Extension type. Check getter/setter types correspondence.

Change-Id: Idcf1313f0119145fce23b2617ad03b4d852b54d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/330663
Reviewed-by: Phil Quitslund <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/error/getter_setter_types_verifier.dart

@@ -39,6 +39,11 @@ class GetterSetterTypesVerifier {
     }
   }
 
+  void checkExtensionType(ExtensionTypeElement element, Interface interface) {
+    checkInterface(element, interface);
+    checkStaticAccessors(element.accessors);
+  }
+
   void checkInterface(InterfaceElement element, Interface interface) {
     var libraryUri = element.library.source.uri;
 
@@ -54,7 +59,12 @@ class GetterSetterTypesVerifier {
           if (!_match(getterType, setterType)) {
             Element errorElement;
             if (getter.enclosingElement == element) {
-              errorElement = getter;
+              if (element is ExtensionTypeElement &&
+                  element.representation.getter == getter) {
+                errorElement = setter;
+              } else {
+                errorElement = getter;
+              }
             } else if (setter.enclosingElement == element) {
               errorElement = setter;
             } else {

pkg/analyzer/lib/src/generated/error_verifier.dart

@@ -721,6 +721,12 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
       _checkForExtensionTypeWithAbstractMember(node);
       _checkForWrongTypeParameterVarianceInSuperinterfaces();
 
+      final interface = _inheritanceManager.getInterface(element);
+      GetterSetterTypesVerifier(
+        typeSystem: typeSystem,
+        errorReporter: errorReporter,
+      ).checkExtensionType(element, interface);
+
       super.visitExtensionTypeDeclaration(node);
     } finally {
       _constructorFieldsVerifier.leaveClass();

pkg/analyzer/test/src/diagnostics/getter_not_subtype_setter_types_test.dart

@@ -370,6 +370,63 @@ extension E on Object {
     ]);
   }
 
+  test_extensionType_instance() async {
+    await assertErrorsInCode('''
+extension type A(int it) {
+  int get foo => 0;
+  void set foo(String _) {}
+}
+''', [
+      error(CompileTimeErrorCode.GETTER_NOT_SUBTYPE_SETTER_TYPES, 37, 3),
+    ]);
+  }
+
+  test_extensionType_instance_fromImplements() async {
+    await assertErrorsInCode('''
+extension type A(int it) {
+  void set foo(String _) {}
+}
+
+extension type B(int it) implements A {
+  int get foo => 0;
+}
+''', [
+      error(CompileTimeErrorCode.GETTER_NOT_SUBTYPE_SETTER_TYPES, 108, 3),
+    ]);
+  }
+
+  test_extensionType_instance_representationField() async {
+    await assertErrorsInCode('''
+extension type A(int it) {
+  void set it(String _) {}
+}
+''', [
+      error(CompileTimeErrorCode.GETTER_NOT_SUBTYPE_SETTER_TYPES, 38, 2),
+    ]);
+  }
+
+  test_extensionType_static() async {
+    await assertErrorsInCode('''
+extension type A(int it) {
+  static int get foo => 0;
+  static set foo(String v) {}
+}
+''', [
+      error(CompileTimeErrorCode.GETTER_NOT_SUBTYPE_SETTER_TYPES, 44, 3),
+    ]);
+  }
+
+  test_extensionType_static_field() async {
+    await assertErrorsInCode('''
+extension type A(int it) {
+  static final int foo = 0;
+  static set foo(String v) {}
+}
+''', [
+      error(CompileTimeErrorCode.GETTER_NOT_SUBTYPE_SETTER_TYPES, 46, 3),
+    ]);
+  }
+
   test_topLevel() async {
     await assertErrorsInCode('''
 int get foo => 0;