi: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final ProxyApiSuperClass Function(
+    ProxyApiTestClass pigeon_instance,
+    ProxyApiSuperClass aProxyApi,
+  )? flutterEchoProxyApi;
+
+  /// Returns the passed boolean, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableBool: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final bool? Function(
+    ProxyApiTestClass pigeon_instance,
+    bool? aBool,
+  )? flutterEchoNullableBool;
+
+  /// Returns the passed int, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableInt: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final int? Function(
+    ProxyApiTestClass pigeon_instance,
+    int? anInt,
+  )? flutterEchoNullableInt;
+
+  /// Returns the passed double, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableDouble: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final double? Function(
+    ProxyApiTestClass pigeon_instance,
+    double? aDouble,
+  )? flutterEchoNullableDouble;
+
+  /// Returns the passed string, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableString: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final String? Function(
+    ProxyApiTestClass pigeon_instance,
+    String? aString,
+  )? flutterEchoNullableString;
+
+  /// Returns the passed byte list, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableUint8List: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Uint8List? Function(
+    ProxyApiTestClass pigeon_instance,
+    Uint8List? aList,
+  )? flutterEchoNullableUint8List;
+
+  /// Returns the passed list, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableList: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final List<Object?>? Function(
+    ProxyApiTestClass pigeon_instance,
+    List<Object?>? aList,
+  )? flutterEchoNullableList;
+
+  /// Returns the passed map, to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableMap: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Map<String?, Object?>? Function(
+    ProxyApiTestClass pigeon_instance,
+    Map<String?, Object?>? aMap,
+  )? flutterEchoNullableMap;
+
+  /// Returns the passed enum to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableEnum: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final AnEnum? Function(
+    ProxyApiTestClass pigeon_instance,
+    AnEnum? anEnum,
+  )? flutterEchoNullableEnum;
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoNullableProxyApi: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final ProxyApiSuperClass? Function(
+    ProxyApiTestClass pigeon_instance,
+    ProxyApiSuperClass? aProxyApi,
+  )? flutterEchoNullableProxyApi;
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic asynchronous calling.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterNoopAsync: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Future<void> Function(ProxyApiTestClass pigeon_instance)?
+      flutterNoopAsync;
+
+  /// Returns the passed in generic Object asynchronously.
+  ///
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiTestClass instance = ProxyApiTestClass(
+  ///  flutterEchoAsyncString: (ProxyApiTestClass pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final Future<String> Function(
+    ProxyApiTestClass pigeon_instance,
+    String aString,
+  )? flutterEchoAsyncString;
+
+  @override
+  final void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod;
+
+  late final ProxyApiSuperClass attachedField = __pigeon_attachedField();
+
+  static final ProxyApiSuperClass staticAttachedField =
+      __pigeon_staticAttachedField();
+
+  static void pigeon_setUpMessageHandlers({
+    bool pigeon_clearHandlers = false,
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+    ProxyApiTestClass Function(
+      bool aBool,
+      int anInt,
+      double aDouble,
+      String aString,
+      Uint8List aUint8List,
+      List<Object?> aList,
+      Map<String?, Object?> aMap,
+      AnEnum anEnum,
+      ProxyApiSuperClass aProxyApi,
+      bool? aNullableBool,
+      int? aNullableInt,
+      double? aNullableDouble,
+      String? aNullableString,
+      Uint8List? aNullableUint8List,
+      List<Object?>? aNullableList,
+      Map<String?, Object?>? aNullableMap,
+      AnEnum? aNullableEnum,
+      ProxyApiSuperClass? aNullableProxyApi,
+    )? pigeon_newInstance,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
+    Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError,
+    void Function(ProxyApiTestClass pigeon_instance)? flutterThrowErrorFromVoid,
+    bool Function(
+      ProxyApiTestClass pigeon_instance,
+      bool aBool,
+    )? flutterEchoBool,
+    int Function(
+      ProxyApiTestClass pigeon_instance,
+      int anInt,
+    )? flutterEchoInt,
+    double Function(
+      ProxyApiTestClass pigeon_instance,
+      double aDouble,
+    )? flutterEchoDouble,
+    String Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    )? flutterEchoString,
+    Uint8List Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List aList,
+    )? flutterEchoUint8List,
+    List<Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?> aList,
+    )? flutterEchoList,
+    List<ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      List<ProxyApiTestClass?> aList,
+    )? flutterEchoProxyApiList,
+    Map<String?, Object?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?> aMap,
+    )? flutterEchoMap,
+    Map<String?, ProxyApiTestClass?> Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, ProxyApiTestClass?> aMap,
+    )? flutterEchoProxyApiMap,
+    AnEnum Function(
+      ProxyApiTestClass pigeon_instance,
+      AnEnum anEnum,
+    )? flutterEchoEnum,
+    ProxyApiSuperClass Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass aProxyApi,
+    )? flutterEchoProxyApi,
+    bool? Function(
+      ProxyApiTestClass pigeon_instance,
+      bool? aBool,
+    )? flutterEchoNullableBool,
+    int? Function(
+      ProxyApiTestClass pigeon_instance,
+      int? anInt,
+    )? flutterEchoNullableInt,
+    double? Function(
+      ProxyApiTestClass pigeon_instance,
+      double? aDouble,
+    )? flutterEchoNullableDouble,
+    String? Function(
+      ProxyApiTestClass pigeon_instance,
+      String? aString,
+    )? flutterEchoNullableString,
+    Uint8List? Function(
+      ProxyApiTestClass pigeon_instance,
+      Uint8List? aList,
+    )? flutterEchoNullableUint8List,
+    List<Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      List<Object?>? aList,
+    )? flutterEchoNullableList,
+    Map<String?, Object?>? Function(
+      ProxyApiTestClass pigeon_instance,
+      Map<String?, Object?>? aMap,
+    )? flutterEchoNullableMap,
+    AnEnum? Function(
+      ProxyApiTestClass pigeon_instance,
+      AnEnum? anEnum,
+    )? flutterEchoNullableEnum,
+    ProxyApiSuperClass? Function(
+      ProxyApiTestClass pigeon_instance,
+      ProxyApiSuperClass? aProxyApi,
+    )? flutterEchoNullableProxyApi,
+    Future<void> Function(ProxyApiTestClass pigeon_instance)? flutterNoopAsync,
+    Future<String> Function(
+      ProxyApiTestClass pigeon_instance,
+      String aString,
+    )? flutterEchoAsyncString,
+  }) {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final int? arg_pigeon_instanceIdentifier = (args[0] as int?);
+          assert(arg_pigeon_instanceIdentifier != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null int.');
+          final bool? arg_aBool = (args[1] as bool?);
+          assert(arg_aBool != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null bool.');
+          final int? arg_anInt = (args[2] as int?);
+          assert(arg_anInt != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null int.');
+          final double? arg_aDouble = (args[3] as double?);
+          assert(arg_aDouble != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null double.');
+          final String? arg_aString = (args[4] as String?);
+          assert(arg_aString != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null String.');
+          final Uint8List? arg_aUint8List = (args[5] as Uint8List?);
+          assert(arg_aUint8List != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null Uint8List.');
+          final List<Object?>? arg_aList =
+              (args[6] as List<Object?>?)?.cast<Object?>();
+          assert(arg_aList != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null List<Object?>.');
+          final Map<String?, Object?>? arg_aMap =
+              (args[7] as Map<Object?, Object?>?)?.cast<String?, Object?>();
+          assert(arg_aMap != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null Map<String?, Object?>.');
+          final AnEnum? arg_anEnum =
+              args[8] == null ? null : AnEnum.values[args[8]! as int];
+          assert(arg_anEnum != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null AnEnum.');
+          final ProxyApiSuperClass? arg_aProxyApi =
+              (args[9] as ProxyApiSuperClass?);
+          assert(arg_aProxyApi != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null ProxyApiSuperClass.');
+          final bool? arg_aNullableBool = (args[10] as bool?);
+          final int? arg_aNullableInt = (args[11] as int?);
+          final double? arg_aNullableDouble = (args[12] as double?);
+          final String? arg_aNullableString = (args[13] as String?);
+          final Uint8List? arg_aNullableUint8List = (args[14] as Uint8List?);
+          final List<Object?>? arg_aNullableList =
+              (args[15] as List<Object?>?)?.cast<Object?>();
+          final Map<String?, Object?>? arg_aNullableMap =
+              (args[16] as Map<Object?, Object?>?)?.cast<String?, Object?>();
+          final AnEnum? arg_aNullableEnum =
+              args[17] == null ? null : AnEnum.values[args[17]! as int];
+          final ProxyApiSuperClass? arg_aNullableProxyApi =
+              (args[18] as ProxyApiSuperClass?);
+          try {
+            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+                .addHostCreatedInstance(
+              pigeon_newInstance?.call(
+                      arg_aBool!,
+                      arg_anInt!,
+                      arg_aDouble!,
+                      arg_aString!,
+                      arg_aUint8List!,
+                      arg_aList!,
+                      arg_aMap!,
+                      arg_anEnum!,
+                      arg_aProxyApi!,
+                      arg_aNullableBool,
+                      arg_aNullableInt,
+                      arg_aNullableDouble,
+                      arg_aNullableString,
+                      arg_aNullableUint8List,
+                      arg_aNullableList,
+                      arg_aNullableMap,
+                      arg_aNullableEnum,
+                      arg_aNullableProxyApi) ??
+                  ProxyApiTestClass.pigeon_detached(
+                    pigeon_binaryMessenger: pigeon_binaryMessenger,
+                    pigeon_instanceManager: pigeon_instanceManager,
+                    aBool: arg_aBool!,
+                    anInt: arg_anInt!,
+                    aDouble: arg_aDouble!,
+                    aString: arg_aString!,
+                    aUint8List: arg_aUint8List!,
+                    aList: arg_aList!,
+                    aMap: arg_aMap!,
+                    anEnum: arg_anEnum!,
+                    aProxyApi: arg_aProxyApi!,
+                    aNullableBool: arg_aNullableBool,
+                    aNullableInt: arg_aNullableInt,
+                    aNullableDouble: arg_aNullableDouble,
+                    aNullableString: arg_aNullableString,
+                    aNullableUint8List: arg_aNullableUint8List,
+                    aNullableList: arg_aNullableList,
+                    aNullableMap: arg_aNullableMap,
+                    aNullableEnum: arg_aNullableEnum,
+                    aNullableProxyApi: arg_aNullableProxyApi,
+                  ),
+              arg_pigeon_instanceIdentifier!,
+            );
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoop',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoop was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoop was null, expected non-null ProxyApiTestClass.');
+          try {
+            (flutterNoop ?? arg_pigeon_instance!.flutterNoop)
+                ?.call(arg_pigeon_instance!);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowError',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowError was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowError was null, expected non-null ProxyApiTestClass.');
+          try {
+            final Object? output =
+                (flutterThrowError ?? arg_pigeon_instance!.flutterThrowError)
+                    ?.call(arg_pigeon_instance!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowErrorFromVoid',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowErrorFromVoid was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterThrowErrorFromVoid was null, expected non-null ProxyApiTestClass.');
+          try {
+            (flutterThrowErrorFromVoid ??
+                    arg_pigeon_instance!.flutterThrowErrorFromVoid)
+                ?.call(arg_pigeon_instance!);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoBool',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoBool was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoBool was null, expected non-null ProxyApiTestClass.');
+          final bool? arg_aBool = (args[1] as bool?);
+          assert(arg_aBool != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoBool was null, expected non-null bool.');
+          try {
+            final bool? output =
+                (flutterEchoBool ?? arg_pigeon_instance!.flutterEchoBool)
+                    ?.call(arg_pigeon_instance!, arg_aBool!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoInt',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoInt was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoInt was null, expected non-null ProxyApiTestClass.');
+          final int? arg_anInt = (args[1] as int?);
+          assert(arg_anInt != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoInt was null, expected non-null int.');
+          try {
+            final int? output =
+                (flutterEchoInt ?? arg_pigeon_instance!.flutterEchoInt)
+                    ?.call(arg_pigeon_instance!, arg_anInt!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoDouble',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoDouble was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoDouble was null, expected non-null ProxyApiTestClass.');
+          final double? arg_aDouble = (args[1] as double?);
+          assert(arg_aDouble != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoDouble was null, expected non-null double.');
+          try {
+            final double? output =
+                (flutterEchoDouble ?? arg_pigeon_instance!.flutterEchoDouble)
+                    ?.call(arg_pigeon_instance!, arg_aDouble!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoString',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoString was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoString was null, expected non-null ProxyApiTestClass.');
+          final String? arg_aString = (args[1] as String?);
+          assert(arg_aString != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoString was null, expected non-null String.');
+          try {
+            final String? output =
+                (flutterEchoString ?? arg_pigeon_instance!.flutterEchoString)
+                    ?.call(arg_pigeon_instance!, arg_aString!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoUint8List',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoUint8List was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoUint8List was null, expected non-null ProxyApiTestClass.');
+          final Uint8List? arg_aList = (args[1] as Uint8List?);
+          assert(arg_aList != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoUint8List was null, expected non-null Uint8List.');
+          try {
+            final Uint8List? output = (flutterEchoUint8List ??
+                    arg_pigeon_instance!.flutterEchoUint8List)
+                ?.call(arg_pigeon_instance!, arg_aList!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoList',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoList was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoList was null, expected non-null ProxyApiTestClass.');
+          final List<Object?>? arg_aList =
+              (args[1] as List<Object?>?)?.cast<Object?>();
+          assert(arg_aList != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoList was null, expected non-null List<Object?>.');
+          try {
+            final List<Object?>? output =
+                (flutterEchoList ?? arg_pigeon_instance!.flutterEchoList)
+                    ?.call(arg_pigeon_instance!, arg_aList!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiList',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiList was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiList was null, expected non-null ProxyApiTestClass.');
+          final List<ProxyApiTestClass?>? arg_aList =
+              (args[1] as List<Object?>?)?.cast<ProxyApiTestClass?>();
+          assert(arg_aList != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiList was null, expected non-null List<ProxyApiTestClass?>.');
+          try {
+            final List<ProxyApiTestClass?>? output = (flutterEchoProxyApiList ??
+                    arg_pigeon_instance!.flutterEchoProxyApiList)
+                ?.call(arg_pigeon_instance!, arg_aList!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoMap',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoMap was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoMap was null, expected non-null ProxyApiTestClass.');
+          final Map<String?, Object?>? arg_aMap =
+              (args[1] as Map<Object?, Object?>?)?.cast<String?, Object?>();
+          assert(arg_aMap != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoMap was null, expected non-null Map<String?, Object?>.');
+          try {
+            final Map<String?, Object?>? output =
+                (flutterEchoMap ?? arg_pigeon_instance!.flutterEchoMap)
+                    ?.call(arg_pigeon_instance!, arg_aMap!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiMap',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiMap was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiMap was null, expected non-null ProxyApiTestClass.');
+          final Map<String?, ProxyApiTestClass?>? arg_aMap =
+              (args[1] as Map<Object?, Object?>?)
+                  ?.cast<String?, ProxyApiTestClass?>();
+          assert(arg_aMap != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApiMap was null, expected non-null Map<String?, ProxyApiTestClass?>.');
+          try {
+            final Map<String?, ProxyApiTestClass?>? output =
+                (flutterEchoProxyApiMap ??
+                        arg_pigeon_instance!.flutterEchoProxyApiMap)
+                    ?.call(arg_pigeon_instance!, arg_aMap!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null, expected non-null ProxyApiTestClass.');
+          final AnEnum? arg_anEnum =
+              args[1] == null ? null : AnEnum.values[args[1]! as int];
+          assert(arg_anEnum != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null, expected non-null AnEnum.');
+          try {
+            final AnEnum? output =
+                (flutterEchoEnum ?? arg_pigeon_instance!.flutterEchoEnum)
+                    ?.call(arg_pigeon_instance!, arg_anEnum!);
+            return wrapResponse(result: output?.index);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApi',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApi was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApi was null, expected non-null ProxyApiTestClass.');
+          final ProxyApiSuperClass? arg_aProxyApi =
+              (args[1] as ProxyApiSuperClass?);
+          assert(arg_aProxyApi != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoProxyApi was null, expected non-null ProxyApiSuperClass.');
+          try {
+            final ProxyApiSuperClass? output = (flutterEchoProxyApi ??
+                    arg_pigeon_instance!.flutterEchoProxyApi)
+                ?.call(arg_pigeon_instance!, arg_aProxyApi!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableBool',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableBool was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableBool was null, expected non-null ProxyApiTestClass.');
+          final bool? arg_aBool = (args[1] as bool?);
+          try {
+            final bool? output = (flutterEchoNullableBool ??
+                    arg_pigeon_instance!.flutterEchoNullableBool)
+                ?.call(arg_pigeon_instance!, arg_aBool);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableInt',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableInt was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableInt was null, expected non-null ProxyApiTestClass.');
+          final int? arg_anInt = (args[1] as int?);
+          try {
+            final int? output = (flutterEchoNullableInt ??
+                    arg_pigeon_instance!.flutterEchoNullableInt)
+                ?.call(arg_pigeon_instance!, arg_anInt);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableDouble',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableDouble was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableDouble was null, expected non-null ProxyApiTestClass.');
+          final double? arg_aDouble = (args[1] as double?);
+          try {
+            final double? output = (flutterEchoNullableDouble ??
+                    arg_pigeon_instance!.flutterEchoNullableDouble)
+                ?.call(arg_pigeon_instance!, arg_aDouble);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableString',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableString was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableString was null, expected non-null ProxyApiTestClass.');
+          final String? arg_aString = (args[1] as String?);
+          try {
+            final String? output = (flutterEchoNullableString ??
+                    arg_pigeon_instance!.flutterEchoNullableString)
+                ?.call(arg_pigeon_instance!, arg_aString);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableUint8List',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableUint8List was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableUint8List was null, expected non-null ProxyApiTestClass.');
+          final Uint8List? arg_aList = (args[1] as Uint8List?);
+          try {
+            final Uint8List? output = (flutterEchoNullableUint8List ??
+                    arg_pigeon_instance!.flutterEchoNullableUint8List)
+                ?.call(arg_pigeon_instance!, arg_aList);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableList',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableList was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableList was null, expected non-null ProxyApiTestClass.');
+          final List<Object?>? arg_aList =
+              (args[1] as List<Object?>?)?.cast<Object?>();
+          try {
+            final List<Object?>? output = (flutterEchoNullableList ??
+                    arg_pigeon_instance!.flutterEchoNullableList)
+                ?.call(arg_pigeon_instance!, arg_aList);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableMap',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableMap was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableMap was null, expected non-null ProxyApiTestClass.');
+          final Map<String?, Object?>? arg_aMap =
+              (args[1] as Map<Object?, Object?>?)?.cast<String?, Object?>();
+          try {
+            final Map<String?, Object?>? output = (flutterEchoNullableMap ??
+                    arg_pigeon_instance!.flutterEchoNullableMap)
+                ?.call(arg_pigeon_instance!, arg_aMap);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableEnum',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableEnum was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableEnum was null, expected non-null ProxyApiTestClass.');
+          final AnEnum? arg_anEnum =
+              args[1] == null ? null : AnEnum.values[args[1]! as int];
+          try {
+            final AnEnum? output = (flutterEchoNullableEnum ??
+                    arg_pigeon_instance!.flutterEchoNullableEnum)
+                ?.call(arg_pigeon_instance!, arg_anEnum);
+            return wrapResponse(result: output?.index);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableProxyApi',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableProxyApi was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableProxyApi was null, expected non-null ProxyApiTestClass.');
+          final ProxyApiSuperClass? arg_aProxyApi =
+              (args[1] as ProxyApiSuperClass?);
+          try {
+            final ProxyApiSuperClass? output = (flutterEchoNullableProxyApi ??
+                    arg_pigeon_instance!.flutterEchoNullableProxyApi)
+                ?.call(arg_pigeon_instance!, arg_aProxyApi);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoopAsync',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoopAsync was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterNoopAsync was null, expected non-null ProxyApiTestClass.');
+          try {
+            await (flutterNoopAsync ?? arg_pigeon_instance!.flutterNoopAsync)
+                ?.call(arg_pigeon_instance!);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoAsyncString',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoAsyncString was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiTestClass? arg_pigeon_instance =
+              (args[0] as ProxyApiTestClass?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoAsyncString was null, expected non-null ProxyApiTestClass.');
+          final String? arg_aString = (args[1] as String?);
+          assert(arg_aString != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoAsyncString was null, expected non-null String.');
+          try {
+            final String? output = await (flutterEchoAsyncString ??
+                    arg_pigeon_instance!.flutterEchoAsyncString)
+                ?.call(arg_pigeon_instance!, arg_aString!);
+            return wrapResponse(result: output);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+  }
+
+  ProxyApiSuperClass __pigeon_attachedField() {
+    final ProxyApiSuperClass __pigeon_instance =
+        ProxyApiSuperClass.pigeon_detached(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+    );
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    final int __pigeon_instanceIdentifier =
+        pigeon_instanceManager.addDartCreatedInstance(__pigeon_instance);
+    () async {
+      const String __pigeon_channelName =
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.attachedField';
+      final BasicMessageChannel<Object?> __pigeon_channel =
+          BasicMessageChannel<Object?>(
+        __pigeon_channelName,
+        pigeonChannelCodec,
+        binaryMessenger: __pigeon_binaryMessenger,
+      );
+      final List<Object?>? __pigeon_replyList = await __pigeon_channel
+          .send(<Object?>[this, __pigeon_instanceIdentifier]) as List<Object?>?;
+      if (__pigeon_replyList == null) {
+        throw _createConnectionError(__pigeon_channelName);
+      } else if (__pigeon_replyList.length > 1) {
+        throw PlatformException(
+          code: __pigeon_replyList[0]! as String,
+          message: __pigeon_replyList[1] as String?,
+          details: __pigeon_replyList[2],
+        );
+      } else {
+        return;
+      }
+    }();
+    return __pigeon_instance;
+  }
+
+  static ProxyApiSuperClass __pigeon_staticAttachedField() {
+    final ProxyApiSuperClass __pigeon_instance =
+        ProxyApiSuperClass.pigeon_detached();
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(Pigeon_InstanceManager.instance);
+    final BinaryMessenger __pigeon_binaryMessenger =
+        ServicesBinding.instance.defaultBinaryMessenger;
+    final int __pigeon_instanceIdentifier = Pigeon_InstanceManager.instance
+        .addDartCreatedInstance(__pigeon_instance);
+    () async {
+      const String __pigeon_channelName =
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.staticAttachedField';
+      final BasicMessageChannel<Object?> __pigeon_channel =
+          BasicMessageChannel<Object?>(
+        __pigeon_channelName,
+        pigeonChannelCodec,
+        binaryMessenger: __pigeon_binaryMessenger,
+      );
+      final List<Object?>? __pigeon_replyList = await __pigeon_channel
+          .send(<Object?>[__pigeon_instanceIdentifier]) as List<Object?>?;
+      if (__pigeon_replyList == null) {
+        throw _createConnectionError(__pigeon_channelName);
+      } else if (__pigeon_replyList.length > 1) {
+        throw PlatformException(
+          code: __pigeon_replyList[0]! as String,
+          message: __pigeon_replyList[1] as String?,
+          details: __pigeon_replyList[2],
+        );
+      } else {
+        return;
+      }
+    }();
+    return __pigeon_instance;
+  }
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic calling.
+  Future<void> noop() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.noop';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Returns an error, to test error handling.
+  Future<Object?> throwError() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwError';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Returns an error from a void function, to test error handling.
+  Future<void> throwErrorFromVoid() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwErrorFromVoid';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Returns a Flutter error, to test error handling.
+  Future<Object?> throwFlutterError() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwFlutterError';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Returns passed in int.
