use_named_constants constant pattern tests (#4211)

Author: pq

test/rules/all.dart

@@ -127,6 +127,7 @@ import 'use_is_even_rather_than_modulo_test.dart'
     as use_is_even_rather_than_modulo;
 import 'use_late_for_private_fields_and_variables_test.dart'
     as use_late_for_private_fields_and_variables;
+import 'use_named_constants_test.dart' as use_named_constants;
 import 'use_super_parameters_test.dart' as use_super_parameters;
 import 'void_checks_test.dart' as void_checks;
 
@@ -222,6 +223,7 @@ void main() {
   use_enums.main();
   use_is_even_rather_than_modulo.main();
   use_late_for_private_fields_and_variables.main();
+  use_named_constants.main();
   use_super_parameters.main();
   void_checks.main();
 }

test/rules/use_named_constants_test.dart

@@ -0,0 +1,59 @@
+// Copyright (c) 2023, 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(UseNamedConstantsTestLanguage300);
+  });
+}
+
+@reflectiveTest
+class UseNamedConstantsTestLanguage300 extends LintRuleTest
+    with LanguageVersion300Mixin {
+  @override
+  String get lintRule => 'use_named_constants';
+
+  /// https://github.com/dart-lang/linter/issues/4201
+  test_constantPattern_ifCase() async {
+    await assertDiagnostics(r'''
+class A {
+  const A(this.value);
+  final int value;
+
+  static const zero = A(0);
+}
+
+void f(A a) {
+  if (a case const A(0)) print(a);
+}
+''', [
+      lint(117, 4),
+    ]);
+  }
+
+  /// https://github.com/dart-lang/linter/issues/4201
+  test_constantPattern_switch() async {
+    await assertDiagnostics(r'''
+class A {
+  const A(this.value);
+  final int value;
+
+  static const zero = A(0);
+  static const one = A(1);
+}
+
+void f(A a) {
+  switch (a) {
+    case const A(1):
+  }
+}
+''', [
+      lint(155, 4),
+    ]);
+  }
+}