@JsonCodable() supports super toJson and fromJson.

goldens/foo/lib/foo.analyzer.json

@@ -7,6 +7,7 @@
             "bar": {
               "properties": {
                 "isAbstract": false,
+                "isConstructor": false,
                 "isGetter": false,
                 "isField": true,
                 "isMethod": false,
@@ -22,6 +23,19 @@
                   "instantiation": []
                 }
               }
+            },
+            "": {
+              "properties": {
+                "isAbstract": false,
+                "isConstructor": true,
+                "isGetter": false,
+                "isField": false,
+                "isMethod": false,
+                "isStatic": false
+              },
+              "requiredPositionalParameters": [],
+              "optionalPositionalParameters": [],
+              "namedParameters": []
             }
           }
         },
@@ -30,6 +44,7 @@
             "bar": {
               "properties": {
                 "isAbstract": false,
+                "isConstructor": false,
                 "isGetter": false,
                 "isField": true,
                 "isMethod": false,
@@ -45,6 +60,19 @@
                   "instantiation": []
                 }
               }
+            },
+            "": {
+              "properties": {
+                "isAbstract": false,
+                "isConstructor": true,
+                "isGetter": false,
+                "isField": false,
+                "isMethod": false,
+                "isStatic": false
+              },
+              "requiredPositionalParameters": [],
+              "optionalPositionalParameters": [],
+              "namedParameters": []
             }
           }
         }

goldens/foo/lib/json_codable_test.analyzer.augmentations

@@ -94,6 +94,23 @@ json[r'x'] = x;
   return json;
 }
 
+}
+augment class D {
+// TODO(davidmorgan): see https://github.com/dart-lang/macros/issues/80.
+// external D.fromJson(prefix0.Map<prefix0.String, prefix0.Object?> json);
+// external prefix0.Map<prefix0.String, prefix0.Object?> toJson();
+
+augment D.fromJson(prefix0.Map<prefix0.String, prefix0.Object?> json) :
+y = json[r'y'] as prefix0.String,
+super.fromJson(json);
+
+augment prefix0.Map<prefix0.String, prefix0.Object?> toJson() {
+  final json = super.toJson();
+json[r'y'] = y;
+
+  return json;
+}
+
 }
 augment class E {
 // TODO(davidmorgan): see https://github.com/dart-lang/macros/issues/80.

goldens/foo/lib/json_codable_test.dart

@@ -106,7 +106,6 @@ void main() {
       expect(b.toJson(), isEmpty);
     });
 
-    /* TODO(davidmorgan): make this test work.
     test('class hierarchies', () {
       var json = {
         'x': 1,
@@ -118,7 +117,6 @@ void main() {
 
       expect(d.toJson(), equals(json));
     });
-    */
 
     test('collections of nullable objects', () {
       var json = {
@@ -266,7 +264,6 @@ class C {
   final int x;
 }
 
-/*
 @JsonCodable()
 class D extends C {
   // TODO(davidmorgan): see https://github.com/dart-lang/macros/issues/80.
@@ -275,7 +272,6 @@ class D extends C {
 
