Test for 'search.findElementReferences' for the case when there is no element.

pkg/analysis_server/test/search/element_references_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.search.element_references;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:unittest/unittest.dart';
 
 import 'abstract_search_domain.dart';
 
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(ElementReferencesTest);
 }
 
 
 @ReflectiveTestCase()
 class ElementReferencesTest extends AbstractSearchDomainTest {
   Element searchElement;
 
   Future findElementReferences(String search, bool includePotential) {
     int offset = findOffset(search);
     return waitForTasksFinished().then((_) {
-      Request request = new SearchFindElementReferencesParams(testFile, offset,
+      Request request = new SearchFindElementReferencesParams(
+          testFile,
+          offset,
           includePotential).toRequest('0');
       Response response = handleSuccessfulRequest(request);
       var result = new SearchFindElementReferencesResult.fromResponse(response);
       searchId = result.id;
       searchElement = result.element;
       results.clear();
       if (searchId == null) {
         return null;
       } else {
         return waitForSearchResults();
@@ skipping 252 matching lines @@
 }
 ''');
     return findElementReferences('mmm(p) {}', false).then((_) {
       expect(searchElement.kind, ElementKind.METHOD);
       expect(results, hasLength(2));
       assertHasResult(SearchResultKind.INVOCATION, 'mmm(10);');
       assertHasResult(SearchResultKind.REFERENCE, 'mmm);');
     });
   }
 
+  test_noElement() {
+    addTestFile('''
+main() {
+  print(noElement);
+}
+''');
+    return findElementReferences('noElement', false).then((_) {
+      expect(searchId, isNull);
+    });
+  }
+
   test_oneUnit_twoLibraries() {
     var pathA = '/project/bin/libA.dart';
     var pathB = '/project/bin/libB.dart';
     var codeA = '''
 library lib;
 part 'test.dart';
 main() {
   fff(1);
 }
 ''';
@@ skipping 265 matching lines @@
 }
 ''');
     return findElementReferences('T> {', false).then((_) {
       expect(searchElement.kind, ElementKind.TYPE_PARAMETER);
       expect(results, hasLength(2));
       assertHasResult(SearchResultKind.REFERENCE, 'T f;');
       assertHasResult(SearchResultKind.REFERENCE, 'T m()');
     });
   }
 }