+  Future<int> echoInt(int anInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, anInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?)!;
+    }
+  }
+
+  /// Returns passed in double.
+  Future<double> echoDouble(double aDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?)!;
+    }
+  }
+
+  /// Returns the passed in boolean.
+  Future<bool> echoBool(bool aBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?)!;
+    }
+  }
+
+  /// Returns the passed in string.
+  Future<String> echoString(String aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?)!;
+    }
+  }
+
+  /// Returns the passed in Uint8List.
+  Future<Uint8List> echoUint8List(Uint8List aUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?)!;
+    }
+  }
+
+  /// Returns the passed in generic Object.
+  Future<Object> echoObject(Object anObject) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoObject';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anObject]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return __pigeon_replyList[0]!;
+    }
+  }
+
+  /// Returns the passed list, to test serialization and deserialization.
+  Future<List<Object?>> echoList(List<Object?> aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)!.cast<Object?>();
+    }
+  }
+
+  /// Returns the passed list with ProxyApis, to test serialization and
+  /// deserialization.
+  Future<List<ProxyApiTestClass?>> echoProxyApiList(
+      List<ProxyApiTestClass?> aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoProxyApiList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)!
+          .cast<ProxyApiTestClass?>();
+    }
+  }
+
+  /// Returns the passed map, to test serialization and deserialization.
+  Future<Map<String?, Object?>> echoMap(Map<String?, Object?> aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)!
+          .cast<String?, Object?>();
+    }
+  }
+
+  /// Returns the passed map with ProxyApis, to test serialization and
+  /// deserialization.
+  Future<Map<String?, ProxyApiTestClass?>> echoProxyApiMap(
+      Map<String?, ProxyApiTestClass?> aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoProxyApiMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)!
+          .cast<String?, ProxyApiTestClass?>();
+    }
+  }
+
+  /// Returns the passed enum to test serialization and deserialization.
+  Future<AnEnum> echoEnum(AnEnum anEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anEnum.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  Future<ProxyApiSuperClass> echoProxyApi(ProxyApiSuperClass aProxyApi) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoProxyApi';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aProxyApi]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as ProxyApiSuperClass?)!;
+    }
+  }
+
+  /// Returns passed in int.
+  Future<int?> echoNullableInt(int? aNullableInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?);
+    }
+  }
+
+  /// Returns passed in double.
+  Future<double?> echoNullableDouble(double? aNullableDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?);
+    }
+  }
+
+  /// Returns the passed in boolean.
+  Future<bool?> echoNullableBool(bool? aNullableBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?);
+    }
+  }
+
+  /// Returns the passed in string.
+  Future<String?> echoNullableString(String? aNullableString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?);
+    }
+  }
+
+  /// Returns the passed in Uint8List.
+  Future<Uint8List?> echoNullableUint8List(
+      Uint8List? aNullableUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?);
+    }
+  }
+
+  /// Returns the passed in generic Object.
+  Future<Object?> echoNullableObject(Object? aNullableObject) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableObject';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableObject]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Returns the passed list, to test serialization and deserialization.
+  Future<List<Object?>?> echoNullableList(List<Object?>? aNullableList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)?.cast<Object?>();
+    }
+  }
+
+  /// Returns the passed map, to test serialization and deserialization.
+  Future<Map<String?, Object?>?> echoNullableMap(
+      Map<String?, Object?>? aNullableMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)
+          ?.cast<String?, Object?>();
+    }
+  }
+
+  Future<AnEnum?> echoNullableEnum(AnEnum? aNullableEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableEnum?.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?) == null
+          ? null
+          : AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  /// Returns the passed ProxyApi to test serialization and deserialization.
+  Future<ProxyApiSuperClass?> echoNullableProxyApi(
+      ProxyApiSuperClass? aNullableProxyApi) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoNullableProxyApi';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aNullableProxyApi]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as ProxyApiSuperClass?);
+    }
+  }
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic asynchronous calling.
+  Future<void> noopAsync() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.noopAsync';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Returns passed in int asynchronously.
+  Future<int> echoAsyncInt(int anInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, anInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?)!;
+    }
+  }
+
+  /// Returns passed in double asynchronously.
+  Future<double> echoAsyncDouble(double aDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?)!;
+    }
+  }
+
+  /// Returns the passed in boolean asynchronously.
+  Future<bool> echoAsyncBool(bool aBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?)!;
+    }
+  }
+
+  /// Returns the passed string asynchronously.
+  Future<String> echoAsyncString(String aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?)!;
+    }
+  }
+
+  /// Returns the passed in Uint8List asynchronously.
+  Future<Uint8List> echoAsyncUint8List(Uint8List aUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?)!;
+    }
+  }
+
+  /// Returns the passed in generic Object asynchronously.
+  Future<Object> echoAsyncObject(Object anObject) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncObject';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anObject]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return __pigeon_replyList[0]!;
+    }
+  }
+
+  /// Returns the passed list, to test asynchronous serialization and deserialization.
+  Future<List<Object?>> echoAsyncList(List<Object?> aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)!.cast<Object?>();
+    }
+  }
+
+  /// Returns the passed map, to test asynchronous serialization and deserialization.
+  Future<Map<String?, Object?>> echoAsyncMap(Map<String?, Object?> aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)!
+          .cast<String?, Object?>();
+    }
+  }
+
+  /// Returns the passed enum, to test asynchronous serialization and deserialization.
+  Future<AnEnum> echoAsyncEnum(AnEnum anEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anEnum.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  /// Responds with an error from an async function returning a value.
+  Future<Object?> throwAsyncError() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwAsyncError';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Responds with an error from an async void function.
+  Future<void> throwAsyncErrorFromVoid() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwAsyncErrorFromVoid';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Responds with a Flutter error from an async function returning a value.
+  Future<Object?> throwAsyncFlutterError() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.throwAsyncFlutterError';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Returns passed in int asynchronously.
+  Future<int?> echoAsyncNullableInt(int? anInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, anInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?);
+    }
+  }
+
+  /// Returns passed in double asynchronously.
+  Future<double?> echoAsyncNullableDouble(double? aDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?);
+    }
+  }
+
+  /// Returns the passed in boolean asynchronously.
+  Future<bool?> echoAsyncNullableBool(bool? aBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?);
+    }
+  }
+
+  /// Returns the passed string asynchronously.
+  Future<String?> echoAsyncNullableString(String? aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?);
+    }
+  }
+
+  /// Returns the passed in Uint8List asynchronously.
+  Future<Uint8List?> echoAsyncNullableUint8List(Uint8List? aUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?);
+    }
+  }
+
+  /// Returns the passed in generic Object asynchronously.
+  Future<Object?> echoAsyncNullableObject(Object? anObject) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableObject';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anObject]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  /// Returns the passed list, to test asynchronous serialization and deserialization.
+  Future<List<Object?>?> echoAsyncNullableList(List<Object?>? aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)?.cast<Object?>();
+    }
+  }
+
+  /// Returns the passed map, to test asynchronous serialization and deserialization.
+  Future<Map<String?, Object?>?> echoAsyncNullableMap(
+      Map<String?, Object?>? aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)
+          ?.cast<String?, Object?>();
+    }
+  }
+
+  /// Returns the passed enum, to test asynchronous serialization and deserialization.
+  Future<AnEnum?> echoAsyncNullableEnum(AnEnum? anEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoAsyncNullableEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anEnum?.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?) == null
+          ? null
+          : AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  static Future<void> staticNoop({
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+  }) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.staticNoop';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  static Future<String> echoStaticString(
+    String aString, {
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+  }) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoStaticString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?)!;
+    }
+  }
+
+  static Future<void> staticAsyncNoop({
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+  }) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.staticAsyncNoop';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> callFlutterNoop() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterNoop';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<Object?> callFlutterThrowError() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterThrowError';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return __pigeon_replyList[0];
+    }
+  }
+
+  Future<void> callFlutterThrowErrorFromVoid() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterThrowErrorFromVoid';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<bool> callFlutterEchoBool(bool aBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?)!;
+    }
+  }
+
+  Future<int> callFlutterEchoInt(int anInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, anInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?)!;
+    }
+  }
+
+  Future<double> callFlutterEchoDouble(double aDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?)!;
+    }
+  }
+
+  Future<String> callFlutterEchoString(String aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?)!;
+    }
+  }
+
+  Future<Uint8List> callFlutterEchoUint8List(Uint8List aUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?)!;
+    }
+  }
+
+  Future<List<Object?>> callFlutterEchoList(List<Object?> aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)!.cast<Object?>();
+    }
+  }
+
+  Future<List<ProxyApiTestClass?>> callFlutterEchoProxyApiList(
+      List<ProxyApiTestClass?> aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoProxyApiList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)!
+          .cast<ProxyApiTestClass?>();
+    }
+  }
+
+  Future<Map<String?, Object?>> callFlutterEchoMap(
+      Map<String?, Object?> aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)!
+          .cast<String?, Object?>();
+    }
+  }
+
+  Future<Map<String?, ProxyApiTestClass?>> callFlutterEchoProxyApiMap(
+      Map<String?, ProxyApiTestClass?> aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoProxyApiMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)!
+          .cast<String?, ProxyApiTestClass?>();
+    }
+  }
+
+  Future<AnEnum> callFlutterEchoEnum(AnEnum anEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anEnum.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  Future<ProxyApiSuperClass> callFlutterEchoProxyApi(
+      ProxyApiSuperClass aProxyApi) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoProxyApi';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aProxyApi]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as ProxyApiSuperClass?)!;
+    }
+  }
+
+  Future<bool?> callFlutterEchoNullableBool(bool? aBool) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableBool';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aBool]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as bool?);
+    }
+  }
+
+  Future<int?> callFlutterEchoNullableInt(int? anInt) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableInt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, anInt]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?);
+    }
+  }
+
+  Future<double?> callFlutterEchoNullableDouble(double? aDouble) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableDouble';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aDouble]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as double?);
+    }
+  }
+
+  Future<String?> callFlutterEchoNullableString(String? aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?);
+    }
+  }
+
+  Future<Uint8List?> callFlutterEchoNullableUint8List(
+      Uint8List? aUint8List) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableUint8List';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aUint8List]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Uint8List?);
+    }
+  }
+
+  Future<List<Object?>?> callFlutterEchoNullableList(
+      List<Object?>? aList) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableList';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aList]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as List<Object?>?)?.cast<Object?>();
+    }
+  }
+
+  Future<Map<String?, Object?>?> callFlutterEchoNullableMap(
+      Map<String?, Object?>? aMap) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableMap';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aMap]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as Map<Object?, Object?>?)
+          ?.cast<String?, Object?>();
+    }
+  }
+
+  Future<AnEnum?> callFlutterEchoNullableEnum(AnEnum? anEnum) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableEnum';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, anEnum?.index]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as int?) == null
+          ? null
+          : AnEnum.values[__pigeon_replyList[0]! as int];
+    }
+  }
+
+  Future<ProxyApiSuperClass?> callFlutterEchoNullableProxyApi(
+      ProxyApiSuperClass? aProxyApi) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoNullableProxyApi';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[this, aProxyApi]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as ProxyApiSuperClass?);
+    }
+  }
+
+  Future<void> callFlutterNoopAsync() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterNoopAsync';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<String> callFlutterEchoAsyncString(String aString) async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiTestClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.callFlutterEchoAsyncString';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this, aString]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else if (__pigeon_replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?)!;
+    }
+  }
+
+  @override
+  ProxyApiTestClass pigeon_copy() {
+    return ProxyApiTestClass.pigeon_detached(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+      aBool: aBool,
+      anInt: anInt,
+      aDouble: aDouble,
+      aString: aString,
+      aUint8List: aUint8List,
+      aList: aList,
+      aMap: aMap,
+      anEnum: anEnum,
+      aProxyApi: aProxyApi,
+      aNullableBool: aNullableBool,
+      aNullableInt: aNullableInt,
+      aNullableDouble: aNullableDouble,
+      aNullableString: aNullableString,
+      aNullableUint8List: aNullableUint8List,
+      aNullableList: aNullableList,
+      aNullableMap: aNullableMap,
+      aNullableEnum: aNullableEnum,
+      aNullableProxyApi: aNullableProxyApi,
+      anInterfaceMethod: anInterfaceMethod,
+      flutterNoop: flutterNoop,
+      flutterThrowError: flutterThrowError,
+      flutterThrowErrorFromVoid: flutterThrowErrorFromVoid,
+      flutterEchoBool: flutterEchoBool,
+      flutterEchoInt: flutterEchoInt,
+      flutterEchoDouble: flutterEchoDouble,
+      flutterEchoString: flutterEchoString,
+      flutterEchoUint8List: flutterEchoUint8List,
+      flutterEchoList: flutterEchoList,
+      flutterEchoProxyApiList: flutterEchoProxyApiList,
+      flutterEchoMap: flutterEchoMap,
+      flutterEchoProxyApiMap: flutterEchoProxyApiMap,
+      flutterEchoEnum: flutterEchoEnum,
+      flutterEchoProxyApi: flutterEchoProxyApi,
+      flutterEchoNullableBool: flutterEchoNullableBool,
+      flutterEchoNullableInt: flutterEchoNullableInt,
+      flutterEchoNullableDouble: flutterEchoNullableDouble,
+      flutterEchoNullableString: flutterEchoNullableString,
+      flutterEchoNullableUint8List: flutterEchoNullableUint8List,
+      flutterEchoNullableList: flutterEchoNullableList,
+      flutterEchoNullableMap: flutterEchoNullableMap,
+      flutterEchoNullableEnum: flutterEchoNullableEnum,
+      flutterEchoNullableProxyApi: flutterEchoNullableProxyApi,
+      flutterNoopAsync: flutterNoopAsync,
+      flutterEchoAsyncString: flutterEchoAsyncString,
+    );
+  }
+}
+
+/// ProxyApi to serve as a super class to the core ProxyApi interface.
+class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
+  ProxyApiSuperClass({
+    super.pigeon_binaryMessenger,
+    super.pigeon_instanceManager,
+  }) {
+    final int __pigeon_instanceIdentifier =
+        pigeon_instanceManager.addDartCreatedInstance(this);
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiSuperClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    () async {
+      const String __pigeon_channelName =
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.pigeon_defaultConstructor';
+      final BasicMessageChannel<Object?> __pigeon_channel =
+          BasicMessageChannel<Object?>(
+        __pigeon_channelName,
+        pigeonChannelCodec,
+        binaryMessenger: __pigeon_binaryMessenger,
+      );
+      final List<Object?>? __pigeon_replyList = await __pigeon_channel
+          .send(<Object?>[__pigeon_instanceIdentifier]) as List<Object?>?;
+      if (__pigeon_replyList == null) {
+        throw _createConnectionError(__pigeon_channelName);
+      } else if (__pigeon_replyList.length > 1) {
+        throw PlatformException(
+          code: __pigeon_replyList[0]! as String,
+          message: __pigeon_replyList[1] as String?,
+          details: __pigeon_replyList[2],
+        );
+      } else {
+        return;
+      }
+    }();
+  }
+
+  /// Constructs ProxyApiSuperClass without creating the associated native object.
+  ///
+  /// This should only be used by subclasses created by this library or to
+  /// create copies for an [Pigeon_InstanceManager].
+  ProxyApiSuperClass.pigeon_detached({
+    super.pigeon_binaryMessenger,
+    super.pigeon_instanceManager,
+  });
+
+  late final _Pigeon_ProxyApiBaseCodec __pigeon_codecProxyApiSuperClass =
+      _Pigeon_ProxyApiBaseCodec(pigeon_instanceManager);
+
+  static void pigeon_setUpMessageHandlers({
+    bool pigeon_clearHandlers = false,
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+    ProxyApiSuperClass Function()? pigeon_newInstance,
+  }) {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.pigeon_newInstance',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.pigeon_newInstance was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final int? arg_pigeon_instanceIdentifier = (args[0] as int?);
+          assert(arg_pigeon_instanceIdentifier != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.pigeon_newInstance was null, expected non-null int.');
+          try {
+            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+                .addHostCreatedInstance(
+              pigeon_newInstance?.call() ??
+                  ProxyApiSuperClass.pigeon_detached(
+                    pigeon_binaryMessenger: pigeon_binaryMessenger,
+                    pigeon_instanceManager: pigeon_instanceManager,
+                  ),
+              arg_pigeon_instanceIdentifier!,
+            );
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+  }
+
+  Future<void> aSuperMethod() async {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        __pigeon_codecProxyApiSuperClass;
+    final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.aSuperMethod';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(<Object?>[this]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  @override
+  ProxyApiSuperClass pigeon_copy() {
+    return ProxyApiSuperClass.pigeon_detached(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+    );
+  }
+}
+
+/// ProxyApi to serve as an interface to the core ProxyApi interface.
+class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
+  /// Constructs ProxyApiInterface without creating the associated native object.
+  ///
+  /// This should only be used by subclasses created by this library or to
+  /// create copies for an [Pigeon_InstanceManager].
+  ProxyApiInterface.pigeon_detached({
+    super.pigeon_binaryMessenger,
+    super.pigeon_instanceManager,
+    this.anInterfaceMethod,
+  });
+
+  /// Dart:
+  /// For the associated Native object to be automatically garbage collected,
+  /// it is required that the implementation of this `Function` doesn't have a
+  /// strong reference to the encapsulating class instance. When this `Function`
+  /// references a non-local variable, it is strongly recommended to access it
+  /// from a `WeakReference`:
+  ///
+  /// ```dart
+  /// final WeakReference weakMyVariable = WeakReference(myVariable);
+  /// final ProxyApiInterface instance = ProxyApiInterface(
+  ///  anInterfaceMethod: (ProxyApiInterface pigeon_instance, ...) {
+  ///    print(weakMyVariable?.target);
+  ///  },
+  /// );
+  /// ```
+  ///
+  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// release the associated Native object manually.
+  final void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod;
+
+  static void pigeon_setUpMessageHandlers({
+    bool pigeon_clearHandlers = false,
+    BinaryMessenger? pigeon_binaryMessenger,
+    Pigeon_InstanceManager? pigeon_instanceManager,
+    ProxyApiInterface Function()? pigeon_newInstance,
+    void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
+  }) {
+    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+        _Pigeon_ProxyApiBaseCodec(
+            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.pigeon_newInstance',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.pigeon_newInstance was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final int? arg_pigeon_instanceIdentifier = (args[0] as int?);
+          assert(arg_pigeon_instanceIdentifier != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.pigeon_newInstance was null, expected non-null int.');
+          try {
+            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+                .addHostCreatedInstance(
+              pigeon_newInstance?.call() ??
+                  ProxyApiInterface.pigeon_detached(
+                    pigeon_binaryMessenger: pigeon_binaryMessenger,
+                    pigeon_instanceManager: pigeon_instanceManager,
+                  ),
+              arg_pigeon_instanceIdentifier!,
+            );
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.anInterfaceMethod',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (pigeon_clearHandlers) {
+        __pigeon_channel.setMessageHandler(null);
+      } else {
+        __pigeon_channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.anInterfaceMethod was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final ProxyApiInterface? arg_pigeon_instance =
+              (args[0] as ProxyApiInterface?);
+          assert(arg_pigeon_instance != null,
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.anInterfaceMethod was null, expected non-null ProxyApiInterface.');
+          try {
+            (anInterfaceMethod ?? arg_pigeon_instance!.anInterfaceMethod)
+                ?.call(arg_pigeon_instance!);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+  }
+
+  @override
+  ProxyApiInterface pigeon_copy() {
+    return ProxyApiInterface.pigeon_detached(
+      pigeon_binaryMessenger: pigeon_binaryMessenger,
+      pigeon_instanceManager: pigeon_instanceManager,
+      anInterfaceMethod: anInterfaceMethod,
+    );
+  }
+}
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart
new file mode 100644
index 000000000000..fc5ceba03dfb
--- /dev/null
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart
@@ -0,0 +1,168 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file specifically tests the test Pigeon_InstanceManager generated by core_tests.
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:shared_test_plugin_code/src/generated/proxy_api_tests.gen.dart';
+
+void main() {
+  group('InstanceManager', () {
+    test('addHostCreatedInstance', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+
+      expect(instanceManager.getIdentifier(object), 0);
+      expect(
+        instanceManager.getInstanceWithWeakReference(0),
+        object,
+      );
+    });
+
+    test('addHostCreatedInstance prevents already used objects and ids', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+
+      expect(
+        () => instanceManager.addHostCreatedInstance(object, 0),
+        throwsAssertionError,
+      );
+
+      expect(
+        () => instanceManager.addHostCreatedInstance(
+          CopyableObject(pigeon_instanceManager: instanceManager),
+          0,
+        ),
+        throwsAssertionError,
+      );
+    });
+
+    test('addFlutterCreatedInstance', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addDartCreatedInstance(object);
+
+      final int? instanceId = instanceManager.getIdentifier(object);
+      expect(instanceId, isNotNull);
+      expect(
+        instanceManager.getInstanceWithWeakReference(instanceId!),
+        object,
+      );
+    });
+
+    test('removeWeakReference', () {
+      int? weakInstanceId;
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (int instanceId) {
+        weakInstanceId = instanceId;
+      });
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+
+      expect(instanceManager.removeWeakReference(object), 0);
+      expect(
+        instanceManager.getInstanceWithWeakReference(0),
+        isA<CopyableObject>(),
+      );
+      expect(weakInstanceId, 0);
+    });
+
+    test('removeWeakReference removes only weak reference', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+
+      expect(instanceManager.removeWeakReference(object), 0);
+      final CopyableObject copy = instanceManager.getInstanceWithWeakReference(
+        0,
+      )!;
+      expect(identical(object, copy), isFalse);
+    });
+
+    test('removeStrongReference', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+      instanceManager.removeWeakReference(object);
+      expect(instanceManager.remove(0), isA<CopyableObject>());
+      expect(instanceManager.containsIdentifier(0), isFalse);
+    });
+
+    test('removeStrongReference removes only strong reference', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+      expect(instanceManager.remove(0), isA<CopyableObject>());
+      expect(
+        instanceManager.getInstanceWithWeakReference(0),
+        object,
+      );
+    });
+
+    test('getInstance can add a new weak reference', () {
+      final Pigeon_InstanceManager instanceManager =
+          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+
+      final CopyableObject object = CopyableObject(
+        pigeon_instanceManager: instanceManager,
+      );
+
+      instanceManager.addHostCreatedInstance(object, 0);
+      instanceManager.removeWeakReference(object);
+
+      final CopyableObject newWeakCopy =
+          instanceManager.getInstanceWithWeakReference(
+        0,
+      )!;
+      expect(identical(object, newWeakCopy), isFalse);
+    });
+  });
+}
+
+class CopyableObject extends Pigeon_ProxyApiBaseClass {
+  // ignore: non_constant_identifier_names
+  CopyableObject({super.pigeon_instanceManager});
+
+  @override
+  // ignore: non_constant_identifier_names
+  CopyableObject pigeon_copy() {
+    return CopyableObject(pigeon_instanceManager: pigeon_instanceManager);
+  }
+}
diff --git a/packages/pigeon/tool/shared/generation.dart b/packages/pigeon/tool/shared/generation.dart
index 9915e26aa57d..c14e923b85dc 100644
--- a/packages/pigeon/tool/shared/generation.dart
+++ b/packages/pigeon/tool/shared/generation.dart
@@ -68,6 +68,7 @@ Future<int> generateTestPigeons({required String baseDir}) async {
     'null_fields',
     'nullable_returns',
     'primitive',
+    'proxy_api_tests',
   ];
 