   final String y;
 }
-*/
 
 @JsonCodable()
 class E {
@@ -310,3 +306,17 @@ class F {
 
   final int fieldWithDollarSign$;
 }
+
+
+
+
+
+
+
+
+
+
+
+
+
+

pkgs/_analyzer_macros/lib/query_service.dart

@@ -40,13 +40,49 @@ class AnalyzerQueryService implements QueryService {
       interface.members[field.name] = Member(
           properties: Properties(
             isAbstract: field.isAbstract,
+            isConstructor: false,
             isGetter: false,
             isField: true,
             isMethod: false,
             isStatic: field.isStatic,
           ),
           returnType: types.addDartType(field.type));
     }
+    for (final constructor in clazz.constructors) {
+      interface.members[constructor.name] = Member(
+          requiredPositionalParameters: constructor
+              .requiredPositionalParameters(types.translator, types.context),
+          optionalPositionalParameters: constructor
+              .optionalPositionalParameters(types.translator, types.context),
+          namedParameters:
+              constructor.namedParameters(types.translator, types.context),
+          properties: Properties(
+            isAbstract: constructor.isAbstract,
+            isConstructor: true,
+            isGetter: false,
+            isField: false,
+            isMethod: false,
+            isStatic: false,
+          ));
+    }
+    for (final method in clazz.methods) {
+      interface.members[method.name] = Member(
+          requiredPositionalParameters: method.requiredPositionalParameters(
+              types.translator, types.context),
+          optionalPositionalParameters: method.optionalPositionalParameters(
+              types.translator, types.context),
+          namedParameters:
+              method.namedParameters(types.translator, types.context),
+          properties: Properties(
+            isAbstract: method.isAbstract,
+            isConstructor: false,
+            isGetter: false,
+            isField: false,
+            isMethod: true,
+            isStatic: method.isStatic,
+          ),
+          returnType: types.addDartType(method.returnType));
+    }
     return Model(types: types.typeHierarchy)
       ..uris[uri] = (Library()..scopes[clazz.name] = interface);
   }
@@ -105,3 +141,30 @@ class AnalyzerTypeHierarchy {
     );
   }
 }
+
+extension ExecutableElementExtension on ExecutableElement {
+  List<StaticTypeDesc> requiredPositionalParameters(
+      AnalyzerTypesToMacros translator, TypeTranslationContext context) {
+    return parameters
+        .where((p) => p.isRequiredPositional)
+        .map((p) => p.type.acceptWithArgument(translator, context))
+        .toList();
+  }
+
+  List<StaticTypeDesc> optionalPositionalParameters(
+      AnalyzerTypesToMacros translator, TypeTranslationContext context) {
+    return parameters
+        .where((p) => p.isRequiredPositional)
+        .map((p) => p.type.acceptWithArgument(translator, context))
+        .toList();
+  }
+
+  List<NamedFunctionTypeParameter> namedParameters(
+      AnalyzerTypesToMacros translator, TypeTranslationContext context) {
+    return parameters
+        .where((p) => p.isNamed)
+        .map((p) => p.type.acceptWithArgument(translator, context))
+        .cast<NamedFunctionTypeParameter>()
+        .toList();
+  }
+}

pkgs/_test_macros/lib/json_codable.dart

@@ -50,6 +50,48 @@ class JsonCodableImplementation implements Macro {
     final model = await host.query(Query(target: target));
     final clazz = model.uris[target.uri]!.scopes[target.name]!;
     // TODO(davidmorgan): check for super `fromJson`.
+
+    MacroScope.current.addModel(model);
+    final superclassName =
+        MacroScope.current.typeSystem.lookupSupertype(target);
+    var superclassHasFromJson = false;
+    if (superclassName.asString != 'dart:core#Object') {
+      final supermodel = await host.query(Query(target: superclassName));
+      final superclass =
+          supermodel.uris[superclassName.uri]!.scopes[superclassName.name]!;
+      final constructor = superclass.members['fromJson'];
+      final memberIsValid = constructor != null &&
+          constructor.properties.isConstructor &&
+          constructor.requiredPositionalParameters.length == 1 &&
+          constructor.requiredPositionalParameters[0].type ==
+              StaticTypeDescType.namedTypeDesc &&
+          constructor.requiredPositionalParameters[0].asNamedTypeDesc.name
+                  .asString ==
+              'dart:core#Map' &&
+          constructor.requiredPositionalParameters[0].asNamedTypeDesc
+                  .instantiation[0].asNamedTypeDesc.name.asString ==
+              'dart:core#String' &&
+          constructor
+                  .requiredPositionalParameters[0]
+                  .asNamedTypeDesc
+                  .instantiation[1]
+                  .asNullableTypeDesc
+                  .inner
+                  .asNamedTypeDesc
+                  .name
+                  .asString ==
+              'dart:core#Object';
+      if (memberIsValid) {
+        superclassHasFromJson = true;
+      } else {
+        // TODO(davidmorgan): report as a diagnostic.
+        throw ArgumentError(
+            'Serialization of classes that extend other classes is only '
+            'supported if those classes have a valid '
+            '`fromJson(Map<String, Object?> json)` constructor.');
+      }
+    }
+
     final initializers = <String>[];
     for (final field
         in clazz.members.entries.where((m) => m.value.properties.isField)) {
@@ -59,13 +101,42 @@ class JsonCodableImplementation implements Macro {
           .add('$name = ${_convertTypeFromJson("json[r'$name']", type)}');
     }
 
+    if (superclassHasFromJson) {
+      initializers.add('super.fromJson(json)');
+    }
+
     // TODO(davidmorgan): helper for augmenting initializers.
     // See: https://github.com/dart-lang/sdk/blob/main/pkg/_macros/lib/src/executor/builder_impls.dart#L500
     result.add(Augmentation(code: '''
 augment ${target.name}.fromJson($_jsonMapType json) :
 ${initializers.join(',\n')};
 '''));
 
