Skip assignments and argument lists.

pkg/analysis_server/lib/src/services/refactoring/extract_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.extract_local;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
@@ skipping 179 matching lines @@
       int numLeading = countLeadingWhitespaces(selectionStr);
       int numTrailing = countTrailingWhitespaces(selectionStr);
       int offset = selectionRange.offset + numLeading;
       int end = selectionRange.end - numTrailing;
       selectionRange = new SourceRange(offset, end - offset);
     }
     // get covering node
     AstNode coveringNode = new NodeLocator(
         selectionRange.offset, selectionRange.end).searchWithin(unit);
     // compute covering expressions
-    for (AstNode node = coveringNode; node is Expression; node = node.parent) {
+    for (AstNode node = coveringNode;
+        node is Expression || node is ArgumentList;
+        node = node.parent) {
       AstNode parent = node.parent;
+      // skip ArgumentList
+      if (node is ArgumentList) {
+        continue;
+      }
+      // skip AssignmentExpression
+      if (node is AssignmentExpression) {
+        continue;
+      }
       // cannot extract the name part of a property access
       if (parent is PrefixedIdentifier && parent.identifier == node ||
           parent is PropertyAccess && parent.propertyName == node) {
         continue;
       }
       // fatal selection problems
       if (coveringExpressionOffsets.isEmpty) {
         if (node is SimpleIdentifier) {
           if (node.inDeclarationContext()) {
             return new RefactoringStatus.fatal(
@@ skipping 407 matching lines @@
 
   _TokenLocalElementVisitor(this.map);
 
   visitSimpleIdentifier(SimpleIdentifier node) {
     Element element = node.staticElement;
     if (element is LocalVariableElement) {
       map[node.token] = element;
     }
   }
 }