Add IsolateChannel.connect* constructors.

test/isolate_channel_test.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:async';
 import 'dart:isolate';
 
 import 'package:stream_channel/stream_channel.dart';
 import 'package:test/test.dart';
 
@@ skipping 105 matching lines @@
       controller.addError("oh no");
       expect(channel.sink.done, throwsA("oh no"));
       await pumpEventQueue();
       expect(canceled, isTrue);
 
       // Even though the sink is closed, this shouldn't throw an error because
       // the user didn't explicitly close it.
       channel.sink.add(1);
     });
   });
+
+  group("connect constructors", () {
+    var connectPort;
+    setUp(() {
+      connectPort = new ReceivePort();
+    });
+
+    tearDown(() {
+      connectPort.close();
+    });
+
+    test("create a connected pair of channels", () {
+      var channel1 = new IsolateChannel.connectReceive(connectPort);
+      var channel2 = new IsolateChannel.connectSend(connectPort.sendPort);
+
+      channel1.sink.add(1);
+      channel1.sink.add(2);
+      channel1.sink.add(3);
+      expect(channel2.stream.take(3).toList(), completion(equals([1, 2, 3])));
+
+      channel2.sink.add(4);
+      channel2.sink.add(5);
+      channel2.sink.add(6);
+      expect(channel1.stream.take(3).toList(), completion(equals([4, 5, 6])));
+    });
+
+    test("the receiving channel produces an error if it gets the wrong message",
+        () {
+      var connectedChannel = new IsolateChannel.connectReceive(connectPort);
+      connectPort.sendPort.send("wrong value");
+
+      expect(connectedChannel.stream.toList(), throwsStateError);
+      expect(connectedChannel.sink.done, completes);
+    });
+  });
 }