Elements. Update RemoveUnusedElement to use FragmentDeclaration and LocalFunctionDeclarationView.

Change-Id: I8dee4c04e372e3312959ba7f3aafd79765677298
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/389592
Reviewed-by: Phil Quitslund <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analysis_server/lib/src/services/correction/dart/remove_unused.dart

@@ -4,11 +4,11 @@
 
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analysis_server_plugin/edit/dart/correction_producer.dart';
-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/element2.dart';
 import 'package:analyzer/source/source_range.dart';
+import 'package:analyzer/src/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/ast/extensions.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
@@ -39,17 +39,12 @@ class RemoveUnusedElement extends _RemoveUnused {
       return;
     }
 
-    var element = switch (node) {
-      ClassDeclaration() => node.declaredFragment?.element,
-      EnumDeclaration() => node.declaredFragment?.element,
-      FunctionDeclaration() =>
-        node.declaredElement2 ?? node.declaredFragment?.element,
-      FunctionTypeAlias() => node.declaredFragment?.element,
-      GenericTypeAlias() => node.declaredFragment?.element,
-      MethodDeclaration() => node.declaredFragment?.element,
-      VariableDeclaration() => node.declaredFragment?.element,
-      _ => null,
-    };
+    Element2? element;
+    if (LocalFunctionDeclarationView.of(node) case var localFunction?) {
+      element = localFunction.declaredElement;
+    } else if (node is FragmentDeclaration) {
+      element = node.declaredFragment?.element;
+    }
     if (element == null) {
       return;
     }

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -11447,6 +11447,26 @@ sealed class LiteralImpl extends ExpressionImpl implements Literal {
   Precedence get precedence => Precedence.primary;
 }
 
+// TODO(scheglov): parse into actual `LocalFunctionDeclarationImpl`.
+class LocalFunctionDeclarationView {
+  final FunctionDeclarationImpl declaration;
+
+  LocalFunctionDeclarationView(this.declaration);
+
+  LocalFunctionElement? get declaredElement {
+    return declaration.declaredElement2;
+  }
+
+  static LocalFunctionDeclarationView? of(AstNode declaration) {
+    if (declaration is FunctionDeclarationImpl) {
+      if (declaration.parent is FunctionDeclarationStatement) {
+        return LocalFunctionDeclarationView(declaration);
+      }
+    }
+    return null;
+  }
+}
+
 /// Additional information about local variables within a function or method
 /// produced at resolution time.
 class LocalVariableInfo {