Extract constants into separate libarary.

pkg/analysis_server/test/domain_server_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.domain.server;
 
 import 'package:analysis_server/src/analysis_server.dart';
+import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_server.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/resource.dart';
 import 'package:unittest/unittest.dart';
 
 import 'mocks.dart';
 
 main() {
   AnalysisServer server;
   ServerDomainHandler handler;
 
   setUp(() {
     var serverChannel = new MockServerChannel();
     var resourceProvider = PhysicalResourceProvider.INSTANCE;
     server = new AnalysisServer(serverChannel, resourceProvider);
     handler = new ServerDomainHandler(server);
   });
 
   group('ServerDomainHandler', () {
     test('getVersion', () {
-      var request = new Request('0', ServerDomainHandler.GET_VERSION_METHOD);
+      var request = new Request('0', METHOD_GET_VERSION);
       var response = handler.handleRequest(request);
       expect(response.toJson(), equals({
         Response.ID: '0',
         Response.RESULT: {
-          ServerDomainHandler.VERSION_RESULT: '0.0.1'
+          VERSION: '0.0.1'
         }
       }));
     });
 
     group('setSubscriptions', () {
       Request request;
       setUp(() {
-        request = new Request('0', ServerDomainHandler.SET_SUBSCRIPTIONS_METHOD);
+        request = new Request('0', METHOD_SET_SUBSCRIPTIONS);
       });
 
       test('invalid service name', () {
         request.setParameter(
-            ServerDomainHandler.SUBSCRIPTIONS_PARAMETER,
+            SUBSCRIPTIONS,
             ['noSuchService']);
         var response = handler.handleRequest(request);
         expect(response, isResponseFailure('0'));
       });
 
       test('success', () {
         expect(server.serverServices, isEmpty);
         // send request
         request.setParameter(
-            ServerDomainHandler.SUBSCRIPTIONS_PARAMETER,
+            SUBSCRIPTIONS,
             [ServerService.STATUS.name]);
         var response = handler.handleRequest(request);
         expect(response, isResponseSuccess('0'));
         // set of services has been changed
         expect(server.serverServices, contains(ServerService.STATUS));
       });
     });
 
     test('shutdown', () {
       expect(server.running, isTrue);
       // send request
-      var request = new Request('0', ServerDomainHandler.SHUTDOWN_METHOD);
+      var request = new Request('0', METHOD_SHUTDOWN);
       var response = handler.handleRequest(request);
       expect(response, isResponseSuccess('0'));
       // server is down
       expect(server.running, isFalse);
     });
   });
 }