[pigeon] Allows kotlin generator to skip error class generation

packages/pigeon/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 17.0.1
 
+* [kotlin] Adds `includeErrorClass` to `KotlinOptions`.
 * Updates minimum supported SDK version to Flutter 3.13/Dart 3.1.
 
 ## 17.0.0

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 = '17.0.0';
+const String pigeonVersion = '17.0.1';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/kotlin_generator.dart

@@ -32,6 +32,7 @@ class KotlinOptions {
     this.package,
     this.copyrightHeader,
     this.errorClassName,
+    this.includeErrorClass = true,
   });
 
   /// The package where the generated class will live.
@@ -43,13 +44,20 @@ class KotlinOptions {
   /// The name of the error class used for passing custom error parameters.
   final String? errorClassName;
 
+  /// Whether to include the error class in generation.
+  ///
+  /// This should only ever be set to false if you have another generated
+  /// Kotlin file in the same directory.
+  final bool includeErrorClass;
+
   /// Creates a [KotlinOptions] from a Map representation where:
   /// `x = KotlinOptions.fromMap(x.toMap())`.
   static KotlinOptions fromMap(Map<String, Object> map) {
     return KotlinOptions(
       package: map['package'] as String?,
       copyrightHeader: map['copyrightHeader'] as Iterable<String>?,
       errorClassName: map['errorClassName'] as String?,
+      includeErrorClass: map['includeErrorClass'] as bool? ?? true,
     );
   }
 
@@ -60,6 +68,7 @@ class KotlinOptions {
       if (package != null) 'package': package!,
       if (copyrightHeader != null) 'copyrightHeader': copyrightHeader!,
       if (errorClassName != null) 'errorClassName': errorClassName!,
+      'includeErrorClass': includeErrorClass,
     };
     return result;
   }
@@ -298,7 +307,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     addDocumentationComments(
         indent, field.documentationComments, _docCommentSpec);
     indent.write(
-        'val ${field.name}: ${_nullsafeKotlinTypeForDartType(field.type)}');
+        'val ${field.name}: ${_nullSafeKotlinTypeForDartType(field.type)}');
     final String defaultNil = field.type.isNullable ? ' = null' : '';
     indent.add(defaultNil);
   }
@@ -361,16 +370,15 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
         });
       });
 
-      final String errorClassName = _getErrorClassName(generatorOptions);
       for (final Method method in api.methods) {
         _writeFlutterMethod(
           indent,
+          generatorOptions: generatorOptions,
           name: method.name,
           parameters: method.parameters,
           returnType: method.returnType,
           channelName: makeChannelName(api, method, dartPackageName),
           documentationComments: method.documentationComments,
-          errorClassName: errorClassName,
           dartPackageName: dartPackageName,
         );
       }
@@ -588,7 +596,9 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     if (hasFlutterApi) {
       _writeCreateConnectionError(generatorOptions, indent);
     }
-    _writeErrorClass(generatorOptions, indent);
+    if (generatorOptions.includeErrorClass) {
+      _writeErrorClass(generatorOptions, indent);
+    }
   }
 
   static void _writeMethodDeclaration(
@@ -606,7 +616,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     final List<String> argSignature = <String>[];
     if (parameters.isNotEmpty) {
       final Iterable<String> argTypes = parameters
-          .map((NamedType e) => _nullsafeKotlinTypeForDartType(e.type));
+          .map((NamedType e) => _nullSafeKotlinTypeForDartType(e.type));
       final Iterable<String> argNames = indexMap(parameters, getArgumentName);
       argSignature.addAll(
         map2(
@@ -620,7 +630,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
     }
 
     final String returnTypeString =
-        returnType.isVoid ? '' : _nullsafeKotlinTypeForDartType(returnType);
+        returnType.isVoid ? '' : _nullSafeKotlinTypeForDartType(returnType);
 
     final String resultType = returnType.isVoid ? 'Unit' : returnTypeString;
     addDocumentationComments(indent, documentationComments, _docCommentSpec);
@@ -700,7 +710,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
             indent.write('$call ');
             final String resultType = returnType.isVoid
                 ? 'Unit'
-                : _nullsafeKotlinTypeForDartType(returnType);
+                : _nullSafeKotlinTypeForDartType(returnType);
             indent.addScoped('{ result: Result<$resultType> ->', '}', () {
               indent.writeln('val error = result.exceptionOrNull()');
               indent.writeScoped('if (error != null) {', '}', () {
@@ -751,11 +761,11 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
 
   void _writeFlutterMethod(
     Indent indent, {
+    required KotlinOptions generatorOptions,
     required String name,
     required List<Parameter> parameters,
     required TypeDeclaration returnType,
     required String channelName,
-    required String errorClassName,
     required String dartPackageName,
     List<String> documentationComments = const <String>[],
     int? minApiRequirement,
@@ -778,6 +788,7 @@ class KotlinGenerator extends StructuredGenerator<KotlinOptions> {
       getArgumentName: _getSafeArgumentName,
     );
 
+    final String errorClassName = _getErrorClassName(generatorOptions);
     indent.addScoped('{', '}', () {
       onWriteBody(
         indent,
@@ -910,9 +921,9 @@ String _kotlinTypeForBuiltinGenericDartType(TypeDeclaration type) {
   } else {
     switch (type.baseName) {
       case 'List':
-        return 'List<${_nullsafeKotlinTypeForDartType(type.typeArguments.first)}>';
+        return 'List<${_nullSafeKotlinTypeForDartType(type.typeArguments.first)}>';
       case 'Map':
-        return 'Map<${_nullsafeKotlinTypeForDartType(type.typeArguments.first)}, ${_nullsafeKotlinTypeForDartType(type.typeArguments.last)}>';
+        return 'Map<${_nullSafeKotlinTypeForDartType(type.typeArguments.first)}, ${_nullSafeKotlinTypeForDartType(type.typeArguments.last)}>';
       default:
         return '${type.baseName}<${_flattenTypeArguments(type.typeArguments)}>';
     }
@@ -946,7 +957,7 @@ String _kotlinTypeForDartType(TypeDeclaration type) {
   return _kotlinTypeForBuiltinDartType(type) ?? type.baseName;
 }
 
-String _nullsafeKotlinTypeForDartType(TypeDeclaration type) {
+String _nullSafeKotlinTypeForDartType(TypeDeclaration type) {
   final String nullSafe = type.isNullable ? '?' : '';
   return '${_kotlinTypeForDartType(type)}$nullSafe';
 }
@@ -969,7 +980,7 @@ String _cast(Indent indent, String variable, {required TypeDeclaration type}) {
     }
     return '${type.baseName}.ofRaw($variable as Int)!!';
   }
-  return '$variable as ${_nullsafeKotlinTypeForDartType(type)}';
+  return '$variable as ${_nullSafeKotlinTypeForDartType(type)}';
 }
 
 String _castInt(bool isNullable) {

packages/pigeon/lib/pigeon_lib.dart

@@ -776,6 +776,7 @@ class KotlinGeneratorAdapter implements GeneratorAdapter {
         options.kotlinOptions ?? const KotlinOptions();
     kotlinOptions = kotlinOptions.merge(KotlinOptions(
       errorClassName: kotlinOptions.errorClassName ?? 'FlutterError',
+      includeErrorClass: kotlinOptions.includeErrorClass,
       copyrightHeader: options.copyrightHeader != null
           ? _lineReader(
               path.posix.join(options.basePath ?? '', options.copyrightHeader))