   final String outputBase = p.join(baseDir, 'platform_tests', 'test_plugin');

From fc3df6f14c748ab3c7c706a3aec10b3ce43b1b97 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 14:58:51 -0500
Subject: [PATCH 24/32] method improvements

---
 packages/pigeon/lib/dart_generator.dart | 29 ++++++++++---------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 851649e98525..4cb24e0ab61b 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -516,11 +516,12 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
 
     // All ProxyApis this API `implements` and all the interfaces those APIs
     // `implements`.
-    final Set<AstProxyApi> interfacesApis = recursiveFindAllInterfaceApis(api);
+    final Set<AstProxyApi> apisOfInterfaces =
+        recursiveFindAllInterfaceApis(api);
 
     // All methods inherited from interfaces and the interfaces of interfaces.
     final List<Method> flutterMethodsFromInterfaces = <Method>[];
-    for (final AstProxyApi proxyApi in interfacesApis) {
+    for (final AstProxyApi proxyApi in apisOfInterfaces) {
       flutterMethodsFromInterfaces.addAll(proxyApi.methods);
     }
 
@@ -595,7 +596,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           api.flutterMethods,
           apiName: api.name,
         ))
-        ..fields.addAll(_proxyApiInterfaceApiFields(interfacesApis))
+        ..fields.addAll(_proxyApiInterfaceApiFields(apisOfInterfaces))
         ..fields.addAll(_proxyApiAttachedFields(api.attachedFields))
         ..methods.add(
           _proxyApiSetUpMessageHandlerMethod(
@@ -627,11 +628,11 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           codecName: codecName,
         ))
         ..methods.add(_proxyApiCopyMethod(
-          flutterMethods: api.flutterMethods,
-          flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
           apiName: api.name,
           unattachedFields: api.unattachedFields,
-          interfacesApis: interfacesApis,
+          declaredAndInheritedFlutterMethods: flutterMethodsFromSuperClasses
+              .followedBy(flutterMethodsFromInterfaces)
+              .followedBy(api.flutterMethods),
         )),
     );
 
@@ -1315,9 +1316,9 @@ if (${_varNamePrefix}replyList == null) {
   /// inherited from apis that are being implemented (following the `implements`
   /// keyword).
   Iterable<cb.Field> _proxyApiInterfaceApiFields(
-    Iterable<AstProxyApi> apis,
+    Iterable<AstProxyApi> apisOfInterfaces,
   ) sync* {
-    for (final AstProxyApi proxyApi in apis) {
+    for (final AstProxyApi proxyApi in apisOfInterfaces) {
       for (final Method method in proxyApi.methods) {
         yield cb.Field(
           (cb.FieldBuilder builder) => builder
@@ -1770,11 +1771,9 @@ if (${_varNamePrefix}replyList == null) {
   /// and unattached fields passed to the new instance. This method is inherited
   /// from the base ProxyApi class.
   cb.Method _proxyApiCopyMethod({
-    required Iterable<Method> flutterMethods,
-    required Iterable<Method> flutterMethodsFromSuperClasses,
     required String apiName,
     required Iterable<ApiField> unattachedFields,
-    required Iterable<AstProxyApi> interfacesApis,
+    required Iterable<Method> declaredAndInheritedFlutterMethods,
   }) {
     return cb.Method(
       (cb.MethodBuilder builder) => builder
@@ -1792,12 +1791,8 @@ if (${_varNamePrefix}replyList == null) {
                   _instanceManagerVarName: cb.refer(_instanceManagerVarName),
                   for (final ApiField field in unattachedFields)
                     field.name: cb.refer(field.name),
-                  for (final Method method in flutterMethodsFromSuperClasses)
-                    method.name: cb.refer(method.name),
-                  for (final AstProxyApi proxyApi in interfacesApis)
-                    for (final Method method in proxyApi.methods)
-                      method.name: cb.refer(method.name),
-                  for (final Method method in flutterMethods)
+                  for (final Method method
+                      in declaredAndInheritedFlutterMethods)
                     method.name: cb.refer(method.name),
                 },
               )

From 0caa96372bf2971c98cd43fd80f20183e3dee24e Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 15:11:34 -0500
Subject: [PATCH 25/32] add protected for more methods

---
 packages/pigeon/lib/dart/templates.dart       |  2 +
 packages/pigeon/lib/dart_generator.dart       |  7 ++-
 .../src/generated/proxy_api_tests.gen.dart    | 63 ++++++++++---------
 3 files changed, 40 insertions(+), 32 deletions(-)

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index 5da28beafc30..6de2a11ee9a4 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -344,9 +344,11 @@ abstract class $proxyApiBaseClassName {
   ///
   /// If it is null, the default BinaryMessenger will be used, which routes to
   /// the host platform.
+  @protected
   final BinaryMessenger? $_proxyApiBaseClassMessengerVarName;
 
   /// Maintains instances stored to communicate with native language objects.
+  @protected
   final $instanceManagerClassName $_proxyApiBaseClassInstanceManagerVarName;
 
   /// Instantiates and returns a functionally identical object to oneself.
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 4cb24e0ab61b..a9b1eac032be 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -1170,11 +1170,12 @@ if (${_varNamePrefix}replyList == null) {
       (cb.ConstructorBuilder builder) => builder
         ..name = '${classMemberNamePrefix}detached'
         ..docs.addAll(<String>[
-          '/// Constructs $apiName without creating the associated native object.',
+          '/// Constructs [$apiName] without creating the associated native object.',
           '///',
           '/// This should only be used by subclasses created by this library or to',
           '/// create copies for an [$instanceManagerClassName].',
         ])
+        ..annotations.add(cb.refer('protected'))
         ..optionalParameters.addAll(<cb.Parameter>[
           binaryMessengerParameter,
           instanceManagerParameter,
@@ -1226,7 +1227,7 @@ if (${_varNamePrefix}replyList == null) {
     );
   }
 
-  /// Converts unattached constructors from the pigeon AST to `code_builder`
+  /// Converts unattached fields from the pigeon AST to `code_builder`
   /// Fields.
   Iterable<cb.Field> _proxyApiUnattachedFields(
     Iterable<ApiField> fields,
@@ -1279,7 +1280,7 @@ if (${_varNamePrefix}replyList == null) {
                 ');',
                 '```',
                 '',
-                'Alternatively, `$instanceManagerClassName.removeWeakReference` can be used to',
+                'Alternatively, [$instanceManagerClassName.removeWeakReference] can be used to',
                 'release the associated Native object manually.',
               ],
             ],
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index 68b02de3c24e..8675499b8022 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -50,9 +50,11 @@ abstract class Pigeon_ProxyApiBaseClass {
   ///
   /// If it is null, the default BinaryMessenger will be used, which routes to
   /// the host platform.
+  @protected
   final BinaryMessenger? pigeon_binaryMessenger;
 
   /// Maintains instances stored to communicate with native language objects.
+  @protected
   final Pigeon_InstanceManager pigeon_instanceManager;
 
   /// Instantiates and returns a functionally identical object to oneself.
@@ -533,10 +535,11 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     }();
   }
 
-  /// Constructs ProxyApiTestClass without creating the associated native object.
+  /// Constructs [ProxyApiTestClass] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
   /// create copies for an [Pigeon_InstanceManager].
+  @protected
   ProxyApiTestClass.pigeon_detached({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
@@ -644,7 +647,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiTestClass pigeon_instance)? flutterNoop;
 
@@ -666,7 +669,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError;
 
