c# - 使用 Moq 模拟单元测试中的执行延迟

Question

我正在尝试测试以下内容:

protected IHealthStatus VerifyMessage(ISubscriber destination)
{
    var status = new HeartBeatStatus();

    var task = new Task<CheckResult>(() =>
    {
        Console.WriteLine("VerifyMessage(Start): {0} - {1}", DateTime.Now, WarningTimeout);
        Thread.Sleep(WarningTimeout - 500);
        Console.WriteLine("VerifyMessage(Success): {0}", DateTime.Now);
        if (CheckMessages(destination))
        {
            return CheckResult.Success;
        }

        Console.WriteLine("VerifyMessage(Pre-Warning): {0} - {1}", DateTime.Now, ErrorTimeout);
        Thread.Sleep(ErrorTimeout - 500);
        Console.WriteLine("VerifyMessage(Warning): {0}", DateTime.Now);
        if (CheckMessages(destination))
        {
            return CheckResult.Warning;
        }

        return CheckResult.Error;
    });

    task.Start();

    task.Wait();
    status.Status = task.Result;

    return status;
}

使用以下单元测试:

public void HeartBeat_Should_ReturnWarning_When_MockReturnsWarning()
{
    // Arrange
    var heartbeat = new SocketToSocketHeartbeat(_sourceSubscriber.Object, _destinationSubscriber.Object);
    heartbeat.SetTaskConfiguration(this.ConfigurationHB1ToHB2_ValidConfiguration());

    // Simulate the message being delayed to destination subscriber.
    _destinationSubscriber.Setup(foo => foo.ReceivedMessages).Returns(DelayDelivery(3000, Message_HB1ToHB2()));

    // Act
    var healthStatus = heartbeat.Execute();

    // Assert
    Assert.AreEqual(CheckResult.Warning, healthStatus.Status);
}

Message_HB1ToHB2()只是返回一串字符，“Delay Delivery”方法是

private List<NcsMessage> DelayDelivery(int delay, string message)
{
    var sent = DateTime.Now;
    var msg = new NcsMessage()
    {
        SourceSubscriber = "HB1",
        DestinationSubscriber = "HB2",
        SentOrReceived = sent,
        Message = message
    };

    var messages = new List<NcsMessage>();
    messages.Add(msg);

    Console.WriteLine("DelayDelivery: {0}", DateTime.Now);
    Thread.Sleep(delay);
    Console.WriteLine("DelayDelivery: {0}", DateTime.Now);

    return messages;
}

我使用 Moq 作为模拟框架，使用 MSTest 作为测试框架。每当我运行单元测试时，我都会得到以下输出:

DelayDelivery: 04/04/2013 15:50:33
DelayDelivery: 04/04/2013 15:50:36
VerifyMessage(Start): 04/04/2013 15:50:36 - 3000
VerifyMessage(Success): 04/04/2013 15:50:38

除了在上述方法中使用 Thread.Sleep 的明显“代码味道”之外，单元测试的结果并不是我想要完成的。

任何人都可以建议一种更好/准确的方法来使用 Moq 框架来模拟消息“传递”的延迟。我省略了一些“胶水”代码，只包含了相关部分。如果我遗漏了一些妨碍您理解问题的内容，请告诉我。

Answer 1

如果您希望 Moq 模拟只是坐下一段时间什么都不做，您可以使用回调:

Mock<IFoo> mockFoo = new Mock<IFoo>();
mockFoo.Setup(f => f.Bar())
       .Callback(() => Thread.Sleep(1000))
       .Returns("test");

string result = mockFoo.Object.Bar(); // will take 1 second to return

Assert.AreEqual("test", result);

我已经在 LinqPad 中尝试过，如果您调整 Thread.Sleep()，执行时间会相应变化。