Fix for extracting local variable in if-else-if statements.

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 122 matching lines @@
       String declarationSource;
       if (stringLiteralPart != null) {
         declarationSource = "var $name = '$stringLiteralPart';";
       } else {
         String keyword = _declarationKeyword;
         String initializerSource = utils.getRangeText(selectionRange);
         declarationSource = "$keyword $name = $initializerSource;";
       }
       String eol = utils.endOfLine;
       // prepare location for declaration
-      AstNode target_;
-      {
-        List<AstNode> nodes = _findNodes(occurrences);
-        AstNode commonParent = getNearestCommonAncestor(nodes);
-        if (commonParent is Block) {
-          List<AstNode> firstParents = getParents(nodes[0]);
-          int commonIndex = firstParents.indexOf(commonParent);
-          target_ = firstParents[commonIndex + 1];
-        } else {
-          target_ = _getEnclosingExpressionBody(commonParent);
-          if (target_ == null) {
-            target_ = commonParent.getAncestor((node) => node is Statement);
-          }
-        }
-      }
-      AstNode target = target_;
+      AstNode target = _findDeclarationTarget(occurrences);
       // insert variable declaration
       if (target is Statement) {
         String prefix = utils.getNodePrefix(target);
         SourceEdit edit =
             new SourceEdit(target.offset, 0, declarationSource + eol + prefix);
         doSourceChange_addElementEdit(change, unitElement, edit);
       } else if (target is ExpressionFunctionBody) {
         String prefix = utils.getNodePrefix(target.parent);
         String indent = utils.getIndent(1);
         String declStatement = prefix + indent + declarationSource + eol;
@@ skipping 138 matching lines @@
         if (elementId != null) {
           tokenString += '-$elementId';
         }
       }
       // done
       return tokenString;
     }).join(_TOKEN_SEPARATOR);
   }
 
   /**
+   * Return the [AstNode] to defined the variable before.
+   * It should be accessible by all the given [occurrences].
+   */
+  AstNode _findDeclarationTarget(List<SourceRange> occurrences) {
+    List<AstNode> nodes = _findNodes(occurrences);
+    AstNode commonParent = getNearestCommonAncestor(nodes);
+    // Block
+    if (commonParent is Block) {
+      List<AstNode> firstParents = getParents(nodes[0]);
+      int commonIndex = firstParents.indexOf(commonParent);
+      return firstParents[commonIndex + 1];
+    }
+    // ExpressionFunctionBody
+    AstNode expressionBody = _getEnclosingExpressionBody(commonParent);
+    if (expressionBody != null) {
+      return expressionBody;
+    }
+    // single Statement
+    AstNode target = commonParent.getAncestor((node) => node is Statement);
+    while (target.parent is! Block) {
+      target = target.parent;
+    }
+    return target;
+  }
+
+  /**
    * Returns [AstNode]s at the offsets of the given [SourceRange]s.
    */
   List<AstNode> _findNodes(List<SourceRange> ranges) {
     List<AstNode> nodes = <AstNode>[];
     for (SourceRange range in ranges) {
       AstNode node = new NodeLocator.con1(range.offset).searchWithin(unit);
       nodes.add(node);
     }
     return nodes;
   }
@@ skipping 302 matching lines @@
 
   _TokenLocalElementVisitor(this.map);
 
   visitSimpleIdentifier(SimpleIdentifier node) {
     Element element = node.staticElement;
     if (element is LocalVariableElement) {
       map[node.token] = element;
     }
   }
 }