Fix type hierarchy when there is no element.

pkg/analysis_server/test/analysis_abstract.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.domain.analysis.abstract;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:unittest/unittest.dart';
 
 import 'mock_sdk.dart';
 import 'mocks.dart';
+import 'package:analysis_server/src/constants.dart';
 
 
 int findIdentifierLength(String search) {
   int length = 0;
   while (length < search.length) {
     int c = search.codeUnitAt(length);
     if (!(c >= 'a'.codeUnitAt(0) && c <= 'z'.codeUnitAt(0) ||
         c >= 'A'.codeUnitAt(0) && c <= 'Z'.codeUnitAt(0) ||
         c >= '0'.codeUnitAt(0) && c <= '9'.codeUnitAt(0))) {
       break;
     }
     length++;
   }
   return length;
 }
 
 
 /**
  * An abstract base for all 'analysis' domain tests.
  */
 class AbstractAnalysisTest {
   MockServerChannel serverChannel;
   MemoryResourceProvider resourceProvider;
   MockPackageMapProvider packageMapProvider;
   AnalysisServer server;
   RequestHandler handler;
 
-  Map<AnalysisService, List<String>> analysisSubscriptions = {};
+  final List<ServerErrorParams> serverErrors = <ServerErrorParams>[];
+  final Map<AnalysisService, List<String>> analysisSubscriptions = {};
 
   String projectPath = '/project';
   String testFolder = '/project/bin/';
   String testFile = '/project/bin/test.dart';
   String testCode;
 
   AbstractAnalysisTest();
 
   void addAnalysisSubscription(AnalysisService service, String file) {
     // add file to subscription
@@ skipping 76 matching lines @@
     return response;
   }
 
   String modifyTestFile(String content) {
     addFile(testFile, content);
     this.testCode = content;
     return testFile;
   }
 
   void processNotification(Notification notification) {
+    if (notification.event == SERVER_ERROR) {
+      var params = new ServerErrorParams.fromNotification(notification);
+      serverErrors.add(params);
+    }
   }
 
   void setUp() {
     serverChannel = new MockServerChannel();
     resourceProvider = new MemoryResourceProvider();
     packageMapProvider = new MockPackageMapProvider();
     Index index = createIndex();
     server = createAnalysisServer(index);
     handler = new AnalysisDomainHandler(server);
     // listen for notifications
@@ skipping 20 matching lines @@
   }
 
   /**
    * Completes with a successful [Response] for the given [request].
    * Otherwise fails.
    */
   Future<Response> waitResponse(Request request) async {
     return serverChannel.sendRequest(request);
   }
 }