Fix for 'Rename Local' refactoring without tasks.

pkg/analysis_server/lib/src/services/refactoring/rename_local.dart

 // Copyright (c) 2014, 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.
 
 library services.src.refactoring.rename_local;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/correction/util.dart';
 import 'package:analysis_server/src/services/refactoring/naming_conventions.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/services/refactoring/rename.dart';
 import 'package:analysis_server/src/services/search/hierarchy.dart';
 import 'package:analysis_server/src/services/search/search_engine.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/src/dart/element/ast_provider.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 
 /**
  * A [Refactoring] for renaming [LocalElement]s.
  */
 class RenameLocalRefactoringImpl extends RenameRefactoringImpl {
+  final AstProvider astProvider;
+  final ResolvedUnitCache unitCache;
+
   Set<LocalElement> elements = new Set<LocalElement>();
 
-  RenameLocalRefactoringImpl(SearchEngine searchEngine, LocalElement element)
-      : super(searchEngine, element);
+  RenameLocalRefactoringImpl(
+      SearchEngine searchEngine, this.astProvider, LocalElement element)
+      : unitCache = new ResolvedUnitCache(astProvider),
+        super(searchEngine, element);
 
   @override
   LocalElement get element => super.element as LocalElement;
 
   @override
   String get refactoringName {
     if (element is ParameterElement) {
       return "Rename Parameter";
     }
     if (element is FunctionElement) {
       return "Rename Local Function";
     }
     return "Rename Local Variable";
   }
 
   @override
   Future<RefactoringStatus> checkFinalConditions() async {
     RefactoringStatus result = new RefactoringStatus();
-    // prepare all elements (usually one)
     await _prepareElements();
-    // checks the resolved CompilationUnit(s)
     for (LocalElement element in elements) {
-      Source unitSource = element.source;
-      List<Source> librarySources = context.getLibrariesContaining(unitSource);
-      for (Source librarySource in librarySources) {
-        _analyzePossibleConflicts_inLibrary(
-            result, unitSource, librarySource, element);
+      CompilationUnit unit = await unitCache.getUnit(element);
+      if (unit != null) {
+        SourceRange elementRange = element.visibleRange;
+        unit.accept(new _ConflictValidatorVisitor(this, result, elementRange));
       }
     }
-    // done
     return result;
   }
 
   @override
   RefactoringStatus checkNewName() {
     RefactoringStatus result = super.checkNewName();
     if (element is LocalVariableElement) {
       result.addStatus(validateVariableName(newName));
     } else if (element is ParameterElement) {
       result.addStatus(validateParameterName(newName));
     } else if (element is FunctionElement) {
       result.addStatus(validateFunctionName(newName));
     }
     return result;
   }
 
   @override
   Future fillChange() async {
     for (Element element in elements) {
       addDeclarationEdit(element);
       await searchEngine.searchReferences(element).then(addReferenceEdits);
     }
   }
 
-  void _analyzePossibleConflicts_inLibrary(RefactoringStatus result,
-      Source unitSource, Source librarySource, LocalElement element) {
-    // prepare resolved unit
-    CompilationUnit unit = null;
-    try {
-      unit = context.resolveCompilationUnit2(unitSource, librarySource);
-    } catch (e) {}
-    if (unit == null) {
-      return;
-    }
-    // check for conflicts in the unit
-    SourceRange elementRange = element.visibleRange;
-    unit.accept(new _ConflictValidatorVisitor(this, result, elementRange));
-  }
-
   /**
    * Fills [elements] with [Element]s to rename.
    */
   Future _prepareElements() async {
     Element enclosing = element.enclosingElement;
     if (enclosing is MethodElement &&
         element is ParameterElement &&
         (element as ParameterElement).parameterKind == ParameterKind.NAMED) {
       // prepare hierarchy methods
       Set<ClassMemberElement> methods =
@@ skipping 54 matching lines @@
             '"$nameElementSourceName" will be shadowed by renamed $refKind.';
         result.addError(message, newLocation_fromNode(node));
       }
     }
   }
 
   static bool _isNamedExpressionName(SimpleIdentifier node) {
     return node.parent is Label && node.parent.parent is NamedExpression;
   }
 }