enhanced enums tests for unnecessary_overrides (#3187)

* enhanced enums tests for `unnecessary_overrides`

* fmt

Author: pq

test/rules/all.dart

@@ -45,6 +45,7 @@ import 'tighten_type_of_initializing_formals.dart'
 import 'type_init_formals.dart' as type_init_formals;
 import 'unawaited_futures.dart' as unawaited_futures;
 import 'unnecessary_null_checks.dart' as unnecessary_null_checks;
+import 'unnecessary_overrides.dart' as unnecessary_overrides;
 import 'use_is_even_rather_than_modulo.dart' as use_is_even_rather_than_modulo;
 import 'void_checks.dart' as void_checks;
 
@@ -80,6 +81,7 @@ void main() {
   type_init_formals.main();
   unawaited_futures.main();
   unnecessary_null_checks.main();
+  unnecessary_overrides.main();
   use_is_even_rather_than_modulo.main();
   void_checks.main();
 }

test/rules/unnecessary_overrides.dart

@@ -0,0 +1,50 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. 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:test_reflective_loader/test_reflective_loader.dart';
+
+import '../rule_test_support.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(UnnecessaryOverridesTest);
+  });
+}
+
+@reflectiveTest
+class UnnecessaryOverridesTest extends LintRuleTest {
+  @override
+  List<String> get experiments => [
+        EnableString.enhanced_enums,
+      ];
+
+  @override
+  String get lintRule => 'unnecessary_overrides';
+
+  @FailingTest(issue: 'https://github.com/dart-lang/linter/issues/3097')
+  test_field() async {
+    await assertDiagnostics(r'''
+enum A {
+  a,b,c;
+  @override
+  int get foo => 0;
+}
+''', [
+      lint('unnecessary_overrides', 28, 8),
+    ]);
+  }
+
+  @FailingTest(issue: 'https://github.com/dart-lang/linter/issues/3097')
+  test_method() async {
+    await assertDiagnostics(r'''
+enum A {
+  a,b,c;
+  @override
+  String bar() => '';
+}
+''', [
+      lint('unnecessary_overrides', 27, 8),
+    ]);
+  }
+}