NSubstitute和统一

Question

我目前正在学习DI & Mocking，使用Unity和NSubstitute。我还使用了一个取自这个问题的自动锁定扩展：Is this possible with Unity (Instead of Castle Windsor)?

在下面的单元测试中，我尝试从我的方法Add()中设置一个NSubstitute返回值10。但是，当通过控制器调用进行调试时，分配的值是默认值0，而不是预期的10。代理似乎没有截获方法调用。

我怀疑这是因为没有正确注册我的类型/容器，有谁能给我指出正确的方向吗？

[TestFixture]
public class ApplicationControllerTests
{
    private IUnityContainer _container;
    private ApplicationController _controller;
    private ISampleService _sampleService;

    [SetUp]
    public void SetUp()
    {
        _container = new UnityContainer().AddExtension(new AutoMockingContainerExtension());
        _controller = _container.Resolve<ApplicationController>();
        _sampleService = _container.Resolve<ISampleService>();
    }

    [Test]
    public void TestSampleService()
    {
        // This line is not working
        _sampleService.Add(Arg.Any<int>(), Arg.Any<int>()).Returns(10);

        var result = _controller.Index();

        _sampleService.Received().Add(Arg.Any<int>(), Arg.Any<int>());
    }
}

public class AutoMockingContainerExtension : UnityContainerExtension
{
    protected override void Initialize()
    {
        var strategy = new AutoMockingBuilderStrategy(Container);

        Context.Strategies.Add(strategy, UnityBuildStage.PreCreation);
    }

    class AutoMockingBuilderStrategy : BuilderStrategy
    {
        private readonly IUnityContainer _container;

        public AutoMockingBuilderStrategy(IUnityContainer container)
        {
            _container = container;
        }

        public override void PreBuildUp(IBuilderContext context)
        {
            var key = context.OriginalBuildKey;

            if (key.Type.IsInterface && !_container.IsRegistered(key.Type))
                context.Existing = CreateSubstitute(key.Type);
        }

        private static object CreateSubstitute(Type type)
        {
            return Substitute.For(new[] { type }, null);
        }
    }
}

和我的控制器代码

public class ApplicationController : BaseController
{
    private readonly ISampleService _sampleService;

    public ApplicationController(ISampleService sampleService)
    {
        _sampleService = sampleService;
    }

    public ActionResult Index()
    {
        var result = _sampleService.Add(2, 3);

        // result is 0, expected 10 ??

        return View();
    }
}

public interface ISampleService
{
    int Add(int first, int second);
}

public class SampleService : ISampleService
{
    public int Add(int first, int second)
    {
        return first + second;
    }
}

Answer 1

实际上，Tormod是对的，问题是每当有人从容器中请求一个时，AutoMockingBuilderStrategy 都会返回一个不同的模拟实例。

所以在我的original implementation中有一个bug，即AutoMockingBuilderStrategy没有存储创建的模拟：

下面是一个固定的版本：

public class AutoMockingContainerExtension : UnityContainerExtension
{
    protected override void Initialize()
    {
        var strategy = new AutoMockingBuilderStrategy(Container);

        Context.Strategies.Add(strategy, UnityBuildStage.PreCreation);
    }

    class AutoMockingBuilderStrategy : BuilderStrategy
    {
        private readonly IUnityContainer container;
        private readonly Dictionary<Type, object> substitutes 
           = new Dictionary<Type, object>();

        public AutoMockingBuilderStrategy(IUnityContainer container)
        {
            this.container = container;
        }

        public override void PreBuildUp(IBuilderContext context)
        {
            var key = context.OriginalBuildKey;

            if (key.Type.IsInterface && !container.IsRegistered(key.Type))
            {
                context.Existing = GetOrCreateSubstitute(key.Type);
                context.BuildComplete = true;
            }
        }

        private object GetOrCreateSubstitute(Type type)
        {
            if (substitutes.ContainsKey(type))
                return substitutes[type];

            var substitute = Substitute.For(new[] {type}, null);

            substitutes.Add(type, substitute);

            return substitute;
        }
    }
}

Answer 2

我怀疑您正在处理两个不同的ISampleService实例，它们分别在设置的第2行和第3行创建。为了进行测试，您可以将_sampleServie字段设置为公共字段，然后在第三行Setup()中尝试

_sampleService = _controller._sampleService;