@@ -688,7 +691,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiTestClass pigeon_instance)?
       flutterThrowErrorFromVoid;
@@ -711,7 +714,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final bool Function(
     ProxyApiTestClass pigeon_instance,
@@ -736,7 +739,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final int Function(
     ProxyApiTestClass pigeon_instance,
@@ -761,7 +764,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final double Function(
     ProxyApiTestClass pigeon_instance,
@@ -786,7 +789,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final String Function(
     ProxyApiTestClass pigeon_instance,
@@ -811,7 +814,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Uint8List Function(
     ProxyApiTestClass pigeon_instance,
@@ -836,7 +839,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<Object?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -862,7 +865,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<ProxyApiTestClass?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -887,7 +890,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, Object?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -913,7 +916,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, ProxyApiTestClass?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -938,7 +941,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final AnEnum Function(
     ProxyApiTestClass pigeon_instance,
@@ -963,7 +966,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiSuperClass Function(
     ProxyApiTestClass pigeon_instance,
@@ -988,7 +991,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final bool? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1013,7 +1016,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final int? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1038,7 +1041,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final double? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1063,7 +1066,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final String? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1088,7 +1091,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Uint8List? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1113,7 +1116,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<Object?>? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1138,7 +1141,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, Object?>? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1163,7 +1166,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final AnEnum? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1188,7 +1191,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiSuperClass? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1214,7 +1217,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Future<void> Function(ProxyApiTestClass pigeon_instance)?
       flutterNoopAsync;
@@ -1237,7 +1240,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Future<String> Function(
     ProxyApiTestClass pigeon_instance,
@@ -4819,10 +4822,11 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
     }();
   }
 
-  /// Constructs ProxyApiSuperClass without creating the associated native object.
+  /// Constructs [ProxyApiSuperClass] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
   /// create copies for an [Pigeon_InstanceManager].
+  @protected
   ProxyApiSuperClass.pigeon_detached({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
@@ -4917,10 +4921,11 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
 
 /// ProxyApi to serve as an interface to the core ProxyApi interface.
 class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
-  /// Constructs ProxyApiInterface without creating the associated native object.
+  /// Constructs [ProxyApiInterface] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
   /// create copies for an [Pigeon_InstanceManager].
+  @protected
   ProxyApiInterface.pigeon_detached({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
@@ -4943,7 +4948,7 @@ class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
   /// );
   /// ```
   ///
-  /// Alternatively, `Pigeon_InstanceManager.removeWeakReference` can be used to
+  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod;
 

From 1c61c5110f1de50cd5effe3883c7e80126d3fc7c Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Fri, 2 Feb 2024 15:46:17 -0500
Subject: [PATCH 26/32] improvement of docs

---
 packages/pigeon/lib/dart_generator.dart       | 18 ++++++++----
 packages/pigeon/lib/pigeon_lib.dart           |  2 +-
 .../src/generated/proxy_api_tests.gen.dart    | 28 ++-----------------
 3 files changed, 15 insertions(+), 33 deletions(-)

diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index a9b1eac032be..966c9dcf0452 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -1263,8 +1263,12 @@ if (${_varNamePrefix}replyList == null) {
             <String>[
               ...method.documentationComments,
               ...<String>[
-                if (method.documentationComments.isNotEmpty) '',
-                'Dart:',
+                if (method.documentationComments.isNotEmpty)
+                  ''
+                else ...<String>[
+                  'Callback method.',
+                  '',
+                ],
                 'For the associated Native object to be automatically garbage collected,',
                 "it is required that the implementation of this `Function` doesn't have a",
                 'strong reference to the encapsulating class instance. When this `Function`',
@@ -1399,6 +1403,8 @@ if (${_varNamePrefix}replyList == null) {
     required Iterable<ApiField> unattachedFields,
     required bool hasCallbackConstructor,
   }) {
+    final bool hasAnyMessageHandlers =
+        hasCallbackConstructor || flutterMethods.isNotEmpty;
     return cb.Method.returnsVoid(
       (cb.MethodBuilder builder) => builder
         ..name = '${classMemberNamePrefix}setUpMessageHandlers'
@@ -1469,7 +1475,7 @@ if (${_varNamePrefix}replyList == null) {
             ),
         ])
         ..body = cb.Block.of(<cb.Code>[
-          if (hasCallbackConstructor || flutterMethods.isNotEmpty) ...<cb.Code>[
+          if (hasAnyMessageHandlers) ...<cb.Code>[
             cb.Code(
               'final $codecName $_pigeonChannelCodec = $codecName($_instanceManagerVarName ?? $instanceManagerClassName.instance);',
             ),
@@ -1581,11 +1587,11 @@ if (${_varNamePrefix}replyList == null) {
     );
   }
 
-  /// Converts attached fields from the pigeon AST to `code_builder` fields.
+  /// Converts attached fields from the pigeon AST to `code_builder` Methods.
   ///
   /// These private methods are used to lazily instantiate attached fields. The
   /// instance is created and returned synchronously while the native instance
-  /// is created synchronously. This is similar to how constructors work.
+  /// is created asynchronously. This is similar to how constructors work.
   Iterable<cb.Method> _proxyApiAttachedFieldMethods(
     Iterable<ApiField> fields, {
     required String apiName,
@@ -1675,7 +1681,7 @@ if (${_varNamePrefix}replyList == null) {
     }
   }
 
-  /// Converts host methods from pigeon AST to `code_builder` AST.
+  /// Converts host methods from pigeon AST to `code_builder` Methods.
   ///
   /// This creates methods like a HostApi except that it includes the calling
   /// instance if the method is not static.
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 65cabf04ef37..eedd8a9f9a81 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -1029,7 +1029,7 @@ List<Error> _validateProxyApi(
     }
 
     // Validate this api isn't used as an interface and contains anything except
-    // Flutter methods or a static host method.
+    // Flutter methods, a static host method, attached methods.
     final bool isValidInterfaceProxyApi = api.constructors.isEmpty &&
         api.fields.where((ApiField field) => !field.isStatic).isEmpty &&
         api.hostMethods.where((Method method) => !method.isStatic).isEmpty;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index 8675499b8022..c3b3e849aad1 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -631,7 +631,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// A no-op function taking no arguments and returning no value, to sanity
   /// test basic calling.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -653,7 +652,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Responds with an error from an async function returning a value.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -675,7 +673,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Responds with an error from an async void function.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -698,7 +695,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed boolean, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -723,7 +719,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed int, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -748,7 +743,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed double, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -773,7 +767,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed string, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -798,7 +791,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed byte list, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -823,7 +815,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -849,7 +840,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed list with ProxyApis, to test serialization and
   /// deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -874,7 +864,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed map, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -900,7 +889,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed map with ProxyApis, to test serialization and
   /// deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -925,7 +913,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -950,7 +937,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -975,7 +961,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed boolean, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1000,7 +985,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed int, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1025,7 +1009,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed double, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1050,7 +1033,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed string, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1075,7 +1057,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed byte list, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1100,7 +1081,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1125,7 +1105,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed map, to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1150,7 +1129,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1175,7 +1153,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1201,7 +1178,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// A no-op function taking no arguments and returning no value, to sanity
   /// test basic asynchronous calling.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -1224,7 +1200,6 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in generic Object asynchronously.
   ///
-  /// Dart:
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
@@ -4932,7 +4907,8 @@ class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
     this.anInterfaceMethod,
   });
 
-  /// Dart:
+  /// Callback method.
+  ///
   /// For the associated Native object to be automatically garbage collected,
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`

From cb2e6546b65d2e24d364429197475c4e8058bd32 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Sun, 4 Feb 2024 11:10:36 -0500
Subject: [PATCH 27/32] change enum name

---
 packages/pigeon/pigeons/proxy_api_tests.dart  | 27 +++---
 .../src/generated/proxy_api_tests.gen.dart    | 82 ++++++++++---------
 2 files changed, 57 insertions(+), 52 deletions(-)

diff --git a/packages/pigeon/pigeons/proxy_api_tests.dart b/packages/pigeon/pigeons/proxy_api_tests.dart
index 51c351ab556a..1976af972d32 100644
--- a/packages/pigeon/pigeons/proxy_api_tests.dart
+++ b/packages/pigeon/pigeons/proxy_api_tests.dart
@@ -4,7 +4,7 @@
 
 import 'package:pigeon/pigeon.dart';
 
-enum AnEnum {
+enum ProxyApiTestEnum {
   one,
   two,
   three,
@@ -31,7 +31,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
     // ignore: avoid_unused_constructor_parameters
     Map<String?, Object?> mapParam,
     // ignore: avoid_unused_constructor_parameters
-    AnEnum enumParam,
+    ProxyApiTestEnum enumParam,
     // ignore: avoid_unused_constructor_parameters
     ProxyApiSuperClass proxyApiParam,
     // ignore: avoid_unused_constructor_parameters
@@ -49,7 +49,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
     // ignore: avoid_unused_constructor_parameters
     Map<String?, Object?>? nullableMapParam,
     // ignore: avoid_unused_constructor_parameters
-    AnEnum? nullableEnumParam,
+    ProxyApiTestEnum? nullableEnumParam,
     // ignore: avoid_unused_constructor_parameters
     ProxyApiSuperClass? nullableProxyApiParam,
   );
@@ -61,7 +61,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   late Uint8List aUint8List;
   late List<Object?> aList;
   late Map<String?, Object?> aMap;
-  late AnEnum anEnum;
+  late ProxyApiTestEnum anEnum;
   late ProxyApiSuperClass aProxyApi;
 
   late bool? aNullableBool;
@@ -71,7 +71,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   late Uint8List? aNullableUint8List;
   late List<Object?>? aNullableList;
   late Map<String?, Object?>? aNullableMap;
-  late AnEnum? aNullableEnum;
+  late ProxyApiTestEnum? aNullableEnum;
   late ProxyApiSuperClass? aNullableProxyApi;
 
   @attached
@@ -125,7 +125,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
       Map<String?, ProxyApiTestClass?> aMap)? flutterEchoProxyApiMap;
 
   /// Returns the passed enum to test serialization and deserialization.
-  late AnEnum Function(AnEnum anEnum)? flutterEchoEnum;
+  late ProxyApiTestEnum Function(ProxyApiTestEnum anEnum)? flutterEchoEnum;
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   late ProxyApiSuperClass Function(ProxyApiSuperClass aProxyApi)?
@@ -156,7 +156,8 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
       flutterEchoNullableMap;
 
   /// Returns the passed enum to test serialization and deserialization.
-  late AnEnum? Function(AnEnum? anEnum)? flutterEchoNullableEnum;
+  late ProxyApiTestEnum? Function(ProxyApiTestEnum? anEnum)?
+      flutterEchoNullableEnum;
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   late ProxyApiSuperClass? Function(ProxyApiSuperClass? aProxyApi)?
@@ -228,7 +229,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   );
 
   /// Returns the passed enum to test serialization and deserialization.
-  AnEnum echoEnum(AnEnum anEnum);
+  ProxyApiTestEnum echoEnum(ProxyApiTestEnum anEnum);
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   ProxyApiSuperClass echoProxyApi(ProxyApiSuperClass aProxyApi);
@@ -259,7 +260,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed map, to test serialization and deserialization.
   Map<String?, Object?>? echoNullableMap(Map<String?, Object?>? aNullableMap);
 
-  AnEnum? echoNullableEnum(AnEnum? aNullableEnum);
+  ProxyApiTestEnum? echoNullableEnum(ProxyApiTestEnum? aNullableEnum);
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   ProxyApiSuperClass? echoNullableProxyApi(
@@ -307,7 +308,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
   @async
-  AnEnum echoAsyncEnum(AnEnum anEnum);
+  ProxyApiTestEnum echoAsyncEnum(ProxyApiTestEnum anEnum);
 
   /// Responds with an error from an async function returning a value.
   @async
@@ -355,7 +356,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
   @async
-  AnEnum? echoAsyncNullableEnum(AnEnum? anEnum);
+  ProxyApiTestEnum? echoAsyncNullableEnum(ProxyApiTestEnum? anEnum);
 
   // ========== Static method test ==========
 
@@ -410,7 +411,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
       Map<String?, ProxyApiTestClass?> aMap);
 
   @async
-  AnEnum callFlutterEchoEnum(AnEnum anEnum);
+  ProxyApiTestEnum callFlutterEchoEnum(ProxyApiTestEnum anEnum);
 
   @async
   ProxyApiSuperClass callFlutterEchoProxyApi(ProxyApiSuperClass aProxyApi);
@@ -439,7 +440,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   );
 
   @async
-  AnEnum? callFlutterEchoNullableEnum(AnEnum? anEnum);
+  ProxyApiTestEnum? callFlutterEchoNullableEnum(ProxyApiTestEnum? anEnum);
 
   @async
   ProxyApiSuperClass? callFlutterEchoNullableProxyApi(
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index c3b3e849aad1..1057954190e9 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -391,7 +391,7 @@ class _Pigeon_ProxyApiBaseCodec extends StandardMessageCodec {
   }
 }
 
-enum AnEnum {
+enum ProxyApiTestEnum {
   one,
   two,
   three,
@@ -455,7 +455,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     required Uint8List aUint8ListParam,
     required List<Object?> listParam,
     required Map<String?, Object?> mapParam,
-    required AnEnum enumParam,
+    required ProxyApiTestEnum enumParam,
     required ProxyApiSuperClass proxyApiParam,
     bool? nullableBoolParam,
     int? nullableIntParam,
@@ -464,7 +464,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     Uint8List? nullableUint8ListParam,
     List<Object?>? nullableListParam,
     Map<String?, Object?>? nullableMapParam,
-    AnEnum? nullableEnumParam,
+    ProxyApiTestEnum? nullableEnumParam,
     ProxyApiSuperClass? nullableProxyApiParam,
   }) : super.pigeon_detached() {
     final int __pigeon_instanceIdentifier =
@@ -606,7 +606,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   final Map<String?, Object?> aMap;
 
-  final AnEnum anEnum;
+  final ProxyApiTestEnum anEnum;
 
   final ProxyApiSuperClass aProxyApi;
 
@@ -624,7 +624,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   final Map<String?, Object?>? aNullableMap;
 
-  final AnEnum? aNullableEnum;
+  final ProxyApiTestEnum? aNullableEnum;
 
   final ProxyApiSuperClass? aNullableProxyApi;
 
@@ -930,9 +930,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   ///
   /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
-  final AnEnum Function(
+  final ProxyApiTestEnum Function(
     ProxyApiTestClass pigeon_instance,
-    AnEnum anEnum,
+    ProxyApiTestEnum anEnum,
   )? flutterEchoEnum;
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
@@ -1146,9 +1146,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   ///
   /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
-  final AnEnum? Function(
+  final ProxyApiTestEnum? Function(
     ProxyApiTestClass pigeon_instance,
-    AnEnum? anEnum,
+    ProxyApiTestEnum? anEnum,
   )? flutterEchoNullableEnum;
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
@@ -1242,7 +1242,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       Uint8List aUint8List,
       List<Object?> aList,
       Map<String?, Object?> aMap,
-      AnEnum anEnum,
+      ProxyApiTestEnum anEnum,
       ProxyApiSuperClass aProxyApi,
       bool? aNullableBool,
       int? aNullableInt,
@@ -1251,7 +1251,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       Uint8List? aNullableUint8List,
       List<Object?>? aNullableList,
       Map<String?, Object?>? aNullableMap,
-      AnEnum? aNullableEnum,
+      ProxyApiTestEnum? aNullableEnum,
       ProxyApiSuperClass? aNullableProxyApi,
     )? pigeon_newInstance,
     void Function(ProxyApiTestClass pigeon_instance)? flutterNoop,
@@ -1293,9 +1293,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       ProxyApiTestClass pigeon_instance,
       Map<String?, ProxyApiTestClass?> aMap,
     )? flutterEchoProxyApiMap,
-    AnEnum Function(
+    ProxyApiTestEnum Function(
       ProxyApiTestClass pigeon_instance,
-      AnEnum anEnum,
+      ProxyApiTestEnum anEnum,
     )? flutterEchoEnum,
     ProxyApiSuperClass Function(
       ProxyApiTestClass pigeon_instance,
@@ -1329,9 +1329,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       ProxyApiTestClass pigeon_instance,
       Map<String?, Object?>? aMap,
     )? flutterEchoNullableMap,
-    AnEnum? Function(
+    ProxyApiTestEnum? Function(
       ProxyApiTestClass pigeon_instance,
-      AnEnum? anEnum,
+      ProxyApiTestEnum? anEnum,
     )? flutterEchoNullableEnum,
     ProxyApiSuperClass? Function(
       ProxyApiTestClass pigeon_instance,
@@ -1386,10 +1386,10 @@ class ProxyApiTestClass extends ProxyApiSuperClass
               (args[7] as Map<Object?, Object?>?)?.cast<String?, Object?>();
           assert(arg_aMap != null,
               'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null Map<String?, Object?>.');
-          final AnEnum? arg_anEnum =
-              args[8] == null ? null : AnEnum.values[args[8]! as int];
+          final ProxyApiTestEnum? arg_anEnum =
+              args[8] == null ? null : ProxyApiTestEnum.values[args[8]! as int];
           assert(arg_anEnum != null,
-              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null AnEnum.');
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.pigeon_newInstance was null, expected non-null ProxyApiTestEnum.');
           final ProxyApiSuperClass? arg_aProxyApi =
               (args[9] as ProxyApiSuperClass?);
           assert(arg_aProxyApi != null,
@@ -1403,8 +1403,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
               (args[15] as List<Object?>?)?.cast<Object?>();
           final Map<String?, Object?>? arg_aNullableMap =
               (args[16] as Map<Object?, Object?>?)?.cast<String?, Object?>();
-          final AnEnum? arg_aNullableEnum =
-              args[17] == null ? null : AnEnum.values[args[17]! as int];
+          final ProxyApiTestEnum? arg_aNullableEnum = args[17] == null
+              ? null
+              : ProxyApiTestEnum.values[args[17]! as int];
           final ProxyApiSuperClass? arg_aNullableProxyApi =
               (args[18] as ProxyApiSuperClass?);
           try {
@@ -1897,12 +1898,12 @@ class ProxyApiTestClass extends ProxyApiSuperClass
               (args[0] as ProxyApiTestClass?);
           assert(arg_pigeon_instance != null,
               'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null, expected non-null ProxyApiTestClass.');
-          final AnEnum? arg_anEnum =
-              args[1] == null ? null : AnEnum.values[args[1]! as int];
+          final ProxyApiTestEnum? arg_anEnum =
+              args[1] == null ? null : ProxyApiTestEnum.values[args[1]! as int];
           assert(arg_anEnum != null,
-              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null, expected non-null AnEnum.');
+              'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoEnum was null, expected non-null ProxyApiTestEnum.');
           try {
-            final AnEnum? output =
+            final ProxyApiTestEnum? output =
                 (flutterEchoEnum ?? arg_pigeon_instance!.flutterEchoEnum)
                     ?.call(arg_pigeon_instance!, arg_anEnum!);
             return wrapResponse(result: output?.index);
@@ -2202,10 +2203,10 @@ class ProxyApiTestClass extends ProxyApiSuperClass
               (args[0] as ProxyApiTestClass?);
           assert(arg_pigeon_instance != null,
               'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.flutterEchoNullableEnum was null, expected non-null ProxyApiTestClass.');
-          final AnEnum? arg_anEnum =
-              args[1] == null ? null : AnEnum.values[args[1]! as int];
+          final ProxyApiTestEnum? arg_anEnum =
+              args[1] == null ? null : ProxyApiTestEnum.values[args[1]! as int];
           try {
-            final AnEnum? output = (flutterEchoNullableEnum ??
+            final ProxyApiTestEnum? output = (flutterEchoNullableEnum ??
                     arg_pigeon_instance!.flutterEchoNullableEnum)
                 ?.call(arg_pigeon_instance!, arg_anEnum);
             return wrapResponse(result: output?.index);
@@ -2843,7 +2844,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   /// Returns the passed enum to test serialization and deserialization.
-  Future<AnEnum> echoEnum(AnEnum anEnum) async {
+  Future<ProxyApiTestEnum> echoEnum(ProxyApiTestEnum anEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -2871,7 +2872,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
         message: 'Host platform returned null value for non-null return value.',
       );
     } else {
-      return AnEnum.values[__pigeon_replyList[0]! as int];
+      return ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 
@@ -3135,7 +3136,8 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     }
   }
 
