Async unittesting with Dart on the server side

asynctest.dart

test("Channel, joining/leaving, fires event", () {
  User u = TestFactory.getTestUser(userId, ws);
  MockChannelConnectionEventListener l = new MockChannelConnectionEventListener();
  c.subscribe(l);
  bool wasJoined = false;
  bool wasLeft = false;
  
  l.joinCallback = (Channel chan, User user) {
    expect(chan, equals(c));
    expect(user, equals(u));
    wasJoined = true;
  };
  
  l.leaveCallback = (Channel chan, User user) {
    expect(chan, equals(c));
    expect(user, equals(u));
    wasLeft = true;
  };
  
  c.join(u);
  c.leave(u);
  
  Timer t = new Timer(100, (_) {
    expect(wasJoined, equals(true));
    expect(wasLeft, equals(true));
  });
  
});