c# - AutoFixture+Moq - 卡住模拟类以防止设置

Question

我想了解为什么当我卡住模拟类而不是模拟接口(interface)时我的测试失败

[Fact]
public void MethodeName()
{
    var fixture = new Fixture().Customize(new AutoMoqCustomization());

    var webRequestMock = fixture.Freeze<Mock<MyWebRequest>>(); // freezing a class + setuping a return value
    webRequestMock.Setup(a => a.GetData())
    .Returns("Foo");

    var myService = fixture.Create<MyService>();

    var actual = myService.GetData();

    webRequestMock.Verify(a => a.GetData(), Times.Once()); // Failed it's never called once
    Assert.Equal("Foo", actual); // Failed, if we comment previous line, 'actual' value is always empty
}

public class MyService
{
    private readonly MyWebRequest _request;

    public MyService(MyWebRequest request)
    {
        _request = request;
    }

    public string GetData()
    {
        var data = _request.GetData();
        return data;
    }
}

public class MyWebRequest 
{
    public virtual string GetData() // you can see here, the method is well virtual, and should be overridable by moq.
    {
        return string.Empty;
    }
}

1/ 如果我尝试使用模拟界面，它会起作用。

[Fact]
public void MethodeName()
{
    var fixture = new Fixture().Customize(new AutoMoqCustomization());
    const string expected = "Foo";

    var webRequestMock = fixture.Freeze<Mock<IMyWebRequest>>();
    webRequestMock.Setup(a => a.GetData())
    .Returns("Foo");

    var myService = fixture.Create<MyService>();

    var actual = myService.GetData();

    webRequestMock.Verify(a => a.GetData(), Times.Once()); // Success
    Assert.Equal(expected, actual); // Success
}

public class MyService
{
    private readonly IMyWebRequest _request;

    public MyService(IMyWebRequest request)
    {
        _request = request;
    }

    public string GetData()
    {
        var data = _request.GetData();
        return data;
    }
}

public interface IMyWebRequest
{
    string GetData();
}

public class MyWebRequest : IMyWebRequest
{
    public virtual string GetData()
    {
        return string.Empty;
    }
}

2/ 如果我使用“注入(inject)”而不是卡住，它会起作用:

[Fact]
public void MethodeName()
{
    var fixture = new Fixture().Customize(new AutoMoqCustomization());
    const string expected = "Foo";

    var webRequestMock = new Mock<MyWebRequest>(); 
    webRequestMock.Setup(a => a.GetData()).Returns("Foo");
    fixture.Inject(webRequestMock.Object);

    var myService = fixture.Create<MyService>();

    var actual = myService.GetData();

    webRequestMock.Verify(a => a.GetData(), Times.Once()); // Success
    Assert.Equal(expected, actual); // Success
}

public class MyService
{
    private readonly MyWebRequest _request;

    public MyService(MyWebRequest request)
    {
        _request = request;
    }

    public string GetData()
    {
        var data = _request.GetData();
        return data;
    }
}

public class MyWebRequest 
{
    public virtual string GetData()
    {
        // make WebRequest
        return string.Empty;
    }
}

我的自动修复版本:3.6.5.0

Answer 1

MyWebRequest 是一个具体的(非抽象的)类，AutoFixture.AutoMoq 不会使用 Moq 创建那些类。这是设计的，因为 AutoFixture 内核已经处理了“普通”类的创建。

You can change this behaviour如果你愿意的话。不过，我通常会考虑必须这样做是一种设计味道。不过，在这种情况下很难判断，因为您已经很好地将问题减少到最小程度。但是，问题在于，如此处所示，MyService 不会增加任何值。我确定这不是您的真实代码的样子，但由于我无法猜测您的真实代码的样子，所以我无法判断是否可以进行更好的设计。