-  Future<AnEnum?> echoNullableEnum(AnEnum? aNullableEnum) async {
+  Future<ProxyApiTestEnum?> echoNullableEnum(
+      ProxyApiTestEnum? aNullableEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -3160,7 +3162,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     } else {
       return (__pigeon_replyList[0] as int?) == null
           ? null
-          : AnEnum.values[__pigeon_replyList[0]! as int];
+          : ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 
@@ -3488,7 +3490,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
-  Future<AnEnum> echoAsyncEnum(AnEnum anEnum) async {
+  Future<ProxyApiTestEnum> echoAsyncEnum(ProxyApiTestEnum anEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -3516,7 +3518,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
         message: 'Host platform returned null value for non-null return value.',
       );
     } else {
-      return AnEnum.values[__pigeon_replyList[0]! as int];
+      return ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 
@@ -3831,7 +3833,8 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
-  Future<AnEnum?> echoAsyncNullableEnum(AnEnum? anEnum) async {
+  Future<ProxyApiTestEnum?> echoAsyncNullableEnum(
+      ProxyApiTestEnum? anEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -3856,7 +3859,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     } else {
       return (__pigeon_replyList[0] as int?) == null
           ? null
-          : AnEnum.values[__pigeon_replyList[0]! as int];
+          : ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 
@@ -4334,7 +4337,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     }
   }
 
-  Future<AnEnum> callFlutterEchoEnum(AnEnum anEnum) async {
+  Future<ProxyApiTestEnum> callFlutterEchoEnum(ProxyApiTestEnum anEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -4362,7 +4365,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
         message: 'Host platform returned null value for non-null return value.',
       );
     } else {
-      return AnEnum.values[__pigeon_replyList[0]! as int];
+      return ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 
@@ -4592,7 +4595,8 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     }
   }
 
-  Future<AnEnum?> callFlutterEchoNullableEnum(AnEnum? anEnum) async {
+  Future<ProxyApiTestEnum?> callFlutterEchoNullableEnum(
+      ProxyApiTestEnum? anEnum) async {
     final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
@@ -4617,7 +4621,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     } else {
       return (__pigeon_replyList[0] as int?) == null
           ? null
-          : AnEnum.values[__pigeon_replyList[0]! as int];
+          : ProxyApiTestEnum.values[__pigeon_replyList[0]! as int];
     }
   }
 

From 12d9c7d30beb387d5635b2bde5fb26e8f7faec98 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Sun, 4 Feb 2024 13:15:51 -0500
Subject: [PATCH 28/32] dont gen method without apis

---
 packages/pigeon/lib/objc_generator.dart | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index bc26495e650b..6effa34ee6cf 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -715,7 +715,10 @@ class ObjcSourceGenerator extends StructuredGenerator<ObjcOptions> {
       _writeCreateConnectionError(indent);
       indent.newln();
     }
-    _writeGetNullableObjectAtIndex(indent);
+
+    if (hasHostApi || hasFlutterApi) {
+      _writeGetNullableObjectAtIndex(indent);
+    }
   }
 
   void _writeWrapError(Indent indent) {

From c0aa558af3db39ceaa307ab83d551e312e3fb66c Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Tue, 27 Feb 2024 15:38:43 -0500
Subject: [PATCH 29/32] fix class name generation without underscore

---
 .../example/app/lib/src/messages.g.dart       |   2 +-
 packages/pigeon/lib/dart_generator.dart       |   5 +-
 packages/pigeon/lib/generator_tools.dart      |   2 +-
 .../background_platform_channels.gen.dart     |   2 +-
 .../lib/src/generated/core_tests.gen.dart     |   2 +-
 .../lib/src/generated/enum.gen.dart           |   2 +-
 .../src/generated/flutter_unittests.gen.dart  |   2 +-
 .../lib/src/generated/message.gen.dart        |   2 +-
 .../lib/src/generated/multiple_arity.gen.dart |   2 +-
 .../src/generated/non_null_fields.gen.dart    |   2 +-
 .../lib/src/generated/null_fields.gen.dart    |   2 +-
 .../src/generated/nullable_returns.gen.dart   |   2 +-
 .../lib/src/generated/primitive.gen.dart      |   2 +-
 .../src/generated/proxy_api_tests.gen.dart    | 384 +++++++++---------
 .../test/instance_manager_test.dart           |  36 +-
 packages/pigeon/test/dart/proxy_api_test.dart |  18 +-
 16 files changed, 232 insertions(+), 235 deletions(-)

diff --git a/packages/pigeon/example/app/lib/src/messages.g.dart b/packages/pigeon/example/app/lib/src/messages.g.dart
index 961e9c5856b5..59213e4ef2bb 100644
--- a/packages/pigeon/example/app/lib/src/messages.g.dart
+++ b/packages/pigeon/example/app/lib/src/messages.g.dart
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 966c9dcf0452..9e59fecf4804 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -102,10 +102,7 @@ class DartGenerator extends StructuredGenerator<DartOptions> {
     indent.writeln('// ${getGeneratedCodeWarning()}');
     indent.writeln('// $seeAlsoWarning');
     indent.writeln(
-      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, '
-      'avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, '
-      'omit_local_variable_types, unused_shown_name, unnecessary_import, '
-      'no_leading_underscores_for_local_identifiers, camel_case_types',
+      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers',
     );
     indent.newln();
   }
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 1954dad7f9bd..f60fdcbc4cc4 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -299,7 +299,7 @@ const String seeAlsoWarning = 'See also: https://pub.dev/packages/pigeon';
 ///
 /// This lowers the chances of variable name collisions with user defined
 /// parameters.
-const String classNamePrefix = 'Pigeon_';
+const String classNamePrefix = 'Pigeon';
 
 /// Name for the generated InstanceManager for ProxyApis.
 ///
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
index 91dee132ceba..7222e263b32b 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/background_platform_channels.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index e0ff30162031..98c1aea5c084 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
index b58d7d652834..c585d3a83259 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
index 99cbf7fa3711..73f100cf28b6 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
index 04dbc6d43a2a..cc7b8b53c360 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
index 19455117087d..bec054b4be49 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
index be9c48422aef..7279e85c40ea 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/non_null_fields.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
index bc18ccd0ada0..ecf7c7f7e970 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/null_fields.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
index d5c2bb3f63df..dd1665a463c1 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/nullable_returns.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
index b1f618a72b6e..72c115d65278 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/primitive.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index 1057954190e9..6aa044710aef 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -4,7 +4,7 @@
 //
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers, camel_case_types
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
@@ -38,13 +38,13 @@ List<Object?> wrapResponse(
 /// All implementers are expected to be [immutable] as defined by the annotation
 /// and override [pigeon_copy] returning an instance of itself.
 @immutable
-abstract class Pigeon_ProxyApiBaseClass {
-  /// Construct a [Pigeon_ProxyApiBaseClass].
-  Pigeon_ProxyApiBaseClass({
+abstract class PigeonProxyApiBaseClass {
+  /// Construct a [PigeonProxyApiBaseClass].
+  PigeonProxyApiBaseClass({
     this.pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
   }) : pigeon_instanceManager =
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance;
+            pigeon_instanceManager ?? PigeonInstanceManager.instance;
 
   /// Sends and receives binary data across the Flutter platform barrier.
   ///
@@ -55,17 +55,17 @@ abstract class Pigeon_ProxyApiBaseClass {
 
   /// Maintains instances stored to communicate with native language objects.
   @protected
-  final Pigeon_InstanceManager pigeon_instanceManager;
+  final PigeonInstanceManager pigeon_instanceManager;
 
   /// Instantiates and returns a functionally identical object to oneself.
   ///
   /// Outside of tests, this method should only ever be called by
-  /// [Pigeon_InstanceManager].
+  /// [PigeonInstanceManager].
   ///
   /// Subclasses should always override their parent's implementation of this
   /// method.
   @protected
-  Pigeon_ProxyApiBaseClass pigeon_copy();
+  PigeonProxyApiBaseClass pigeon_copy();
 }
 
 /// Maintains instances used to communicate with the native objects they
@@ -83,9 +83,9 @@ abstract class Pigeon_ProxyApiBaseClass {
 /// is added as a weak reference with the same identifier. This prevents a
 /// scenario where the weak referenced instance was released and then later
 /// returned by the host platform.
-class Pigeon_InstanceManager {
-  /// Constructs a [Pigeon_InstanceManager].
-  Pigeon_InstanceManager({required void Function(int) onWeakReferenceRemoved}) {
+class PigeonInstanceManager {
+  /// Constructs a [PigeonInstanceManager].
+  PigeonInstanceManager({required void Function(int) onWeakReferenceRemoved}) {
     this.onWeakReferenceRemoved = (int identifier) {
       _weakInstances.remove(identifier);
       onWeakReferenceRemoved(identifier);
@@ -99,12 +99,12 @@ class Pigeon_InstanceManager {
   // 0 <= n < 2^16.
   static const int _maxDartCreatedIdentifier = 65536;
 
-  /// The default [Pigeon_InstanceManager] used by ProxyApis.
+  /// The default [PigeonInstanceManager] used by ProxyApis.
   ///
   /// On creation, this manager makes a call to clear the native
   /// InstanceManager. This is to prevent identifier conflicts after a host
   /// restart.
-  static final Pigeon_InstanceManager instance = _initInstance();
+  static final PigeonInstanceManager instance = _initInstance();
 
   // Expando is used because it doesn't prevent its keys from becoming
   // inaccessible. This allows the manager to efficiently retrieve an identifier
@@ -115,10 +115,10 @@ class Pigeon_InstanceManager {
   // by calling instanceManager.getIdentifier() inside of `==` while this was a
   // HashMap).
   final Expando<int> _identifiers = Expando<int>();
-  final Map<int, WeakReference<Pigeon_ProxyApiBaseClass>> _weakInstances =
-      <int, WeakReference<Pigeon_ProxyApiBaseClass>>{};
-  final Map<int, Pigeon_ProxyApiBaseClass> _strongInstances =
-      <int, Pigeon_ProxyApiBaseClass>{};
+  final Map<int, WeakReference<PigeonProxyApiBaseClass>> _weakInstances =
+      <int, WeakReference<PigeonProxyApiBaseClass>>{};
+  final Map<int, PigeonProxyApiBaseClass> _strongInstances =
+      <int, PigeonProxyApiBaseClass>{};
   late final Finalizer<int> _finalizer;
   int _nextIdentifier = 0;
 
@@ -126,17 +126,17 @@ class Pigeon_InstanceManager {
   /// or becomes inaccessible.
   late final void Function(int) onWeakReferenceRemoved;
 
-  static Pigeon_InstanceManager _initInstance() {
+  static PigeonInstanceManager _initInstance() {
     WidgetsFlutterBinding.ensureInitialized();
-    final _Pigeon_InstanceManagerApi api = _Pigeon_InstanceManagerApi();
-    // Clears the native `Pigeon_InstanceManager` on the initial use of the Dart one.
+    final _PigeonInstanceManagerApi api = _PigeonInstanceManagerApi();
+    // Clears the native `PigeonInstanceManager` on the initial use of the Dart one.
     api.clear();
-    final Pigeon_InstanceManager instanceManager = Pigeon_InstanceManager(
+    final PigeonInstanceManager instanceManager = PigeonInstanceManager(
       onWeakReferenceRemoved: (int identifier) {
         api.removeStrongReference(identifier);
       },
     );
-    _Pigeon_InstanceManagerApi.setUpMessageHandlers(
+    _PigeonInstanceManagerApi.setUpMessageHandlers(
         instanceManager: instanceManager);
     ProxyApiTestClass.pigeon_setUpMessageHandlers(
         pigeon_instanceManager: instanceManager);
@@ -155,7 +155,7 @@ class Pigeon_InstanceManager {
   /// Throws assertion error if the instance has already been added.
   ///
   /// Returns the randomly generated id of the [instance] added.
-  int addDartCreatedInstance(Pigeon_ProxyApiBaseClass instance) {
+  int addDartCreatedInstance(PigeonProxyApiBaseClass instance) {
     final int identifier = _nextUniqueIdentifier();
     _addInstanceWithIdentifier(instance, identifier);
     return identifier;
@@ -169,7 +169,7 @@ class Pigeon_InstanceManager {
   ///
   /// This does not remove the strong referenced instance associated with
   /// [instance]. This can be done with [remove].
-  int? removeWeakReference(Pigeon_ProxyApiBaseClass instance) {
+  int? removeWeakReference(PigeonProxyApiBaseClass instance) {
     final int? identifier = getIdentifier(instance);
     if (identifier == null) {
       return null;
@@ -191,7 +191,7 @@ class Pigeon_InstanceManager {
   ///
   /// This does not remove the weak referenced instance associated with
   /// [identifier]. This can be done with [removeWeakReference].
-  T? remove<T extends Pigeon_ProxyApiBaseClass>(int identifier) {
+  T? remove<T extends PigeonProxyApiBaseClass>(int identifier) {
     return _strongInstances.remove(identifier) as T?;
   }
 
@@ -207,19 +207,19 @@ class Pigeon_InstanceManager {
   ///
   /// This method also expects the host `InstanceManager` to have a strong
   /// reference to the instance the identifier is associated with.
-  T? getInstanceWithWeakReference<T extends Pigeon_ProxyApiBaseClass>(
+  T? getInstanceWithWeakReference<T extends PigeonProxyApiBaseClass>(
       int identifier) {
-    final Pigeon_ProxyApiBaseClass? weakInstance =
+    final PigeonProxyApiBaseClass? weakInstance =
         _weakInstances[identifier]?.target;
 
     if (weakInstance == null) {
-      final Pigeon_ProxyApiBaseClass? strongInstance =
+      final PigeonProxyApiBaseClass? strongInstance =
           _strongInstances[identifier];
       if (strongInstance != null) {
-        final Pigeon_ProxyApiBaseClass copy = strongInstance.pigeon_copy();
+        final PigeonProxyApiBaseClass copy = strongInstance.pigeon_copy();
         _identifiers[copy] = identifier;
         _weakInstances[identifier] =
-            WeakReference<Pigeon_ProxyApiBaseClass>(copy);
+            WeakReference<PigeonProxyApiBaseClass>(copy);
         _finalizer.attach(copy, identifier, detach: copy);
         return copy as T;
       }
@@ -230,7 +230,7 @@ class Pigeon_InstanceManager {
   }
 
   /// Retrieves the identifier associated with instance.
-  int? getIdentifier(Pigeon_ProxyApiBaseClass instance) {
+  int? getIdentifier(PigeonProxyApiBaseClass instance) {
     return _identifiers[instance];
   }
 
@@ -244,22 +244,22 @@ class Pigeon_InstanceManager {
   ///
   /// Returns unique identifier of the [instance] added.
   void addHostCreatedInstance(
-      Pigeon_ProxyApiBaseClass instance, int identifier) {
+      PigeonProxyApiBaseClass instance, int identifier) {
     _addInstanceWithIdentifier(instance, identifier);
   }
 
   void _addInstanceWithIdentifier(
-      Pigeon_ProxyApiBaseClass instance, int identifier) {
+      PigeonProxyApiBaseClass instance, int identifier) {
     assert(!containsIdentifier(identifier));
     assert(getIdentifier(instance) == null);
     assert(identifier >= 0);
 
     _identifiers[instance] = identifier;
     _weakInstances[identifier] =
-        WeakReference<Pigeon_ProxyApiBaseClass>(instance);
+        WeakReference<PigeonProxyApiBaseClass>(instance);
     _finalizer.attach(instance, identifier, detach: instance);
 
-    final Pigeon_ProxyApiBaseClass copy = instance.pigeon_copy();
+    final PigeonProxyApiBaseClass copy = instance.pigeon_copy();
     _identifiers[copy] = identifier;
     _strongInstances[identifier] = copy;
   }
@@ -280,10 +280,10 @@ class Pigeon_InstanceManager {
   }
 }
 
-/// Generated API for managing the Dart and native `Pigeon_InstanceManager`s.
-class _Pigeon_InstanceManagerApi {
-  /// Constructor for [_Pigeon_InstanceManagerApi ].
-  _Pigeon_InstanceManagerApi({BinaryMessenger? binaryMessenger})
+/// Generated API for managing the Dart and native `PigeonInstanceManager`s.
+class _PigeonInstanceManagerApi {
+  /// Constructor for [_PigeonInstanceManagerApi ].
+  _PigeonInstanceManagerApi({BinaryMessenger? binaryMessenger})
       : _binaryMessenger = binaryMessenger;
 
   final BinaryMessenger? _binaryMessenger;
@@ -293,10 +293,10 @@ class _Pigeon_InstanceManagerApi {
 
   static void setUpMessageHandlers({
     BinaryMessenger? binaryMessenger,
-    Pigeon_InstanceManager? instanceManager,
+    PigeonInstanceManager? instanceManager,
   }) {
     const String channelName =
-        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.removeStrongReference';
+        r'dev.flutter.pigeon.pigeon_integration_tests.PigeonInstanceManagerApi.removeStrongReference';
     final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
       channelName,
       pigeonChannelCodec,
@@ -312,14 +312,14 @@ class _Pigeon_InstanceManagerApi {
         identifier != null,
         r'Argument for $channelName, expected non-null int.',
       );
-      (instanceManager ?? Pigeon_InstanceManager.instance).remove(identifier!);
+      (instanceManager ?? PigeonInstanceManager.instance).remove(identifier!);
       return;
     });
   }
 
