Impements 'names', 'offsets' and 'lengths' for ExtractMethodRefactoring.

pkg/analysis_server/test/services/refactoring/extract_method_test.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 test.services.refactoring.extract_method;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/refactoring/extract_method.dart';
@@ skipping 992 matching lines @@
 class A {
   main() {
     print(1 + 2);
   }
 }
 ''');
     _createRefactoringForString('1 + 2');
     expect(refactoring.refactoringName, 'Extract Method');
   }
 
+  test_names_singleExpression() {
+    indexTestUnit('''
+class TreeItem {}
+TreeItem getSelectedItem() => null;
+process(my) {}
+main() {
+  process(getSelectedItem()); // marker
+  int treeItem = 0;
+}
+''');
+    _createRefactoringWithSuffix('getSelectedItem()', '); // marker');
+    // check names
+    return refactoring.checkInitialConditions().then((_) {
+      expect(
+          refactoring.names,
+          unorderedEquals(['selectedItem', 'item', 'my', 'treeItem2']));
+    });
+  }
+
+  test_offsets_lengths() {
+    indexTestUnit('''
+main() {
+main() {
+  int a = 1 + 2;
+  int b = 1 +  2;
+}
+}
+''');
+    _createRefactoringForString('1 +  2');
+    // apply refactoring
+    return refactoring.checkInitialConditions().then((_) {
+      expect(
+          refactoring.offsets,
+          unorderedEquals([findOffset('1 + 2'), findOffset('1 +  2')]));
+      expect(refactoring.lengths, unorderedEquals([5, 6]));
+    });
+  }
+
   test_setExtractGetter() {
     indexTestUnit('''
 main() {
   int a = 1 + 2;
 }
 ''');
     _createRefactoringForString('1 + 2');
     // apply refactoring
     return assertRefactoringConditionsOK().then((_) {
       expect(refactoring.canCreateGetter, true);
@@ skipping 1194 matching lines @@
     int length = search.length;
     _createRefactoring(offset, length);
   }
 
   void _createRefactoringWithSuffix(String selectionSearch, String suffix) {
     int offset = findOffset(selectionSearch + suffix);
     int length = selectionSearch.length;
     _createRefactoring(offset, length);
   }
 }