c# – 我如何模拟这个异步方法？

我有一个类似于这样的类：

public class viewmodel
{
  public viewmodel(IWebService service)
  {
    this.WebService = service;
  }

  private IWebService WebService{get;set;}  
  private IEnumerable<SomeData> MyData{get;set;}

  private void GetReferenceData()
  {
    this.WebService.BeginGetStaticReferenceData(GetReferenceDataOnComplete,null);
  }

  private void GetReferenceDataOnComplete(IAsyncResult result)
  {
    this.MyData = this.WebService.EndGetStaticReferenceData(result);
  }
  .
  .
  .
}

我想嘲笑我的IWebService接口,以便在调用BeginGetStaticReferenceData时可以调用回调方法.我正在使用Moq,我无法解决如何做到这一点.我的单元测试设置代码看起来像：

//Arrange
var service = new Mock<IWebService>();
service.Setup(x => x.BeginGetStaticReferenceData(/*.......don't kNow.....*/));
service.Setup(x => x.EndGetStaticReferenceData(It.IsAny<IAsyncResult>())).Returns(new List<SomeData>{new SomeData{Name="blah"}});
var viewmodel = new viewmodel(service.Object);
.
.

解决方法

就是这样：

[TestMethod]
public void Test10()
{
    var expectedData = new[]{new SomeData(),new SomeData()};

    AsyncCallback callback = null;
    IAsyncResult ar = new Mock<IAsyncResult>().Object;

    var webServiceStub = new Mock<IWebService>();
    webServiceStub
        .Setup(ws => ws.BeginGetStaticReferenceData(It.IsAny<AsyncCallback>(),null))
        .Callback((AsyncCallback cb,object state) => callback = cb)
        .Returns(ar);
    webServiceStub
        .Setup(ws => ws.EndGetStaticReferenceData(It.IsAny<IAsyncResult>()))
        .Returns(expectedData);

    var sut = new viewmodel(webServiceStub.Object);
    sut.DoIt();

    callback(ar);

    Assert.AreEqual(expectedData,sut.MyData);
}

这个测试假定了一个稍微修改的viewmodel,我添加了几个公共成员来测试一些东西：

public class viewmodel
{
    public viewmodel(IWebService service)
    {
        this.WebService = service;
    }

    public IEnumerable<SomeData> MyData { get; set; }

    public void DoIt()
    {
        this.GetReferenceData();
    }

    private IWebService WebService { get; set; }

    private void GetReferenceData()
    {
        this.WebService.BeginGetStaticReferenceData(GetReferenceDataOnComplete,null);
    }

    private void GetReferenceDataOnComplete(IAsyncResult result)
    {
        this.MyData = this.WebService.EndGetStaticReferenceData(result);
    }
}