public void ChecksState() { m_coreLinkMock.Setup(link => link.Request(It.IsAny <GetStateConversation>(), It.IsAny <int>())).Returns( () => { var task = new Task <StateResponse>(() => new StateResponse()); task.Start(); return(task); }); var stateUpdatedEvent = new AutoResetEvent(false); m_controller.StartStateChecking(stateResponse => stateUpdatedEvent.Set()); Assert.True(stateUpdatedEvent.WaitOne(TimeoutMs)); }