AutoFixture：模拟方法不返回冻结实例

我正在尝试编写这个简单的测试：

var fixture = new Fixture().Customize(new AutoMoqCustomization());

var postProcessingAction = fixture.Freeze<Mock<IPostProcessingAction>>();
var postProcessor = fixture.Freeze<PostProcessor>();

postProcessor.Process("", "");

postProcessingAction.Verify(action => action.Do());

The Verify检查失败。
postProcessor.Process 的代码是

public void Process(string resultFilePath, string jobId)
{
    IPostProcessingAction postProcessingAction =
        postProcessingActionReader
            .CreatePostProcessingActionFromJobResultXml(resultFilePath);

    postProcessingAction.Do();
}

postProcessingActionReader是通过构造函数初始化的接口字段。

我期望测试能够通过，但它失败了，事实证明是IPostProessingAction从返回的CreatePostProcessingActionFromJobResultXml方法与返回的实例不同fixture.Freeze<>.

我的期望是，在冻结这个 Mock 对象后，它会注入底层的模拟IPostProcessingAction在每个需要的地方提供接口，并使所有模拟方法返回IPostProcessingAction返回同一个对象。

我对模拟方法的返回值的期望是否不正确？ 有没有办法改变这种行为，以便模拟方法返回相同的冻结实例？

你需要Freeze the IPostProcessingActionReader成分。

以下测试将通过：

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

    var postProcessingActionMock = new Mock<IPostProcessingAction>();

    var postProcessingActionReaderMock = fixture
        .Freeze<Mock<IPostProcessingActionReader>>();

    postProcessingActionReaderMock
        .Setup(x => x.CreatePostProcessingActionFromJobResultXml(
            It.IsAny<string>()))
        .Returns(postProcessingActionMock.Object);

    var postProcessor = fixture.CreateAnonymous<PostProcessor>();
    postProcessor.Process("", "");

    postProcessingActionMock.Verify(action => action.Do());
}

假设类型定义为：

public interface IPostProcessingAction
{
    void Do();
}

public class PostProcessor
{
    private readonly IPostProcessingActionReader actionReader;

    public PostProcessor(IPostProcessingActionReader actionReader)
    {
        if (actionReader == null)
            throw new ArgumentNullException("actionReader");

        this.actionReader = actionReader;
    }

    public void Process(string resultFilePath, string jobId)
    {
        IPostProcessingAction postProcessingAction = this.actionReader
            .CreatePostProcessingActionFromJobResultXml(resultFilePath);

        postProcessingAction.Do();
    }
}

public interface IPostProcessingActionReader
{
    IPostProcessingAction CreatePostProcessingActionFromJobResultXml(
        string resultFilePath);
}

如果您使用 AutoFixture声明式地与 xUnit.net扩大测试可以进一步简化：

[Theory, AutoMoqData]
public void Test(
    [Frozen]Mock<IPostProcessingActionReader> readerMock,
    Mock<IPostProcessingAction> postProcessingActionMock,
    PostProcessor postProcessor)
{
    readerMock
        .Setup(x => x.CreatePostProcessingActionFromJobResultXml(
            It.IsAny<string>()))
        .Returns(postProcessingActionMock.Object);

    postProcessor.Process("", "");

    postProcessingActionMock.Verify(action => action.Do());
}

The AutoMoqDataAttribute定义为：

internal class AutoMoqDataAttribute : AutoDataAttribute
{
    internal AutoMoqDataAttribute()
        : base(new Fixture().Customize(new AutoMoqCustomization()))
    {
    }
}