Use pumpEventQueue() from test (flutter#12)

Author: nex3

pubspec.yaml

@@ -1,5 +1,5 @@
 name: stream_channel
-version: 1.6.2
+version: 1.6.3-dev
 description: An abstraction for two-way communication channels.
 author: Dart Team <[email protected]>
 homepage: https://github.com/dart-lang/stream_channel
@@ -9,4 +9,4 @@ dependencies:
   async: '>=1.11.0 <3.0.0'
   stack_trace: '^1.0.0'
 dev_dependencies:
-  test: '^0.12.18'
+  test: '^0.12.28'

test/disconnector_test.dart

@@ -8,8 +8,6 @@ import 'package:async/async.dart';
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 void main() {
   var streamController;
   var sinkController;

test/isolate_channel_test.dart

@@ -8,8 +8,6 @@ import 'dart:isolate';
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 void main() {
   var receivePort;
   var sendPort;

test/multi_channel_test.dart

@@ -5,8 +5,6 @@
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 void main() {
   var controller;
   var channel1;

test/stream_channel_completer_test.dart

@@ -7,8 +7,6 @@ import 'dart:async';
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 void main() {
   var completer;
   var streamController;

test/utils.dart

@@ -8,8 +8,6 @@ import 'package:async/async.dart';
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 final _delayTransformer = new StreamTransformer.fromHandlers(
     handleData: (data, sink) => new Future.microtask(() => sink.add(data)),
     handleDone: (sink) => new Future.microtask(() => sink.close()));

test/with_close_guarantee_test.dart

@@ -7,8 +7,6 @@ import 'dart:async';
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
-import 'utils.dart';
-
 void main() {
   var streamController;
   var sinkController;