   Future<void> removeStrongReference(int identifier) async {
     const String channelName =
-        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.removeStrongReference';
+        r'dev.flutter.pigeon.pigeon_integration_tests.PigeonInstanceManagerApi.removeStrongReference';
     final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
       channelName,
       pigeonChannelCodec,
@@ -340,12 +340,12 @@ class _Pigeon_InstanceManagerApi {
     }
   }
 
-  /// Clear the native `Pigeon_InstanceManager`.
+  /// Clear the native `PigeonInstanceManager`.
   ///
   /// This is typically called after a hot restart.
   Future<void> clear() async {
     const String channelName =
-        r'dev.flutter.pigeon.pigeon_integration_tests.Pigeon_InstanceManagerApi.clear';
+        r'dev.flutter.pigeon.pigeon_integration_tests.PigeonInstanceManagerApi.clear';
     final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
       channelName,
       pigeonChannelCodec,
@@ -366,12 +366,12 @@ class _Pigeon_InstanceManagerApi {
   }
 }
 
-class _Pigeon_ProxyApiBaseCodec extends StandardMessageCodec {
-  const _Pigeon_ProxyApiBaseCodec(this.instanceManager);
-  final Pigeon_InstanceManager instanceManager;
+class _PigeonProxyApiBaseCodec extends StandardMessageCodec {
+  const _PigeonProxyApiBaseCodec(this.instanceManager);
+  final PigeonInstanceManager instanceManager;
   @override
   void writeValue(WriteBuffer buffer, Object? value) {
-    if (value is Pigeon_ProxyApiBaseClass) {
+    if (value is PigeonProxyApiBaseClass) {
       buffer.putUint8(128);
       writeValue(buffer, instanceManager.getIdentifier(value));
     } else {
@@ -469,7 +469,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }) : super.pigeon_detached() {
     final int __pigeon_instanceIdentifier =
         pigeon_instanceManager.addDartCreatedInstance(this);
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     () async {
@@ -538,7 +538,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Constructs [ProxyApiTestClass] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
-  /// create copies for an [Pigeon_InstanceManager].
+  /// create copies for an [PigeonInstanceManager].
   @protected
   ProxyApiTestClass.pigeon_detached({
     super.pigeon_binaryMessenger,
@@ -589,8 +589,8 @@ class ProxyApiTestClass extends ProxyApiSuperClass
     this.flutterEchoAsyncString,
   }) : super.pigeon_detached();
 
-  late final _Pigeon_ProxyApiBaseCodec __pigeon_codecProxyApiTestClass =
-      _Pigeon_ProxyApiBaseCodec(pigeon_instanceManager);
+  late final _PigeonProxyApiBaseCodec __pigeon_codecProxyApiTestClass =
+      _PigeonProxyApiBaseCodec(pigeon_instanceManager);
 
   final bool aBool;
 
@@ -646,7 +646,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiTestClass pigeon_instance)? flutterNoop;
 
@@ -667,7 +667,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Object? Function(ProxyApiTestClass pigeon_instance)? flutterThrowError;
 
@@ -688,7 +688,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiTestClass pigeon_instance)?
       flutterThrowErrorFromVoid;
@@ -710,7 +710,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final bool Function(
     ProxyApiTestClass pigeon_instance,
@@ -734,7 +734,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final int Function(
     ProxyApiTestClass pigeon_instance,
@@ -758,7 +758,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final double Function(
     ProxyApiTestClass pigeon_instance,
@@ -782,7 +782,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final String Function(
     ProxyApiTestClass pigeon_instance,
@@ -806,7 +806,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Uint8List Function(
     ProxyApiTestClass pigeon_instance,
@@ -830,7 +830,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<Object?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -855,7 +855,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<ProxyApiTestClass?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -879,7 +879,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, Object?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -904,7 +904,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, ProxyApiTestClass?> Function(
     ProxyApiTestClass pigeon_instance,
@@ -928,7 +928,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiTestEnum Function(
     ProxyApiTestClass pigeon_instance,
@@ -952,7 +952,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiSuperClass Function(
     ProxyApiTestClass pigeon_instance,
@@ -976,7 +976,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final bool? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1000,7 +1000,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final int? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1024,7 +1024,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final double? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1048,7 +1048,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final String? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1072,7 +1072,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Uint8List? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1096,7 +1096,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final List<Object?>? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1120,7 +1120,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Map<String?, Object?>? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1144,7 +1144,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiTestEnum? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1168,7 +1168,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final ProxyApiSuperClass? Function(
     ProxyApiTestClass pigeon_instance,
@@ -1193,7 +1193,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Future<void> Function(ProxyApiTestClass pigeon_instance)?
       flutterNoopAsync;
@@ -1215,7 +1215,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final Future<String> Function(
     ProxyApiTestClass pigeon_instance,
@@ -1233,7 +1233,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   static void pigeon_setUpMessageHandlers({
     bool pigeon_clearHandlers = false,
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
     ProxyApiTestClass Function(
       bool aBool,
       int anInt,
@@ -1343,9 +1343,9 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       String aString,
     )? flutterEchoAsyncString,
   }) {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
     {
       final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
@@ -1409,7 +1409,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
           final ProxyApiSuperClass? arg_aNullableProxyApi =
               (args[18] as ProxyApiSuperClass?);
           try {
-            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+            (pigeon_instanceManager ?? PigeonInstanceManager.instance)
                 .addHostCreatedInstance(
               pigeon_newInstance?.call(
                       arg_aBool!,
@@ -2327,7 +2327,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
       pigeon_binaryMessenger: pigeon_binaryMessenger,
       pigeon_instanceManager: pigeon_instanceManager,
     );
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     final int __pigeon_instanceIdentifier =
@@ -2361,11 +2361,11 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   static ProxyApiSuperClass __pigeon_staticAttachedField() {
     final ProxyApiSuperClass __pigeon_instance =
         ProxyApiSuperClass.pigeon_detached();
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(PigeonInstanceManager.instance);
     final BinaryMessenger __pigeon_binaryMessenger =
         ServicesBinding.instance.defaultBinaryMessenger;
-    final int __pigeon_instanceIdentifier = Pigeon_InstanceManager.instance
+    final int __pigeon_instanceIdentifier = PigeonInstanceManager.instance
         .addDartCreatedInstance(__pigeon_instance);
     () async {
       const String __pigeon_channelName =
@@ -2396,7 +2396,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// A no-op function taking no arguments and returning no value, to sanity
   /// test basic calling.
   Future<void> noop() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2424,7 +2424,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns an error, to test error handling.
   Future<Object?> throwError() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2452,7 +2452,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns an error from a void function, to test error handling.
   Future<void> throwErrorFromVoid() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2480,7 +2480,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns a Flutter error, to test error handling.
   Future<Object?> throwFlutterError() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2508,7 +2508,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in int.
   Future<int> echoInt(int anInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2541,7 +2541,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in double.
   Future<double> echoDouble(double aDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2574,7 +2574,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in boolean.
   Future<bool> echoBool(bool aBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2607,7 +2607,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in string.
   Future<String> echoString(String aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2640,7 +2640,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in Uint8List.
   Future<Uint8List> echoUint8List(Uint8List aUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2673,7 +2673,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in generic Object.
   Future<Object> echoObject(Object anObject) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2706,7 +2706,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test serialization and deserialization.
   Future<List<Object?>> echoList(List<Object?> aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2741,7 +2741,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// deserialization.
   Future<List<ProxyApiTestClass?>> echoProxyApiList(
       List<ProxyApiTestClass?> aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2775,7 +2775,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed map, to test serialization and deserialization.
   Future<Map<String?, Object?>> echoMap(Map<String?, Object?> aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2811,7 +2811,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// deserialization.
   Future<Map<String?, ProxyApiTestClass?>> echoProxyApiMap(
       Map<String?, ProxyApiTestClass?> aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2845,7 +2845,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum to test serialization and deserialization.
   Future<ProxyApiTestEnum> echoEnum(ProxyApiTestEnum anEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2878,7 +2878,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed ProxyApi to test serialization and deserialization.
   Future<ProxyApiSuperClass> echoProxyApi(ProxyApiSuperClass aProxyApi) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2911,7 +2911,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in int.
   Future<int?> echoNullableInt(int? aNullableInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2939,7 +2939,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in double.
   Future<double?> echoNullableDouble(double? aNullableDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2967,7 +2967,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in boolean.
   Future<bool?> echoNullableBool(bool? aNullableBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -2995,7 +2995,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in string.
   Future<String?> echoNullableString(String? aNullableString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3024,7 +3024,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed in Uint8List.
   Future<Uint8List?> echoNullableUint8List(
       Uint8List? aNullableUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3052,7 +3052,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in generic Object.
   Future<Object?> echoNullableObject(Object? aNullableObject) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3080,7 +3080,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test serialization and deserialization.
   Future<List<Object?>?> echoNullableList(List<Object?>? aNullableList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3109,7 +3109,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed map, to test serialization and deserialization.
   Future<Map<String?, Object?>?> echoNullableMap(
       Map<String?, Object?>? aNullableMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3138,7 +3138,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<ProxyApiTestEnum?> echoNullableEnum(
       ProxyApiTestEnum? aNullableEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3169,7 +3169,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed ProxyApi to test serialization and deserialization.
   Future<ProxyApiSuperClass?> echoNullableProxyApi(
       ProxyApiSuperClass? aNullableProxyApi) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3198,7 +3198,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// A no-op function taking no arguments and returning no value, to sanity
   /// test basic asynchronous calling.
   Future<void> noopAsync() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3226,7 +3226,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in int asynchronously.
   Future<int> echoAsyncInt(int anInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3259,7 +3259,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in double asynchronously.
   Future<double> echoAsyncDouble(double aDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3292,7 +3292,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in boolean asynchronously.
   Future<bool> echoAsyncBool(bool aBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3325,7 +3325,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed string asynchronously.
   Future<String> echoAsyncString(String aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3358,7 +3358,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in Uint8List asynchronously.
   Future<Uint8List> echoAsyncUint8List(Uint8List aUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3391,7 +3391,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in generic Object asynchronously.
   Future<Object> echoAsyncObject(Object anObject) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3424,7 +3424,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test asynchronous serialization and deserialization.
   Future<List<Object?>> echoAsyncList(List<Object?> aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3457,7 +3457,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed map, to test asynchronous serialization and deserialization.
   Future<Map<String?, Object?>> echoAsyncMap(Map<String?, Object?> aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3491,7 +3491,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
   Future<ProxyApiTestEnum> echoAsyncEnum(ProxyApiTestEnum anEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3524,7 +3524,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Responds with an error from an async function returning a value.
   Future<Object?> throwAsyncError() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3552,7 +3552,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Responds with an error from an async void function.
   Future<void> throwAsyncErrorFromVoid() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3580,7 +3580,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Responds with a Flutter error from an async function returning a value.
   Future<Object?> throwAsyncFlutterError() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3608,7 +3608,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in int asynchronously.
   Future<int?> echoAsyncNullableInt(int? anInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3636,7 +3636,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns passed in double asynchronously.
   Future<double?> echoAsyncNullableDouble(double? aDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3664,7 +3664,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in boolean asynchronously.
   Future<bool?> echoAsyncNullableBool(bool? aBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3692,7 +3692,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed string asynchronously.
   Future<String?> echoAsyncNullableString(String? aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3720,7 +3720,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in Uint8List asynchronously.
   Future<Uint8List?> echoAsyncNullableUint8List(Uint8List? aUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3748,7 +3748,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed in generic Object asynchronously.
   Future<Object?> echoAsyncNullableObject(Object? anObject) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3776,7 +3776,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   /// Returns the passed list, to test asynchronous serialization and deserialization.
   Future<List<Object?>?> echoAsyncNullableList(List<Object?>? aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3805,7 +3805,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed map, to test asynchronous serialization and deserialization.
   Future<Map<String?, Object?>?> echoAsyncNullableMap(
       Map<String?, Object?>? aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3835,7 +3835,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// Returns the passed enum, to test asynchronous serialization and deserialization.
   Future<ProxyApiTestEnum?> echoAsyncNullableEnum(
       ProxyApiTestEnum? anEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3865,11 +3865,11 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   static Future<void> staticNoop({
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
   }) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
         'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.staticNoop';
@@ -3897,11 +3897,11 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   static Future<String> echoStaticString(
     String aString, {
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
   }) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
         'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.echoStaticString';
@@ -3933,11 +3933,11 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   static Future<void> staticAsyncNoop({
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
   }) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
         'dev.flutter.pigeon.pigeon_integration_tests.ProxyApiTestClass.staticAsyncNoop';
@@ -3963,7 +3963,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<void> callFlutterNoop() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -3990,7 +3990,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<Object?> callFlutterThrowError() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4017,7 +4017,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<void> callFlutterThrowErrorFromVoid() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4044,7 +4044,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<bool> callFlutterEchoBool(bool aBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4076,7 +4076,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<int> callFlutterEchoInt(int anInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4108,7 +4108,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<double> callFlutterEchoDouble(double aDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4140,7 +4140,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<String> callFlutterEchoString(String aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4172,7 +4172,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<Uint8List> callFlutterEchoUint8List(Uint8List aUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4204,7 +4204,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<List<Object?>> callFlutterEchoList(List<Object?> aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4237,7 +4237,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<List<ProxyApiTestClass?>> callFlutterEchoProxyApiList(
       List<ProxyApiTestClass?> aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4271,7 +4271,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<Map<String?, Object?>> callFlutterEchoMap(
       Map<String?, Object?> aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4305,7 +4305,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<Map<String?, ProxyApiTestClass?>> callFlutterEchoProxyApiMap(
       Map<String?, ProxyApiTestClass?> aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4338,7 +4338,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<ProxyApiTestEnum> callFlutterEchoEnum(ProxyApiTestEnum anEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4371,7 +4371,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<ProxyApiSuperClass> callFlutterEchoProxyApi(
       ProxyApiSuperClass aProxyApi) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4403,7 +4403,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<bool?> callFlutterEchoNullableBool(bool? aBool) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4430,7 +4430,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<int?> callFlutterEchoNullableInt(int? anInt) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4457,7 +4457,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<double?> callFlutterEchoNullableDouble(double? aDouble) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4484,7 +4484,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<String?> callFlutterEchoNullableString(String? aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4512,7 +4512,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<Uint8List?> callFlutterEchoNullableUint8List(
       Uint8List? aUint8List) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4540,7 +4540,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<List<Object?>?> callFlutterEchoNullableList(
       List<Object?>? aList) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4568,7 +4568,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<Map<String?, Object?>?> callFlutterEchoNullableMap(
       Map<String?, Object?>? aMap) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4597,7 +4597,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<ProxyApiTestEnum?> callFlutterEchoNullableEnum(
       ProxyApiTestEnum? anEnum) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4627,7 +4627,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 
   Future<ProxyApiSuperClass?> callFlutterEchoNullableProxyApi(
       ProxyApiSuperClass? aProxyApi) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4654,7 +4654,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<void> callFlutterNoopAsync() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4681,7 +4681,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 
   Future<String> callFlutterEchoAsyncString(String aString) async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiTestClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4766,14 +4766,14 @@ class ProxyApiTestClass extends ProxyApiSuperClass
 }
 
 /// ProxyApi to serve as a super class to the core ProxyApi interface.
-class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
+class ProxyApiSuperClass extends PigeonProxyApiBaseClass {
   ProxyApiSuperClass({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
   }) {
     final int __pigeon_instanceIdentifier =
         pigeon_instanceManager.addDartCreatedInstance(this);
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiSuperClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     () async {
@@ -4804,25 +4804,25 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
   /// Constructs [ProxyApiSuperClass] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
-  /// create copies for an [Pigeon_InstanceManager].
+  /// create copies for an [PigeonInstanceManager].
   @protected
   ProxyApiSuperClass.pigeon_detached({
     super.pigeon_binaryMessenger,
     super.pigeon_instanceManager,
   });
 
-  late final _Pigeon_ProxyApiBaseCodec __pigeon_codecProxyApiSuperClass =
-      _Pigeon_ProxyApiBaseCodec(pigeon_instanceManager);
+  late final _PigeonProxyApiBaseCodec __pigeon_codecProxyApiSuperClass =
+      _PigeonProxyApiBaseCodec(pigeon_instanceManager);
 
   static void pigeon_setUpMessageHandlers({
     bool pigeon_clearHandlers = false,
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
     ProxyApiSuperClass Function()? pigeon_newInstance,
   }) {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
     {
       final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
@@ -4841,7 +4841,7 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
           assert(arg_pigeon_instanceIdentifier != null,
               'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiSuperClass.pigeon_newInstance was null, expected non-null int.');
           try {
-            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+            (pigeon_instanceManager ?? PigeonInstanceManager.instance)
                 .addHostCreatedInstance(
               pigeon_newInstance?.call() ??
                   ProxyApiSuperClass.pigeon_detached(
@@ -4863,7 +4863,7 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
   }
 
   Future<void> aSuperMethod() async {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
         __pigeon_codecProxyApiSuperClass;
     final BinaryMessenger? __pigeon_binaryMessenger = pigeon_binaryMessenger;
     const String __pigeon_channelName =
@@ -4899,11 +4899,11 @@ class ProxyApiSuperClass extends Pigeon_ProxyApiBaseClass {
 }
 
