[element model] migrate avoid_void_async

Bug: https://github.com/dart-lang/linter/issues/5099
Change-Id: I9b7f68540c3a950ddd673da7eac04e9c2cdc1614
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/390782
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Phil Quitslund <[email protected]>

Author: pq

pkg/linter/analyzer_use_new_elements.txt

@@ -1,7 +1,6 @@
 lib/src/ast.dart
 lib/src/extensions.dart
 lib/src/rules/avoid_setters_without_getters.dart
-lib/src/rules/avoid_void_async.dart
 lib/src/rules/deprecated_member_use_from_same_package.dart
 lib/src/rules/invalid_runtime_check_with_js_interop_types.dart
 lib/src/rules/prefer_asserts_in_initializer_lists.dart

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

@@ -5,7 +5,7 @@
 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';
+import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/dart/element/type.dart';
 
 import '../analyzer.dart';
@@ -40,31 +40,27 @@ class _Visitor extends SimpleAstVisitor<void> {
   void visitFunctionDeclaration(FunctionDeclaration node) {
     if (node.name.lexeme == 'main' && node.parent is CompilationUnit) return;
     _check(
-      declaredElement: node.declaredElement,
-      returnType: node.returnType,
+      fragment: node.declaredFragment,
       errorNode: node.name,
     );
   }
 
   @override
   void visitMethodDeclaration(MethodDeclaration node) {
     _check(
-      declaredElement: node.declaredElement,
-      returnType: node.returnType,
+      fragment: node.declaredFragment,
       errorNode: node.name,
     );
   }
 
   void _check({
-    required ExecutableElement? declaredElement,
-    required TypeAnnotation? returnType,
+    required ExecutableFragment? fragment,
     required Token errorNode,
   }) {
-    if (declaredElement == null) return;
-    if (declaredElement.isGenerator) return;
-    if (!declaredElement.isAsynchronous) return;
-    if (returnType == null) return;
-    if (returnType.type is VoidType) {
+    if (fragment == null) return;
+    if (fragment.isGenerator) return;
+    if (!fragment.isAsynchronous) return;
+    if (fragment.element.returnType is VoidType) {
       rule.reportLintForToken(errorNode);
     }
   }

pkg/linter/test/rules/avoid_void_async_test.dart

@@ -145,6 +145,17 @@ void get f => null;
 ''');
   }
 
+  test_localFunction_async() async {
+    await assertDiagnostics(r'''
+Future<void> f() async {
+  void g() async {}
+}
+''', [
+      error(WarningCode.UNUSED_ELEMENT, 32, 1),
+      lint(32, 1),
+    ]);
+  }
+
   test_main_async() async {
     await assertNoDiagnostics(r'''
 Future<void> f() async { }