模拟更改的getResponse .net

Question

我有一个测试，从端点获取一些设备状态。我的反应被嘲弄了，得到了正确的信息。我想要实现的测试必须得到这个信息，过一段时间再得到这个信息，并检查抛出一个事件是否不同。问题是我不能在我的测试中更改被模仿的响应。这就是我试过的。

模拟WebRequest的实现。

class TestWebRequestCreate : IWebRequestCreate
{

    public TestWebRequest testWebRequest { get; set; }

    public WebRequest Create(Uri uri)
    {
        WebRequest webRequest;
        if (testWebRequest == null)
        {
            webRequest = new TestWebRequest(HttpStatusCode.OK, "Testing response");
        }
        else
        {
            webRequest = testWebRequest;
        }
        return webRequest;
    }
}

class TestWebRequest : WebRequest
{
    public HttpStatusCode httpStatusCode { get; set; }
    public Stream responseMessage;

    /// <summary>
    ///  Initialize a new instance of <see cref="TestWebRequest"/>
    ///  with the response to return
    /// </summary>
    public TestWebRequest(HttpStatusCode httpStatusCode, string responseMessage)
    {
        this.httpStatusCode = httpStatusCode;
        this.responseMessage = StreamFromString(responseMessage);

    }

    public override WebResponse GetResponse()
    {
        MemoryStream responseCopy = new MemoryStream();
        //Stream responseCopy = new MemoryStream();
        responseMessage.Position = 0;
        responseMessage.CopyTo(responseCopy);
        //Reset position after reading Streams
        responseCopy.Position = 0;
        Mock<HttpWebResponse> mockHttpWebResponse = new Mock<HttpWebResponse>();
        mockHttpWebResponse.Setup(r => r.StatusCode).Returns(httpStatusCode);
        mockHttpWebResponse.Setup(r => r.GetResponseStream()).Returns(responseCopy);
        return mockHttpWebResponse.Object;
    }  

在我的测试中，我做了这个：

        public void DeviceChangedEvent_WhenDeviceHaveChanged_EventIsThrown()
    {
        string uri = new UriBuilder(TESTHOSTPREFFIX, TESTCORRECTHOST, TESTPORT, TESTDEVICEENDPOINT).ToString();
        bool wasThrown = false;
        m_deviceRetriever.Init(m_serviceProvider);
        m_deviceRetriever.Start();
        m_deviceRetriever.DeviceChangeEvent += (DeviceRetrieverOnDeviceChangeEvent, args) =>
        {
            wasThrown = true;
        };

        Thread.Sleep(5000);

        //Change device XML to simulate the change
        var namespaceManager = new XmlNamespaceManager(m_correctMockedXmlDevice.NameTable);
        namespaceManager.AddNamespace("ps", "http://www.hp.com/ps/fall15");
        XmlNode printheadIdNode = m_correctMockedXmlDevices.SelectSingleNode("/ps:DevicesStatus/DeviceSlotCollection/DeviceSlot/SlotId", namespaceManager);
        deviceIdNode.InnerText = "Changed";
        m_testWebRequestCreateCorrectDevices = null;
        m_testWebRequestCreateCorrectDevices = new TestWebRequestCreate
        {
            testWebRequest = new TestWebRequest(HttpStatusCode.OK, m_correctMockedXmlDevices.InnerXml)
        };

        Thread.Sleep(5000);

        //We give some time to get the new state of printheads
        Assert.IsTrue(wasThrown);
    }
}

在测试之前，我正在准备创建以下内容

    private void CreateCorrectDevicesMockEndpoint()
    {
        string uri = new UriBuilder(TESTHOSTPREFFIX, TESTCORRECTHOST, TESTPORT, TESTPRINTHEADSENDPOINT).ToString();
        m_testWebRequestCreateCorrectDevices = new TestWebRequestCreate();
        m_correctMockedXmlDevices = new XmlDocument();
        m_correctMockedXmlDevices.Load("pathToXMLFile");
        m_testWebRequestCreateCorrectDevices.testWebRequest = new TestWebRequest(HttpStatusCode.OK, m_correctMockedXmlPrintheads.InnerXml);
        WebRequest.RegisterPrefix(uri, m_testWebRequestCreateCorrectDevices);
    }

编辑:我的测试设置是初始化所有必要的依赖项。

    public void SetUp()
    {
        m_serviceProvider = new ServiceProvider();

        m_serviceProvider.Add<ILogger>(new Mock<ILogger>().Object);

        m_deviceRetriever = new DeviceRetriever();

        m_connectivitySettings = new ConnectivitySettings() { IpAddress = TESTCORRECTHOST };
        m_serviceProvider.Add<ConnectivitySettings>(m_connectivitySettings);

        CreateCorrectDevicesMockEndpoint();
    }

我没有收到任何错误，问题是我的模拟返回的XML没有被更改。谢谢你的帮助!

Answer 1

正如我在我的评论中所说的，我相信您的问题在于您没有向我们展示的代码。您正在设置的模拟很好，但是它依赖于您在正确的TestWebRequest实例上调用TestWebRequest。我相信，不管您是在轮询，您没有更新计票程序正在使用的TestWebRequestCreate实例，因此它只是创建了带有原始模拟的TestWebRequest设置的另一个实例。下面是一个示例，完整的测试，说明您的模拟工作，可以从一个不同的线程和工作的预期访问。

bool wasThrown = false;
IWebRequestCreate m_testWebRequestCreateCorrectDevices = null;

[TestMethod]
public void TestThreadedWebRequest()
{
    const string errorResponse = "Some Error Text";
    m_testWebRequestCreateCorrectDevices = new TestWebRequestCreate();
    var uri = new Uri(@"http:\\www.stackoverflow.com");
    wasThrown = false;

    var thread = new System.Threading.Thread(() =>
        {
            while (true)
            {
                var creator = m_testWebRequestCreateCorrectDevices;
                if (creator != null)
                {
                    var message = creator.Create(uri); 
                    var response = new StreamReader(message.GetResponse()
                                                      .GetResponseStream()).ReadToEnd();
                    if (response == errorResponse)
                    {
                        wasThrown = true;
                        break;
                     }
                }
                System.Threading.Thread.Sleep(500);
            }
        });

    thread.Start();

    System.Threading.Thread.Sleep(5000);
    Assert.AreEqual(false, wasThrown);


    m_testWebRequestCreateCorrectDevices = null;
    m_testWebRequestCreateCorrectDevices = new TestWebRequestCreate
    {
        testWebRequest = new TestWebRequest(HttpStatusCode.OK, errorResponse)
    };

    System.Threading.Thread.Sleep(5000);

    Assert.AreEqual(true, wasThrown);

    if (!thread.Join(1000))
    {
        thread.Abort();
    }
}

注意，在现有代码中，将m_testWebRequestCreateCorrectDevices设置为创建正确模拟响应的新消息创建者的实例。这是不可能的，除非您的生产代码引用了这个变量(在我上面的例子中就是这样)。