 /// ProxyApi to serve as an interface to the core ProxyApi interface.
-class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
+class ProxyApiInterface extends PigeonProxyApiBaseClass {
   /// Constructs [ProxyApiInterface] without creating the associated native object.
   ///
   /// This should only be used by subclasses created by this library or to
-  /// create copies for an [Pigeon_InstanceManager].
+  /// create copies for an [PigeonInstanceManager].
   @protected
   ProxyApiInterface.pigeon_detached({
     super.pigeon_binaryMessenger,
@@ -4928,20 +4928,20 @@ class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
   /// );
   /// ```
   ///
-  /// Alternatively, [Pigeon_InstanceManager.removeWeakReference] can be used to
+  /// Alternatively, [PigeonInstanceManager.removeWeakReference] can be used to
   /// release the associated Native object manually.
   final void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod;
 
   static void pigeon_setUpMessageHandlers({
     bool pigeon_clearHandlers = false,
     BinaryMessenger? pigeon_binaryMessenger,
-    Pigeon_InstanceManager? pigeon_instanceManager,
+    PigeonInstanceManager? pigeon_instanceManager,
     ProxyApiInterface Function()? pigeon_newInstance,
     void Function(ProxyApiInterface pigeon_instance)? anInterfaceMethod,
   }) {
-    final _Pigeon_ProxyApiBaseCodec pigeonChannelCodec =
-        _Pigeon_ProxyApiBaseCodec(
-            pigeon_instanceManager ?? Pigeon_InstanceManager.instance);
+    final _PigeonProxyApiBaseCodec pigeonChannelCodec =
+        _PigeonProxyApiBaseCodec(
+            pigeon_instanceManager ?? PigeonInstanceManager.instance);
     final BinaryMessenger? binaryMessenger = pigeon_binaryMessenger;
     {
       final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
@@ -4960,7 +4960,7 @@ class ProxyApiInterface extends Pigeon_ProxyApiBaseClass {
           assert(arg_pigeon_instanceIdentifier != null,
               'Argument for dev.flutter.pigeon.pigeon_integration_tests.ProxyApiInterface.pigeon_newInstance was null, expected non-null int.');
           try {
-            (pigeon_instanceManager ?? Pigeon_InstanceManager.instance)
+            (pigeon_instanceManager ?? PigeonInstanceManager.instance)
                 .addHostCreatedInstance(
               pigeon_newInstance?.call() ??
                   ProxyApiInterface.pigeon_detached(
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart
index fc5ceba03dfb..aadce1b81d7b 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/test/instance_manager_test.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// This file specifically tests the test Pigeon_InstanceManager generated by core_tests.
+// This file specifically tests the test PigeonInstanceManager generated by core_tests.
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:shared_test_plugin_code/src/generated/proxy_api_tests.gen.dart';
@@ -10,8 +10,8 @@ import 'package:shared_test_plugin_code/src/generated/proxy_api_tests.gen.dart';
 void main() {
   group('InstanceManager', () {
     test('addHostCreatedInstance', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -27,8 +27,8 @@ void main() {
     });
 
     test('addHostCreatedInstance prevents already used objects and ids', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -51,8 +51,8 @@ void main() {
     });
 
     test('addFlutterCreatedInstance', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -70,8 +70,8 @@ void main() {
 
     test('removeWeakReference', () {
       int? weakInstanceId;
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (int instanceId) {
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (int instanceId) {
         weakInstanceId = instanceId;
       });
 
@@ -90,8 +90,8 @@ void main() {
     });
 
     test('removeWeakReference removes only weak reference', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -107,8 +107,8 @@ void main() {
     });
 
     test('removeStrongReference', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -121,8 +121,8 @@ void main() {
     });
 
     test('removeStrongReference removes only strong reference', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -137,8 +137,8 @@ void main() {
     });
 
     test('getInstance can add a new weak reference', () {
-      final Pigeon_InstanceManager instanceManager =
-          Pigeon_InstanceManager(onWeakReferenceRemoved: (_) {});
+      final PigeonInstanceManager instanceManager =
+          PigeonInstanceManager(onWeakReferenceRemoved: (_) {});
 
       final CopyableObject object = CopyableObject(
         pigeon_instanceManager: instanceManager,
@@ -156,7 +156,7 @@ void main() {
   });
 }
 
-class CopyableObject extends Pigeon_ProxyApiBaseClass {
+class CopyableObject extends PigeonProxyApiBaseClass {
   // ignore: non_constant_identifier_names
   CopyableObject({super.pigeon_instanceManager});
 
diff --git a/packages/pigeon/test/dart/proxy_api_test.dart b/packages/pigeon/test/dart/proxy_api_test.dart
index 081b3ab843bd..fb24a2038615 100644
--- a/packages/pigeon/test/dart/proxy_api_test.dart
+++ b/packages/pigeon/test/dart/proxy_api_test.dart
@@ -80,18 +80,18 @@ void main() {
       final String collapsedCode = _collapseNewlineAndIndentation(code);
 
       // Instance Manager
-      expect(code, contains(r'class Pigeon_InstanceManager'));
-      expect(code, contains(r'class _Pigeon_InstanceManagerApi'));
+      expect(code, contains(r'class PigeonInstanceManager'));
+      expect(code, contains(r'class _PigeonInstanceManagerApi'));
 
       // Base Api class
       expect(
         code,
-        contains(r'abstract class Pigeon_ProxyApiBaseClass'),
+        contains(r'abstract class PigeonProxyApiBaseClass'),
       );
 
       // Codec and class
-      expect(code, contains('class _Pigeon_ProxyApiBaseCodec'));
-      expect(code, contains(r'class Api extends Pigeon_ProxyApiBaseClass'));
+      expect(code, contains('class _PigeonProxyApiBaseCodec'));
+      expect(code, contains(r'class Api extends PigeonProxyApiBaseClass'));
 
       // Constructors
       expect(
@@ -202,7 +202,7 @@ void main() {
         expect(
           code,
           contains(
-            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2',
+            r'class Api extends PigeonProxyApiBaseClass implements Api2',
           ),
         );
       });
@@ -254,7 +254,7 @@ void main() {
         expect(
           code,
           contains(
-            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2, Api3',
+            r'class Api extends PigeonProxyApiBaseClass implements Api2, Api3',
           ),
         );
       });
@@ -309,7 +309,7 @@ void main() {
         expect(
           code,
           contains(
-            r'class Api extends Pigeon_ProxyApiBaseClass implements Api2',
+            r'class Api extends PigeonProxyApiBaseClass implements Api2',
           ),
         );
         expect(
@@ -839,7 +839,7 @@ void main() {
           collapsedCode,
           contains(
             r'static Future<void> doSomething({ BinaryMessenger? pigeon_binaryMessenger, '
-            r'Pigeon_InstanceManager? pigeon_instanceManager, })',
+            r'PigeonInstanceManager? pigeon_instanceManager, })',
           ),
         );
         expect(

From 1f0c6ce90159d5e851f5bea75eda868adec27dc9 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Tue, 27 Feb 2024 16:16:00 -0500
Subject: [PATCH 30/32] change to indexMap and fix extra space

---
 packages/pigeon/lib/dart/templates.dart       |  2 +-
 packages/pigeon/lib/dart_generator.dart       | 19 ++++++++++++-------
 .../src/generated/proxy_api_tests.gen.dart    |  2 +-
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/packages/pigeon/lib/dart/templates.dart b/packages/pigeon/lib/dart/templates.dart
index 6de2a11ee9a4..ce986b888dbf 100644
--- a/packages/pigeon/lib/dart/templates.dart
+++ b/packages/pigeon/lib/dart/templates.dart
@@ -237,7 +237,7 @@ String instanceManagerApiTemplate({
   return '''
 /// Generated API for managing the Dart and native `$instanceManagerClassName`s.
 class _$apiName {
-  /// Constructor for [_$apiName ].
+  /// Constructor for [_$apiName].
   _$apiName({BinaryMessenger? binaryMessenger})
       : _binaryMessenger = binaryMessenger;
 
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 9e59fecf4804..d69a70870ee3 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:code_builder/code_builder.dart' as cb;
-import 'package:collection/collection.dart' as collection;
 import 'package:dart_style/dart_style.dart';
 import 'package:path/path.dart' as path;
 
@@ -1075,7 +1074,8 @@ if (${_varNamePrefix}replyList == null) {
                       ..toThis = true
                       ..required = method.isRequired,
                   ),
-                ...constructor.parameters.mapIndexed(
+                ...indexMap(
+                  constructor.parameters,
                   (int index, NamedType parameter) => cb.Parameter(
                     (cb.ParameterBuilder builder) => builder
                       ..name = _getParameterName(index, parameter)
@@ -1296,7 +1296,8 @@ if (${_varNamePrefix}replyList == null) {
               ..isNullable = !method.isRequired
               ..requiredParameters.addAll(<cb.Reference>[
                 cb.refer('$apiName ${classMemberNamePrefix}instance'),
-                ...method.parameters.mapIndexed(
+                ...indexMap(
+                  method.parameters,
                   (int index, NamedType parameter) {
                     return cb.refer(
                       '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
@@ -1342,7 +1343,8 @@ if (${_varNamePrefix}replyList == null) {
                   cb.refer(
                     '${proxyApi.name} ${classMemberNamePrefix}instance',
                   ),
-                  ...method.parameters.mapIndexed(
+                  ...indexMap(
+                    method.parameters,
                     (int index, NamedType parameter) {
                       return cb.refer(
                         '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
@@ -1437,7 +1439,8 @@ if (${_varNamePrefix}replyList == null) {
                     ..returnType = cb.refer(apiName)
                     ..isNullable = true
                     ..requiredParameters.addAll(
-                      unattachedFields.mapIndexed(
+                      indexMap(
+                        unattachedFields,
                         (int index, ApiField field) {
                           return cb.refer(
                             '${_addGenericTypesNullable(field.type)} ${_getParameterName(index, field)}',
@@ -1460,7 +1463,8 @@ if (${_varNamePrefix}replyList == null) {
                     ..isNullable = true
                     ..requiredParameters.addAll(<cb.Reference>[
                       cb.refer('$apiName ${classMemberNamePrefix}instance'),
-                      ...method.parameters.mapIndexed(
+                      ...indexMap(
+                        method.parameters,
                         (int index, NamedType parameter) {
                           return cb.refer(
                             '${_addGenericTypesNullable(parameter.type)} ${_getParameterName(index, parameter)}',
@@ -1702,7 +1706,8 @@ if (${_varNamePrefix}replyList == null) {
           ))
           ..returns = _refer(method.returnType, asFuture: true)
           ..requiredParameters.addAll(
-            method.parameters.mapIndexed(
+            indexMap(
+              method.parameters,
               (int index, NamedType parameter) => cb.Parameter(
                 (cb.ParameterBuilder builder) => builder
                   ..name = _getParameterName(index, parameter)
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index 6aa044710aef..a14413a3d3fd 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -282,7 +282,7 @@ class PigeonInstanceManager {
 
 /// Generated API for managing the Dart and native `PigeonInstanceManager`s.
 class _PigeonInstanceManagerApi {
-  /// Constructor for [_PigeonInstanceManagerApi ].
+  /// Constructor for [_PigeonInstanceManagerApi].
   _PigeonInstanceManagerApi({BinaryMessenger? binaryMessenger})
       : _binaryMessenger = binaryMessenger;
 

From 7f1f70eb5db8d2e302e2cd0a97bff91312c71982 Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Tue, 27 Feb 2024 17:39:27 -0500
Subject: [PATCH 31/32] review comments and regen

---
 packages/pigeon/lib/ast.dart                  | 41 ++++++++
 packages/pigeon/lib/dart_generator.dart       | 97 ++++++-------------
 packages/pigeon/pigeons/proxy_api_tests.dart  |  8 +-
 .../src/generated/proxy_api_tests.gen.dart    | 60 ++++++------
 4 files changed, 105 insertions(+), 101 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 0c48faa45456..070ab5a5945f 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -4,6 +4,7 @@
 
 import 'package:collection/collection.dart' show ListEquality;
 import 'package:meta/meta.dart';
+import 'generator_tools.dart';
 import 'pigeon_lib.dart';
 
 typedef _ListEquals = bool Function(List<Object?>, List<Object?>);
@@ -177,6 +178,46 @@ class AstProxyApi extends Api {
         (ApiField field) => !field.isAttached,
       );
 
+  /// A list of AstProxyApis where each `extends` the API that follows it.
+  Iterable<AstProxyApi> get allSuperClasses => recursiveGetSuperClassApisChain(
+        this,
+      );
+
+  /// All ProxyApis this API `implements` and all the interfaces those APIs
+  /// `implements`.
+  Iterable<AstProxyApi> get apisOfInterfaces =>
+      recursiveFindAllInterfaceApis(this);
+
+  /// All methods inherited from interfaces and the interfaces of interfaces.
+  Iterable<Method> flutterMethodsFromInterfaces() sync* {
+    for (final AstProxyApi proxyApi in apisOfInterfaces) {
+      yield* proxyApi.methods;
+    }
+  }
+
+  /// A list of Flutter methods inherited from the ProxyApi that this ProxyApi
+  /// `extends`.
+  ///
+  /// This also recursively checks the ProxyApi that the super class `extends`
+  /// and so on.
+  ///
+  /// This also includes methods that super classes inherited from interfaces
+  /// with `implements`.
+  Iterable<Method> flutterMethodsFromSuperClasses() sync* {
+    for (final AstProxyApi proxyApi in allSuperClasses.toList().reversed) {
+      yield* proxyApi.flutterMethods;
+    }
+    if (superClass != null) {
+      final Set<AstProxyApi> interfaceApisFromSuperClasses =
+          recursiveFindAllInterfaceApis(
+        superClass!.associatedProxyApi!,
+      );
+      for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
+        yield* proxyApi.methods;
+      }
+    }
+  }
+
   @override
   String toString() {
     return '(ProxyApi name:$name methods:$methods field:$fields '
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index d69a70870ee3..3d07568a21c6 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -455,9 +455,9 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     Indent indent, {
     required String dartPackageName,
   }) {
-    indent.writeln(proxyApiBaseClass);
+    indent.format(proxyApiBaseClass);
 
-    indent.writeln(
+    indent.format(
       instanceManagerTemplate(
         allProxyApiNames: root.apis
             .whereType<AstProxyApi>()
@@ -473,7 +473,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     Indent indent, {
     required String dartPackageName,
   }) {
-    indent.writeln(
+    indent.format(
       instanceManagerApiTemplate(
         dartPackageName: dartPackageName,
         pigeonChannelCodecVarName: _pigeonChannelCodec,
@@ -487,7 +487,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
     Root root,
     Indent indent,
   ) {
-    indent.writeln(proxyApiBaseCodec);
+    indent.format(proxyApiBaseCodec);
   }
 
   @override
@@ -500,48 +500,11 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
   }) {
     const String codecName = '_${classNamePrefix}ProxyApiBaseCodec';
 
-    // Each api has a private codec instance used by every host method,
+    // Each API has a private codec instance used by every host method,
     // constructor, or non-static field.
     final String codecInstanceName = '${_varNamePrefix}codec${api.name}';
 
-    // A list of ProxyApis where each `extends` the API that follows it.
-    final List<AstProxyApi> superClassApisChain =
-        recursiveGetSuperClassApisChain(
-      api,
-    );
-
-    // All ProxyApis this API `implements` and all the interfaces those APIs
-    // `implements`.
-    final Set<AstProxyApi> apisOfInterfaces =
-        recursiveFindAllInterfaceApis(api);
-
-    // All methods inherited from interfaces and the interfaces of interfaces.
-    final List<Method> flutterMethodsFromInterfaces = <Method>[];
-    for (final AstProxyApi proxyApi in apisOfInterfaces) {
-      flutterMethodsFromInterfaces.addAll(proxyApi.methods);
-    }
-
-    // A list of Flutter methods inherited from the ProxyApi that this ProxyApi
-    // `extends`. This also recursively checks the ProxyApi that the super class
-    // `extends` and so on.
-    //
-    // This also includes methods that super classes inherited from interfaces
-    // with `implements`.
-    final List<Method> flutterMethodsFromSuperClasses = <Method>[];
-    for (final AstProxyApi proxyApi in superClassApisChain.reversed) {
-      flutterMethodsFromSuperClasses.addAll(proxyApi.flutterMethods);
-    }
-    if (api.superClass != null) {
-      final Set<AstProxyApi> interfaceApisFromSuperClasses =
-          recursiveFindAllInterfaceApis(
-        api.superClass!.associatedProxyApi!,
-      );
-      for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
-        flutterMethodsFromSuperClasses.addAll(proxyApi.methods);
-      }
-    }
-
-    // Ast class used by code_builder to generate the code.
+    // AST class used by code_builder to generate the code.
     final cb.Class proxyApi = cb.Class(
       (cb.ClassBuilder builder) => builder
         ..name = api.name
@@ -564,8 +527,8 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           codecInstanceName: codecInstanceName,
           superClassApi: api.superClass?.associatedProxyApi,
           unattachedFields: api.unattachedFields,
-          flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
-          flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+          flutterMethodsFromSuperClasses: api.flutterMethodsFromSuperClasses(),
+          flutterMethodsFromInterfaces: api.flutterMethodsFromInterfaces(),
           declaredFlutterMethods: api.flutterMethods,
         ))
         ..constructors.add(
@@ -573,8 +536,9 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
             apiName: api.name,
             superClassApi: api.superClass?.associatedProxyApi,
             unattachedFields: api.unattachedFields,
-            flutterMethodsFromSuperClasses: flutterMethodsFromSuperClasses,
-            flutterMethodsFromInterfaces: flutterMethodsFromInterfaces,
+            flutterMethodsFromSuperClasses:
+                api.flutterMethodsFromSuperClasses(),
+            flutterMethodsFromInterfaces: api.flutterMethodsFromInterfaces(),
             declaredFlutterMethods: api.flutterMethods,
           ),
         )
@@ -592,7 +556,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           api.flutterMethods,
           apiName: api.name,
         ))
-        ..fields.addAll(_proxyApiInterfaceApiFields(apisOfInterfaces))
+        ..fields.addAll(_proxyApiInterfaceApiFields(api.apisOfInterfaces))
         ..fields.addAll(_proxyApiAttachedFields(api.attachedFields))
         ..methods.add(
           _proxyApiSetUpMessageHandlerMethod(
@@ -602,8 +566,8 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
             codecName: codecName,
             unattachedFields: api.unattachedFields,
             hasCallbackConstructor: api.flutterMethods
-                .followedBy(flutterMethodsFromSuperClasses)
-                .followedBy(flutterMethodsFromInterfaces)
+                .followedBy(api.flutterMethodsFromSuperClasses())
+                .followedBy(api.flutterMethodsFromInterfaces())
                 .every((Method method) => !method.isRequired),
           ),
         )
@@ -623,17 +587,20 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           codecInstanceName: codecInstanceName,
           codecName: codecName,
         ))
-        ..methods.add(_proxyApiCopyMethod(
-          apiName: api.name,
-          unattachedFields: api.unattachedFields,
-          declaredAndInheritedFlutterMethods: flutterMethodsFromSuperClasses
-              .followedBy(flutterMethodsFromInterfaces)
-              .followedBy(api.flutterMethods),
-        )),
+        ..methods.add(
+          _proxyApiCopyMethod(
+            apiName: api.name,
+            unattachedFields: api.unattachedFields,
+            declaredAndInheritedFlutterMethods: api
+                .flutterMethodsFromSuperClasses()
+                .followedBy(api.flutterMethodsFromInterfaces())
+                .followedBy(api.flutterMethods),
+          ),
+        ),
     );
 
     final cb.DartEmitter emitter = cb.DartEmitter(useNullSafetySyntax: true);
-    indent.write(DartFormatter().format('${proxyApi.accept(emitter)}'));
+    indent.format(DartFormatter().format('${proxyApi.accept(emitter)}'));
   }
 
