Stop depending on LabelElement(s) to be reported in visitChildren().

pkg/analyzer_plugin/test/support/abstract_context.dart

 // Copyright (c) 2017, 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 'dart:async';
 
 import 'package:analyzer/dart/analysis/session.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/visitor.dart';
 import 'package:analyzer/exception/exception.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/dart/analysis/file_state.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/engine.dart' as engine;
@@ skipping 15 matching lines @@
     }
     if (kind != null && element.kind != kind) {
       return;
     }
     result = element;
   }));
   return result;
 }
 
 /**
+ * Search the [unit] for the [Element]s with the given [name].
+ */
+List<Element> findElementsByName(CompilationUnit unit, String name) {

[Brian Wilkerson, 2017/07/06 18:19:18]

Can we use the copy in pkg/analyzer/test/utils.dart?

+  var finder = new _ElementsByNameFinder(name);
+  unit.accept(finder);
+  return finder.elements;
+}
+
+/**
  * A function to be called for every [Element].
  */
 typedef void _ElementVisitorFunction(Element element);
 
 class AbstractContextTest {
   MemoryResourceProvider provider;
   DartSdk sdk;
   Map<String, List<Folder>> packageMap;
   UriResolver resourceResolver;
 
@@ skipping 38 matching lines @@
       path = provider.convertPath(path);
     }
     driver.addFile(path);
     driver.changeFile(path);
     _fileContentOverlay[path] = content;
     return provider.getFile(path).createSource();
   }
 
   Element findElementInUnit(CompilationUnit unit, String name,
       [ElementKind kind]) {
-    return findChildElement(unit.element, name, kind);
+    return findElementsByName(unit, name)
+        .where((e) => kind == null || e.kind == kind)
+        .single;
   }
 
   File newFile(String path, [String content]) =>
       provider.newFile(provider.convertPath(path), content ?? '');
 
   Folder newFolder(String path) =>
       provider.newFolder(provider.convertPath(path));
 
   void processRequiredPlugins() {
     AnalysisEngine.instance.processRequiredPlugins();
@@ skipping 57 matching lines @@
 
   @override
   void logInformation(String message, [CaughtException exception]) {
     print(message);
     if (exception != null) {
       print(exception);
     }
   }
 }
 
+class _ElementsByNameFinder extends RecursiveAstVisitor<Null> {
+  final String name;
+  final List<Element> elements = [];
+
+  _ElementsByNameFinder(this.name);
+
+  @override
+  visitSimpleIdentifier(SimpleIdentifier node) {
+    if (node.name == name && node.inDeclarationContext()) {
+      elements.add(node.staticElement);
+    }
+  }
+}
+
 /**
  * Wraps the given [_ElementVisitorFunction] into an instance of
  * [engine.GeneralizingElementVisitor].
  */
 class _ElementVisitorFunctionWrapper extends GeneralizingElementVisitor {
   final _ElementVisitorFunction function;
 
   _ElementVisitorFunctionWrapper(this.function);
 
   @override
   visitElement(Element element) {
     function(element);
     super.visitElement(element);
   }
 }