Create a public API for contributing fixes and make fixes pluggable

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/src/edit/edit_domain.dart';
+import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analysis_server/src/protocol.dart';
+import 'package:analyzer/src/plugin/plugin_impl.dart';
 import 'package:unittest/unittest.dart' hide ERROR;
 
 import '../analysis_abstract.dart';
 import '../reflective_tests.dart';
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(AssistsTest);
 }
 
@@ skipping 11 matching lines @@
         new EditGetAssistsParams(testFile, offset, length).toRequest('0');
     Response response = handleSuccessfulRequest(request);
     var result = new EditGetAssistsResult.fromResponse(response);
     changes = result.assists;
   }
 
   @override
   void setUp() {
     super.setUp();
     createProject();
-    handler = new EditDomainHandler(server);
+    ExtensionManager manager = new ExtensionManager();
+    ServerPlugin plugin = new ServerPlugin();
+    manager.processPlugins([plugin]);
+    handler = new EditDomainHandler(server, plugin);
   }
 
   Future test_removeTypeAnnotation() {
     addTestFile('''
 main() {
   int v = 1;
 }
 ''');
     return waitForTasksFinished().then((_) {
       prepareAssists('v =');
@@ skipping 49 matching lines @@
       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'));
   }
 }