Pass target elements being renamed into validator.

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

Index: pkg/analysis_server/lib/src/services/refactoring/rename_local.dart
diff --git a/pkg/analysis_server/lib/src/services/refactoring/rename_local.dart b/pkg/analysis_server/lib/src/services/refactoring/rename_local.dart
index ac9105150699600e0482b0f80b49f4da6c8c4d0b..85f86e4aa837d9f6bf0dc93f07ac659086f39baf 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/rename_local.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/rename_local.dart
@@ -4,7 +4,8 @@
 
 import 'dart:async';
 
-import 'package:analysis_server/src/protocol_server.dart' hide Element;
+import 'package:analysis_server/src/protocol_server.dart'
+    hide Element, ElementKind;
 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';
@@ -54,8 +55,7 @@ class RenameLocalRefactoringImpl extends RenameRefactoringImpl {
     for (LocalElement element in elements) {
       CompilationUnit unit = await unitCache.getUnit(element);
       if (unit != null) {
-        SourceRange elementRange = element.visibleRange;
-        unit.accept(new _ConflictValidatorVisitor(this, result, elementRange));
+        unit.accept(new _ConflictValidatorVisitor(result, newName, element));
       }
     }
     return result;
@@ -111,21 +111,19 @@ class RenameLocalRefactoringImpl extends RenameRefactoringImpl {
 }
 
 class _ConflictValidatorVisitor extends RecursiveAstVisitor {
-  final RenameLocalRefactoringImpl refactoring;
   final RefactoringStatus result;
-  final SourceRange elementRange;
+  final String newName;
+  final LocalElement target;
   final Set<Element> conflictingLocals = new Set<Element>();
 
-  _ConflictValidatorVisitor(this.refactoring, this.result, this.elementRange);
+  _ConflictValidatorVisitor(this.result, this.newName, this.target);
 
   @override
   visitSimpleIdentifier(SimpleIdentifier node) {
     Element nodeElement = node.bestElement;
-    String newName = refactoring.newName;
     if (nodeElement != null && nodeElement.name == newName) {
-      // duplicate declaration
-      if (node.inDeclarationContext() &&
-          haveIntersectingRanges(refactoring.element, nodeElement)) {
+      // Duplicate declaration.
+      if (node.inDeclarationContext() && _isVisibleWithTarget(nodeElement)) {
         conflictingLocals.add(nodeElement);
         String nodeKind = nodeElement.kind.displayName;
         String message = "Duplicate $nodeKind '$newName'.";
@@ -135,16 +133,17 @@ class _ConflictValidatorVisitor extends RecursiveAstVisitor {
       if (conflictingLocals.contains(nodeElement)) {
         return;
       }
-      // shadowing referenced element
-      if (elementRange != null &&
-          elementRange.contains(node.offset) &&
+      // Shadowing by the target element.
+      SourceRange targetRange = target.visibleRange;
+      if (targetRange != null &&
+          targetRange.contains(node.offset) &&
           !node.isQualified &&
           !_isNamedExpressionName(node)) {
         nodeElement = getSyntheticAccessorVariable(nodeElement);
         String nodeKind = nodeElement.kind.displayName;
         String nodeName = getElementQualifiedName(nodeElement);
         String nameElementSourceName = nodeElement.source.shortName;
-        String refKind = refactoring.element.kind.displayName;
+        String refKind = target.kind.displayName;
         String message = 'Usage of $nodeKind "$nodeName" declared in '
             '"$nameElementSourceName" will be shadowed by renamed $refKind.';
         result.addError(message, newLocation_fromNode(node));
@@ -152,6 +151,20 @@ class _ConflictValidatorVisitor extends RecursiveAstVisitor {
     }
   }
 
+  /**
+   * Returns whether [element] and [target] are visible together.
+   */
+  bool _isVisibleWithTarget(Element element) {
+    if (element is LocalElement) {
+      SourceRange targetRange = target.visibleRange;
+      SourceRange elementRange = element.visibleRange;
+      return targetRange != null &&
+          elementRange != null &&
+          elementRange.intersects(targetRange);
+    }
+    return false;
+  }
+
   static bool _isNamedExpressionName(SimpleIdentifier node) {
     return node.parent is Label && node.parent.parent is NamedExpression;
   }