+    var superclassHasToJson = false;
+    if (superclassName.asString != 'dart:core#Object') {
+      final supermodel = await host.query(Query(target: superclassName));
+      final superclass =
+          supermodel.uris[superclassName.uri]!.scopes[superclassName.name]!;
+      final method = superclass.members['toJson'];
+      final memberIsValid = method != null &&
+          method.properties.isMethod &&
+          !method.properties.isStatic &&
+          method.requiredPositionalParameters.isEmpty &&
+          method.optionalPositionalParameters.isEmpty &&
+          method.namedParameters.isEmpty &&
+          // TODO(davidmorgan): remainder of type check.
+          method.returnType.asNamedTypeDesc.name.asString == 'dart:core#Map';
+      if (memberIsValid) {
+        superclassHasToJson = true;
+      } else {
+        // TODO(davidmorgan): report as a diagnostic.
+        throw ArgumentError(
+            'Serialization of classes that extend other classes is only '
+            'supported if those classes have a valid '
+            '`Map<String, Object?> json toJson()` method.');
+      }
+    }
+
     final serializers = <String>[];
     for (final field
         in clazz.members.entries.where((m) => m.value.properties.isField)) {
@@ -80,9 +151,11 @@ ${initializers.join(',\n')};
 
     // TODO(davidmorgan): helper for augmenting methods.
     // See: https://github.com/dart-lang/sdk/blob/main/pkg/_macros/lib/src/executor/builder_impls.dart#L500
+    final jsonInitializer =
+        superclassHasToJson ? 'super.toJson()' : '$_jsonMapTypeForLiteral{}';
     result.add(Augmentation(code: '''
 augment $_jsonMapType toJson() {
-  final json = $_jsonMapTypeForLiteral{};
+  final json = $jsonInitializer;
 ${serializers.join('')}
   return json;
 }

pkgs/dart_model/lib/src/dart_model.g.dart

@@ -138,21 +138,48 @@ extension type Member.fromJson(Map<String, Object?> node) implements Object {
   static final TypedMapSchema _schema = TypedMapSchema({
     'properties': Type.typedMapPointer,
     'returnType': Type.typedMapPointer,
+    'requiredPositionalParameters': Type.closedListPointer,
+    'optionalPositionalParameters': Type.closedListPointer,
+    'namedParameters': Type.closedListPointer,
+    'parameters': Type.typedMapPointer,
   });
   Member({
     Properties? properties,
     StaticTypeDesc? returnType,
+    List<StaticTypeDesc>? requiredPositionalParameters,
+    List<StaticTypeDesc>? optionalPositionalParameters,
+    List<NamedFunctionTypeParameter>? namedParameters,
+    Properties? parameters,
   }) : this.fromJson(Scope.createMap(
           _schema,
           properties,
           returnType,
+          requiredPositionalParameters,
+          optionalPositionalParameters,
+          namedParameters,
+          parameters,
         ));
 
   /// The properties of this member.
   Properties get properties => node['properties'] as Properties;
 
   /// The return type of this member, if it has one.
   StaticTypeDesc get returnType => node['returnType'] as StaticTypeDesc;
+
+  /// The required positional parameters of this member, if it has them.
+  List<StaticTypeDesc> get requiredPositionalParameters =>
+      (node['requiredPositionalParameters'] as List).cast();
+
+  /// The optional positional parameters of this member, if it has them.
+  List<StaticTypeDesc> get optionalPositionalParameters =>
+      (node['optionalPositionalParameters'] as List).cast();
+
+  /// The named positional parameters of this member, if it has them.
+  List<NamedFunctionTypeParameter> get namedParameters =>
+      (node['namedParameters'] as List).cast();
+
+  /// The properties of this member.
+  Properties get parameters => node['parameters'] as Properties;
 }
 
 /// Partial model of a corpus of Dart source code.
@@ -266,6 +293,7 @@ extension type Properties.fromJson(Map<String, Object?> node)
   static final TypedMapSchema _schema = TypedMapSchema({
     'isAbstract': Type.boolean,
     'isClass': Type.boolean,
+    'isConstructor': Type.boolean,
     'isGetter': Type.boolean,
     'isField': Type.boolean,
     'isMethod': Type.boolean,
@@ -274,6 +302,7 @@ extension type Properties.fromJson(Map<String, Object?> node)
   Properties({
     bool? isAbstract,
     bool? isClass,
+    bool? isConstructor,
     bool? isGetter,
     bool? isField,
     bool? isMethod,
@@ -282,6 +311,7 @@ extension type Properties.fromJson(Map<String, Object?> node)
           _schema,
           isAbstract,
           isClass,
+          isConstructor,
           isGetter,
           isField,
           isMethod,
@@ -294,6 +324,9 @@ extension type Properties.fromJson(Map<String, Object?> node)
   /// Whether the entity is a class.
   bool get isClass => node['isClass'] as bool;
 
+  /// Whether the entity is a constructor.
+  bool get isConstructor => node['isConstructor'] as bool;
+
   /// Whether the entity is a getter.
   bool get isGetter => node['isGetter'] as bool;