extension type support for camel_case_types

Fixes: https://github.com/dart-lang/linter/issues/4716

Change-Id: I0ced3926c13f92c471df537621fa18429c4982b1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322567
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Phil Quitslund <[email protected]>

Author: pq

pkg/linter/lib/src/rules/camel_case_types.dart

@@ -59,6 +59,7 @@ class CamelCaseTypes extends LintRule {
     registry.addClassTypeAlias(this, visitor);
     registry.addFunctionTypeAlias(this, visitor);
     registry.addEnumDeclaration(this, visitor);
+    registry.addExtensionTypeDeclaration(this, visitor);
   }
 }
 
@@ -89,6 +90,11 @@ class _Visitor extends SimpleAstVisitor<void> {
     check(node.name);
   }
 
+  @override
+  void visitExtensionTypeDeclaration(ExtensionTypeDeclaration node) {
+    check(node.name);
+  }
+
   @override
   void visitFunctionTypeAlias(FunctionTypeAlias node) {
     check(node.name);

pkg/linter/test/rules/all.dart

@@ -41,6 +41,7 @@ import 'avoid_unused_constructor_parameters_test.dart'
 import 'avoid_void_async_test.dart' as avoid_void_async;
 import 'await_only_futures_test.dart' as await_only_futures;
 import 'camel_case_extensions_test.dart' as camel_case_extensions;
+import 'camel_case_types_test.dart' as camel_case_types;
 import 'cancel_subscriptions_test.dart' as cancel_subscriptions;
 import 'cast_nullable_to_non_nullable_test.dart'
     as cast_nullable_to_non_nullable;
@@ -251,6 +252,7 @@ void main() {
   avoid_void_async.main();
   await_only_futures.main();
   camel_case_extensions.main();
+  camel_case_types.main();
   cancel_subscriptions.main();
   cast_nullable_to_non_nullable.main();
   collection_methods_unrelated_type.main();

pkg/linter/test/rules/camel_case_types_test.dart

@@ -0,0 +1,35 @@
+// 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(CamelCaseTypesTest);
+  });
+}
+
+@reflectiveTest
+class CamelCaseTypesTest extends LintRuleTest {
+  @override
+  String get lintRule => 'camel_case_types';
+
+  test_extensionType_lowerCase() async {
+    // No need to test all the variations. Name checking is shared with other
+    // declaration types.
+    await assertDiagnostics(r'''
+extension type fooBar(int i) {}
+''', [
+      lint(15, 6),
+    ]);
+  }
+
+  test_extensionType_wellFormed() async {
+    await assertNoDiagnostics(r'''
+extension type FooBar(int i) {}
+''');
+  }
+}