[wildcards] support for avoid_types_as_parameter_names

Fixes: https://github.com/dart-lang/linter/issues/5051

(Depends on https://dart-review.googlesource.com/c/sdk/+/379506.)


Change-Id: Ic94d24ed1e260bb2b068d298fa412c64cdae0f78
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/379527
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Phil Quitslund <[email protected]>

Author: pq

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

@@ -6,6 +6,8 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
+// ignore: implementation_imports
+import 'package:analyzer/src/dart/element/extensions.dart';
 
 import '../analyzer.dart';
 import '../util/scope.dart';
@@ -91,7 +93,7 @@ class _Visitor extends SimpleAstVisitor<void> {
       return element is ClassElement ||
           element is ExtensionTypeElement ||
           element is TypeAliasElement ||
-          element is TypeParameterElement;
+          (element is TypeParameterElement && !element.isWildcardVariable);
     }
     return false;
   }

pkg/linter/test/rules/avoid_types_as_parameter_names_test.dart

@@ -40,4 +40,15 @@ class B extends A {
       lint(67, 6),
     ]);
   }
+
+  test_typeParameter_wildcard() async {
+    await assertDiagnostics(r'''
+class C<_> {
+  var _;
+  C.c(this._, _);
+}
+''', [
+      error(WarningCode.UNUSED_FIELD, 19, 1),
+    ]);
+  }
 }