update channel test per comments

pkg/analysis_server/test/channel_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.channel;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/channel.dart';
 import 'package:analysis_server/src/protocol.dart';
@@ skipping 43 matching lines @@
   }
 
   static Future close() {
     var timeout = new Duration(seconds: 1);
     var future = client.responseStream.drain().timeout(timeout);
     client.close();
     return future;
   }
 
   static Future invalidJsonToClient() {
-    socket.twin.add('{"foo":"bar"}');
-    server.sendResponse(new Response('myId'));
-    return client.responseStream
+    var result = client.responseStream
         .first
         .timeout(new Duration(seconds: 1))
         .then((Response response) {
           expect(response.id, equals('myId'));
           expectMsgCount(responseCount: 1);
         });
+    socket.twin.add('{"foo":"bar"}');
+    server.sendResponse(new Response('myId'));
+    return result;
   }
 
   static Future invalidJsonToServer() {
-    socket.add('"blat"');
-    return client.responseStream
+    var result = client.responseStream
         .first
         .timeout(new Duration(seconds: 1))
         .then((Response response) {
           expect(response.id, equals(''));
           expect(response.error, isNotNull);
           expectMsgCount(responseCount: 1);
         });
+    socket.add('"blat"');
+    return result;
   }
 
   static Future notification() {
-    server.sendNotification(new Notification('myEvent'));
-    return client.notificationStream
+    var result = client.notificationStream
         .first
         .timeout(new Duration(seconds: 1))
         .then((Notification notification) {
           expect(notification.event, equals('myEvent'));
           expectMsgCount(notificationCount: 1);
-
           expect(notificationsReceived.first, equals(notification));
         });
+    server.sendNotification(new Notification('myEvent'));
+    return result;
   }
 
   static Future notificationAndResponse() {
-    server
-        ..sendNotification(new Notification('myEvent'))
-        ..sendResponse(new Response('myId'));
-    return Future
+    var result = Future
         .wait([
           client.notificationStream.first,
           client.responseStream.first])
         .timeout(new Duration(seconds: 1))
         .then((_) => expectMsgCount(responseCount: 1, notificationCount: 1));
+    server
+        ..sendNotification(new Notification('myEvent'))
+        ..sendResponse(new Response('myId'));
+    return result;
   }
 
   static void request() {
     client.sendRequest(new Request('myId', 'myMth'));
     server.listen((Request request) {
       expect(request.id, equals('myId'));
       expect(request.method, equals('myMth'));
       expectMsgCount(requestCount: 1);
     });
   }
@@ skipping 28 matching lines @@
   }
 
   static void expectMsgCount({requestCount: 0,
                               responseCount: 0,
                               notificationCount: 0}) {
     expect(requestsReceived, hasLength(requestCount));
     expect(responsesReceived, hasLength(responseCount));
     expect(notificationsReceived, hasLength(notificationCount));
   }
 }