Make AssistContributor asynchronous.

pkg/analysis_server/test/edit/assists_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.edit.assists;
 
-import 'dart:async';
-
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/edit/edit_domain.dart';
 import 'package:plugin/manager.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart' hide ERROR;
 
 import '../analysis_abstract.dart';
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(AssistsTest);
 }
 
 @reflectiveTest
 class AssistsTest extends AbstractAnalysisTest {
   List<SourceChange> changes;
 
-  void prepareAssists(String search, [int length = 0]) {
+  prepareAssists(String search, [int length = 0]) async {
     int offset = findOffset(search);
-    prepareAssistsAt(offset, length);
+    await prepareAssistsAt(offset, length);
   }
 
-  void prepareAssistsAt(int offset, int length) {
+  prepareAssistsAt(int offset, int length) async {
     Request request =
         new EditGetAssistsParams(testFile, offset, length).toRequest('0');
-    Response response = handleSuccessfulRequest(request);
+    Response response = await waitResponse(request);
     var result = new EditGetAssistsResult.fromResponse(response);
     changes = result.assists;
   }
 
   @override
   void setUp() {
     super.setUp();
     createProject();
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins([server.serverPlugin]);
     handler = new EditDomainHandler(server);
   }
 
-  Future test_removeTypeAnnotation() async {
+  test_removeTypeAnnotation() async {
     addTestFile('''
 main() {
   int v = 1;
 }
 ''');
     await waitForTasksFinished();
-    prepareAssists('v =');
+    await prepareAssists('v =');
     _assertHasChange(
         'Remove type annotation',
         '''
 main() {
   var v = 1;
 }
 ''');
   }
 
-  Future test_splitVariableDeclaration() async {
+  test_splitVariableDeclaration() async {
     addTestFile('''
 main() {
   int v = 1;
 }
 ''');
     await waitForTasksFinished();
-    prepareAssists('v =');
+    await prepareAssists('v =');
     _assertHasChange(
         'Split variable declaration',
         '''
 main() {
   int v;
   v = 1;
 }
 ''');
   }
 
-  Future test_surroundWithIf() async {
+  test_surroundWithIf() async {
     addTestFile('''
 main() {
   print(1);
   print(2);
 }
 ''');
     await waitForTasksFinished();
     int offset = findOffset('  print(1)');
     int length = findOffset('}') - offset;
-    prepareAssistsAt(offset, length);
+    await prepareAssistsAt(offset, length);
     _assertHasChange(
         "Surround with 'if'",
         '''
 main() {
   if (condition) {
     print(1);
     print(2);
   }
 }
 ''');
   }
 
   void _assertHasChange(String message, String expectedCode) {
     for (SourceChange change in changes) {
       if (change.message == message) {
         String resultCode =
             SourceEdit.applySequence(testCode, change.edits[0].edits);
         expect(resultCode, expectedCode);
         return;
       }
     }
     fail("Expected to find |$message| in\n" + changes.join('\n'));
   }
 }