@visibleForTesting validation for extension type members

See: #53434

Change-Id: I0cca5b38fc6e432a8eb5e1ab3381625203063cab
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/326180
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: pq

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

@@ -414,8 +414,8 @@ class AnnotationVerifier {
       } else if (parent.declaredElement != null) {
         final declaredElement = parent.declaredElement!;
         if (element.isVisibleForOverriding &&
-                !declaredElement.isInstanceMember ||
-            declaredElement.enclosingElement is ExtensionTypeElement) {
+            (!declaredElement.isInstanceMember ||
+                declaredElement.enclosingElement is ExtensionTypeElement)) {
           reportInvalidVisibleForOverriding();
         }
 

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

@@ -285,6 +285,46 @@ class B {
     ]);
   }
 
+  test_methodInExtensionType() async {
+    newFile('$testPackageRootPath/lib1.dart', r'''
+import 'package:meta/meta.dart';
+extension type E(int i) {
+  @visibleForTesting
+  int m() => 1;
+}
+''');
+    newFile('$testPackageRootPath/lib2.dart', r'''
+import 'lib1.dart';
+void main() {
+  E(1).m();
+}
+''');
+
+    await _resolveFile('$testPackageRootPath/lib1.dart');
+    await _resolveFile('$testPackageRootPath/lib2.dart', [
+      error(WarningCode.INVALID_USE_OF_VISIBLE_FOR_TESTING_MEMBER, 41, 1),
+    ]);
+  }
+
+  test_methodInExtensionType_fromTestDirectory() async {
+    newFile('$testPackageRootPath/lib1.dart', r'''
+import 'package:meta/meta.dart';
+extension type E(int i) {
+  @visibleForTesting
+  int m() => 1;
+}
+''');
+    newFile('$testPackageRootPath/test/test.dart', r'''
+import 'lib1.dart';
+void main() {
+  E(1).m();
+}
+''');
+
+    await _resolveFile('$testPackageRootPath/lib1.dart');
+    await _resolveFile('$testPackageRootPath/lib2.dart');
+  }
+
   test_mixin() async {
     newFile('$testPackageRootPath/lib1.dart', r'''
 import 'package:meta/meta.dart';

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

@@ -87,6 +87,16 @@ void f(_E e) => e == _E.a || e == _E.b;
     ]);
   }
 
+  test_privateExtensionType() async {
+    await assertErrorsInCode(r'''
+import 'package:meta/meta.dart';
+@visibleForTesting extension type _E(int i) {}
+''', [
+      error(WarningCode.INVALID_VISIBILITY_ANNOTATION, 33, 18),
+      error(WarningCode.UNUSED_ELEMENT, 67, 2),
+    ]);
+  }
+
   test_privateField() async {
     await assertErrorsInCode(r'''
 import 'package:meta/meta.dart';
@@ -187,6 +197,10 @@ import 'package:meta/meta.dart';
 @visibleForTesting enum E {a, b, c}
 @visibleForTesting typedef T = Function();
 @visibleForTesting class C1 {}
+@visibleForTesting extension type ET1(int i) {}
+extension type ET2(int i) {
+  @visibleForTesting void m() {}
+}
 @visibleForTesting mixin M {}
 class C2 {
   @visibleForTesting C2.named() {}