   /// Generates Dart source code for test support libraries based on the given AST
@@ -1140,8 +1107,8 @@ if (${_varNamePrefix}replyList == null) {
   /// The detached constructor present for every ProxyApi.
   ///
   /// This constructor doesn't include a host method call to create a new native
-  /// class instance. It is mainly used when the native side once to create a
-  /// Dart instance and when the `InstanceManager` wants to create a copy for
+  /// class instance. It is mainly used when the native side wants to create a
+  /// Dart instance or when the `InstanceManager` wants to create a copy for
   /// automatic garbage collection.
   cb.Constructor _proxyApiDetachedConstructor({
     required String apiName,
@@ -1260,17 +1227,13 @@ if (${_varNamePrefix}replyList == null) {
             <String>[
               ...method.documentationComments,
               ...<String>[
-                if (method.documentationComments.isNotEmpty)
-                  ''
-                else ...<String>[
-                  'Callback method.',
-                  '',
-                ],
+                if (method.documentationComments.isEmpty) 'Callback method.',
+                '',
                 'For the associated Native object to be automatically garbage collected,',
                 "it is required that the implementation of this `Function` doesn't have a",
                 'strong reference to the encapsulating class instance. When this `Function`',
                 'references a non-local variable, it is strongly recommended to access it',
-                'from a `WeakReference`:',
+                'with a `WeakReference`:',
                 '',
                 '```dart',
                 'final WeakReference weakMyVariable = WeakReference(myVariable);',
diff --git a/packages/pigeon/pigeons/proxy_api_tests.dart b/packages/pigeon/pigeons/proxy_api_tests.dart
index 1976af972d32..699e5dfaed86 100644
--- a/packages/pigeon/pigeons/proxy_api_tests.dart
+++ b/packages/pigeon/pigeons/proxy_api_tests.dart
@@ -10,8 +10,8 @@ enum ProxyApiTestEnum {
   three,
 }
 
-/// The core interface that each host language plugin must implement in
-/// platform_test integration tests.
+/// The core ProxyApi test class that each supported host language must
+/// implement in platform_tests integration tests.
 @ProxyApi()
 abstract class ProxyApiTestClass extends ProxyApiSuperClass
     implements ProxyApiInterface {
@@ -454,7 +454,7 @@ abstract class ProxyApiTestClass extends ProxyApiSuperClass
   String callFlutterEchoAsyncString(String aString);
 }
 
-/// ProxyApi to serve as a super class to the core ProxyApi interface.
+/// ProxyApi to serve as a super class to the core ProxyApi class.
 @ProxyApi()
 abstract class ProxyApiSuperClass {
   ProxyApiSuperClass();
@@ -462,7 +462,7 @@ abstract class ProxyApiSuperClass {
   void aSuperMethod();
 }
 
-/// ProxyApi to serve as an interface to the core ProxyApi interface.
+/// ProxyApi to serve as an interface to the core ProxyApi class.
 @ProxyApi()
 abstract class ProxyApiInterface {
   late void Function()? anInterfaceMethod;
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
index a14413a3d3fd..762f65d5aad0 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/proxy_api_tests.gen.dart
@@ -397,8 +397,8 @@ enum ProxyApiTestEnum {
   three,
 }
 
-/// The core interface that each host language plugin must implement in
-/// platform_test integration tests.
+/// The core ProxyApi test class that each supported host language must
+/// implement in platform_tests integration tests.
 class ProxyApiTestClass extends ProxyApiSuperClass
     implements ProxyApiInterface {
   ProxyApiTestClass({
@@ -635,7 +635,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -656,7 +656,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -677,7 +677,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -699,7 +699,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -723,7 +723,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -747,7 +747,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -771,7 +771,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -795,7 +795,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -819,7 +819,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -844,7 +844,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -868,7 +868,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -893,7 +893,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -917,7 +917,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -941,7 +941,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -965,7 +965,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -989,7 +989,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1013,7 +1013,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1037,7 +1037,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1061,7 +1061,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1085,7 +1085,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1109,7 +1109,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1133,7 +1133,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1157,7 +1157,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1182,7 +1182,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -1204,7 +1204,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);
@@ -4765,7 +4765,7 @@ class ProxyApiTestClass extends ProxyApiSuperClass
   }
 }
 
-/// ProxyApi to serve as a super class to the core ProxyApi interface.
+/// ProxyApi to serve as a super class to the core ProxyApi class.
 class ProxyApiSuperClass extends PigeonProxyApiBaseClass {
   ProxyApiSuperClass({
     super.pigeon_binaryMessenger,
@@ -4898,7 +4898,7 @@ class ProxyApiSuperClass extends PigeonProxyApiBaseClass {
   }
 }
 
-/// ProxyApi to serve as an interface to the core ProxyApi interface.
+/// ProxyApi to serve as an interface to the core ProxyApi class.
 class ProxyApiInterface extends PigeonProxyApiBaseClass {
   /// Constructs [ProxyApiInterface] without creating the associated native object.
   ///
@@ -4917,7 +4917,7 @@ class ProxyApiInterface extends PigeonProxyApiBaseClass {
   /// it is required that the implementation of this `Function` doesn't have a
   /// strong reference to the encapsulating class instance. When this `Function`
   /// references a non-local variable, it is strongly recommended to access it
-  /// from a `WeakReference`:
+  /// with a `WeakReference`:
   ///
   /// ```dart
   /// final WeakReference weakMyVariable = WeakReference(myVariable);

From 796d336a314659e7833f1bfee83f8076412d338b Mon Sep 17 00:00:00 2001
From: Maurice Parrish <10687576+bparrishMines@users.noreply.github.com>
Date: Wed, 28 Feb 2024 18:39:57 -0500
Subject: [PATCH 32/32] move methods

---
 packages/pigeon/lib/ast.dart                  | 106 ++++++++++++++++--
 packages/pigeon/lib/dart_generator.dart       |   7 +-
 packages/pigeon/lib/generator_tools.dart      |  86 --------------
 .../pigeon/test/generator_tools_test.dart     |  13 +--
 4 files changed, 101 insertions(+), 111 deletions(-)

diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 070ab5a5945f..bc4ec8c44777 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -4,7 +4,6 @@
 
 import 'package:collection/collection.dart' show ListEquality;
 import 'package:meta/meta.dart';
-import 'generator_tools.dart';
 import 'pigeon_lib.dart';
 
 typedef _ListEquals = bool Function(List<Object?>, List<Object?>);
@@ -179,18 +178,55 @@ class AstProxyApi extends Api {
       );
 
   /// A list of AstProxyApis where each `extends` the API that follows it.
-  Iterable<AstProxyApi> get allSuperClasses => recursiveGetSuperClassApisChain(
-        this,
+  ///
+  /// Returns an empty list if this api does not extend a ProxyApi.
+  ///
+  /// This method assumes the super classes of each ProxyApi doesn't create a
+  /// loop. Throws a [ArgumentError] if a loop is found.
+  ///
+  /// This method also assumes that all super classes are ProxyApis. Otherwise,
+  /// throws an [ArgumentError].
+  Iterable<AstProxyApi> allSuperClasses() {
+    final List<AstProxyApi> superClassChain = <AstProxyApi>[];
+
+    if (superClass != null && !superClass!.isProxyApi) {
+      throw ArgumentError(
+        'Could not find a ProxyApi for super class: ${superClass!.baseName}',
       );
+    }
+
+    AstProxyApi? currentProxyApi = superClass?.associatedProxyApi;
+    while (currentProxyApi != null) {
+      if (superClassChain.contains(currentProxyApi)) {
+        throw ArgumentError(
+          'Loop found when processing super classes for a ProxyApi: '
+          '$name, ${superClassChain.map((AstProxyApi api) => api.name)}',
+        );
+      }
+
+      superClassChain.add(currentProxyApi);
+
+      if (currentProxyApi.superClass != null &&
+          !currentProxyApi.superClass!.isProxyApi) {
+        throw ArgumentError(
+          'Could not find a ProxyApi for super class: '
+          '${currentProxyApi.superClass!.baseName}',
+        );
+      }
+
+      currentProxyApi = currentProxyApi.superClass?.associatedProxyApi;
+    }
+
+    return superClassChain;
+  }
 
   /// All ProxyApis this API `implements` and all the interfaces those APIs
   /// `implements`.
-  Iterable<AstProxyApi> get apisOfInterfaces =>
-      recursiveFindAllInterfaceApis(this);
+  Iterable<AstProxyApi> apisOfInterfaces() => _recursiveFindAllInterfaceApis();
 
   /// All methods inherited from interfaces and the interfaces of interfaces.
   Iterable<Method> flutterMethodsFromInterfaces() sync* {
-    for (final AstProxyApi proxyApi in apisOfInterfaces) {
+    for (final AstProxyApi proxyApi in apisOfInterfaces()) {
       yield* proxyApi.methods;
     }
   }
@@ -204,20 +240,70 @@ class AstProxyApi extends Api {
   /// This also includes methods that super classes inherited from interfaces
   /// with `implements`.
   Iterable<Method> flutterMethodsFromSuperClasses() sync* {
-    for (final AstProxyApi proxyApi in allSuperClasses.toList().reversed) {
+    for (final AstProxyApi proxyApi in allSuperClasses().toList().reversed) {
       yield* proxyApi.flutterMethods;
     }
     if (superClass != null) {
       final Set<AstProxyApi> interfaceApisFromSuperClasses =
-          recursiveFindAllInterfaceApis(
-        superClass!.associatedProxyApi!,
-      );
+          superClass!.associatedProxyApi!._recursiveFindAllInterfaceApis();
       for (final AstProxyApi proxyApi in interfaceApisFromSuperClasses) {
         yield* proxyApi.methods;
       }
     }
   }
 
+  /// Whether the api has a method that callbacks to Dart to add a new instance
+  /// to the InstanceManager.
+  ///
+  /// This is possible as long as no callback methods are required to
+  /// instantiate the class.
+  bool hasCallbackConstructor() {
+    return flutterMethods
+        .followedBy(flutterMethodsFromSuperClasses())
+        .followedBy(flutterMethodsFromInterfaces())
+        .every((Method method) => !method.isRequired);
+  }
+
+  // Recursively search for all the interfaces apis from a list of names of
+  // interfaces.
+  //
+  // This method assumes that all interfaces are ProxyApis and an api doesn't
+  // contains itself as an interface. Otherwise, throws an [ArgumentError].
+  Set<AstProxyApi> _recursiveFindAllInterfaceApis([
+    Set<AstProxyApi> seenApis = const <AstProxyApi>{},
+  ]) {
+    final Set<AstProxyApi> allInterfaces = <AstProxyApi>{};
+
+    allInterfaces.addAll(
+      interfaces.map(
+        (TypeDeclaration type) {
+          if (!type.isProxyApi) {
+            throw ArgumentError(
+              'Could not find a valid ProxyApi for an interface: $type',
+            );
+          } else if (seenApis.contains(type.associatedProxyApi)) {
+            throw ArgumentError(
+              'A ProxyApi cannot be a super class of itself: ${type.baseName}',
+            );
+          }
+          return type.associatedProxyApi!;
+        },
+      ),
+    );
+
+    // Adds the current api since it would be invalid for it to be an interface
+    // of itself.
+    final Set<AstProxyApi> newSeenApis = <AstProxyApi>{...seenApis, this};
+
+    for (final AstProxyApi interfaceApi in <AstProxyApi>{...allInterfaces}) {
+      allInterfaces.addAll(
+        interfaceApi._recursiveFindAllInterfaceApis(newSeenApis),
+      );
+    }
+
+    return allInterfaces;
+  }
+
   @override
   String toString() {
     return '(ProxyApi name:$name methods:$methods field:$fields '
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 3d07568a21c6..40ce7a6e5df4 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -556,7 +556,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
           api.flutterMethods,
           apiName: api.name,
         ))
-        ..fields.addAll(_proxyApiInterfaceApiFields(api.apisOfInterfaces))
+        ..fields.addAll(_proxyApiInterfaceApiFields(api.apisOfInterfaces()))
         ..fields.addAll(_proxyApiAttachedFields(api.attachedFields))
         ..methods.add(
           _proxyApiSetUpMessageHandlerMethod(
@@ -565,10 +565,7 @@ final BinaryMessenger? ${_varNamePrefix}binaryMessenger;
             dartPackageName: dartPackageName,
             codecName: codecName,
             unattachedFields: api.unattachedFields,
-            hasCallbackConstructor: api.flutterMethods
-                .followedBy(api.flutterMethodsFromSuperClasses())
-                .followedBy(api.flutterMethodsFromInterfaces())
-                .every((Method method) => !method.isRequired),
+            hasCallbackConstructor: api.hasCallbackConstructor(),
           ),
         )
         ..methods.addAll(
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index d2d17ebc40e7..66dd99750f34 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -645,92 +645,6 @@ String? deducePackageName(String mainDartFile) {
   }
 }
 
-/// Recursively search for all the interfaces apis from a list of names of
-/// interfaces.
-///
-/// This method assumes that all interfaces are ProxyApis and an api doesn't
-/// contains itself as an interface. Otherwise, throws an [ArgumentError].
-Set<AstProxyApi> recursiveFindAllInterfaceApis(
-  AstProxyApi api, {
-  Set<AstProxyApi> seenApis = const <AstProxyApi>{},
-}) {
-  final Set<AstProxyApi> allInterfaces = <AstProxyApi>{};
-
-  allInterfaces.addAll(
-    api.interfaces.map(
-      (TypeDeclaration type) {
-        if (!type.isProxyApi) {
-          throw ArgumentError(
-            'Could not find a valid ProxyApi for an interface: $type',
-          );
-        } else if (seenApis.contains(type.associatedProxyApi)) {
-          throw ArgumentError(
-            'A ProxyApi cannot be a super class of itself: ${type.baseName}',
-          );
-        }
-        return type.associatedProxyApi!;
-      },
-    ),
-  );
-
-  // Adds the current api since it would be invalid for it to be an interface
-  // of itself.
-  final Set<AstProxyApi> newSeenApis = <AstProxyApi>{...seenApis, api};
-
-  for (final AstProxyApi interfaceApi in <AstProxyApi>{...allInterfaces}) {
-    allInterfaces.addAll(recursiveFindAllInterfaceApis(
-      interfaceApi,
-      seenApis: newSeenApis,
-    ));
-  }
-
-  return allInterfaces;
-}
-
-/// Creates a list of ProxyApis where each `extends` the ProxyApi that follows
-/// it.
-///
-/// Returns an empty list if [proxyApi] does not extend a ProxyApi.
-///
-/// This method assumes the super classes of each ProxyApi doesn't create a
-/// loop. Throws a [ArgumentError] if a loop is found.
-///
-/// This method also assumes that all super classes are ProxyApis. Otherwise,
-/// throws an [ArgumentError].
-List<AstProxyApi> recursiveGetSuperClassApisChain(AstProxyApi api) {
-  final List<AstProxyApi> superClassChain = <AstProxyApi>[];
-
-  if (api.superClass != null && !api.superClass!.isProxyApi) {
-    throw ArgumentError(
-      'Could not find a ProxyApi for super class: ${api.superClass!.baseName}',
-    );
-  }
-
-  AstProxyApi? currentProxyApi = api.superClass?.associatedProxyApi;
-  while (currentProxyApi != null) {
-    if (superClassChain.contains(currentProxyApi)) {
-      throw ArgumentError(
-        'Loop found when processing super classes for a ProxyApi: '
-        '${api.name}, ${superClassChain.map((AstProxyApi api) => api.name)}',
-      );
-    }
-
-    superClassChain.add(currentProxyApi);
-
-    if (currentProxyApi.superClass != null &&
-        !currentProxyApi.superClass!.isProxyApi) {
-      throw ArgumentError(
-        'Could not find a ProxyApi for super class: '
-        '${currentProxyApi.superClass!.baseName}',
-      );
-    }
-
-    currentProxyApi = currentProxyApi.superClass?.associatedProxyApi;
-  }
-
-  return superClassChain;
-}
-
 /// Enum to specify api type when generating code.
 enum ApiType {
   /// Flutter api.
diff --git a/packages/pigeon/test/generator_tools_test.dart b/packages/pigeon/test/generator_tools_test.dart
index 6b43b93eecc5..e68bb96239c1 100644
--- a/packages/pigeon/test/generator_tools_test.dart
+++ b/packages/pigeon/test/generator_tools_test.dart
@@ -404,10 +404,8 @@ void main() {
       ),
     );
 
-    final List<AstProxyApi> apiChain = recursiveGetSuperClassApisChain(api);
-
     expect(
-      apiChain,
+      api.allSuperClasses().toList(),
       containsAllInOrder(<AstProxyApi>[
         superClassApi,
         superClassOfSuperClassApi,
@@ -478,10 +476,8 @@ void main() {
       },
     );
 
-    final Set<AstProxyApi> allInterfaces = recursiveFindAllInterfaceApis(api);
-
     expect(
-      allInterfaces,
+      api.apisOfInterfaces(),
       containsAll(<AstProxyApi>[
         interfaceApi,
         interfaceApi2,
@@ -523,9 +519,6 @@ void main() {
       TypeDeclaration(baseName: 'A', isNullable: false, associatedProxyApi: a),
     };
 
-    expect(
-      () => recursiveFindAllInterfaceApis(a),
-      throwsArgumentError,
-    );
+    expect(() => a.apisOfInterfaces(), throwsArgumentError);
   });
 }