asp.net-mvc - TDD 工作单元模式 Moq 无法实例化类错误代理

Question

我是测试驱动开发的新手，并尝试对 mvc 应用程序进行单元测试。我正在使用 Moq 和 Ninject，并尝试遵循工作单元存储库模式。我的所有测试都收到 System.ArgumentException 错误。这是错误消息和错误堆栈跟踪:

Test method LOMSv4.Tests.Controllers.AutobytelControllerTest.Index_Contains_All_Requests threw exception: 
System.ArgumentException: Can not instantiate proxy of class: LOMSv4_DAL.Autobytel.Concrete.RequestRepository.
Could not find a parameterless constructor.

参数名称:constructorArguments

Castle.DynamicProxy.ProxyGenerator.CreateClassProxyInstance(Type proxyType, List`1 proxyArguments, Type classToProxy, Object[] constructorArguments)
Castle.DynamicProxy.ProxyGenerator.CreateClassProxy(Type classToProxy, Type[] additionalInterfacesToProxy, ProxyGenerationOptions options, Object[] constructorArguments, IInterceptor[] interceptors)
Moq.Proxy.CastleProxyFactory.CreateProxy[T](ICallInterceptor interceptor, Type[] interfaces, Object[] arguments)
Moq.Mock`1.<InitializeInstance>b__0()
Moq.PexProtector.Invoke(Action action)
Moq.Mock`1.InitializeInstance()
Moq.Mock`1.OnGetObject()
Moq.Mock.GetObject()
Moq.Mock.get_Object()
Moq.MockDefaultValueProvider.ProvideDefault(MethodInfo member)
Moq.QueryableMockExtensions.FluentMock[T,TResult](Mock`1 mock, Expression`1 setup)
lambda_method(Closure )
Moq.Mock.GetInterceptor(Expression fluentExpression, Mock mock)
Moq.Mock.<>c__DisplayClass1c`2.<Setup>b__1b()
Moq.PexProtector.Invoke[T](Func`1 function)
Moq.Mock.Setup[T,TResult](Mock mock, Expression`1 expression, Func`1 condition)
Moq.Mock`1.Setup[TResult](Expression`1 expression)

这是我的测试类:

[TestClass]
public class AutobytelControllerTest
{
    Mock<IUnitOfWork> mock = new Mock<IUnitOfWork>();

    [TestMethod]
    public void Index_Contains_All_Requests()
    {
        //Arrange
        AutobytelController controller = new AutobytelController(mock.Object);
        mock.Setup(m => m.RequestRepository.SelectAll()).Returns(new abtRequest[] {
            new abtRequest {RequestID = 1, Title = "Request 1", Description = "Request Description1", UserName = "NewUser", RequestStatus = 0},
            new abtRequest {RequestID = 2, Title = "Request 2", Description = "Request Description2", UserName = "ReturnUser", RequestStatus = 1}
        }.AsQueryable());

        //Act
        abtRequest[] result = ((AutobytelHomeViewModel)controller.Index().Model).Requests.ToArray();
        //Assert
        Assert.AreEqual(result.Length, 2);
        Assert.AreEqual("Request 1", result[0].Title);
        Assert.AreEqual("Request 2", result[1].Title);
    }

我有一个 IUnitofWork 接口(interface)和类、通用存储库接口(interface)和类以及一个实现通用存储库的请求存储库

public interface IUnitOfWork
{
    RequestRepository RequestRepository { get; }
    void Save();
}

<小时/>

public class UnitOfWorkRepository : IUnitOfWork, IDisposable
{
    private AutobytelEntities context = new AutobytelEntities();
    private RequestRepository requestRepository;

    public RequestRepository RequestRepository
    {
        get
        {
            if (this.requestRepository == null)
            {
                //this.requestRepository = new GenericRepository<abtRequest>(context);
                this.requestRepository = new RequestRepository(context);
            }
            return requestRepository;
        }
    }

    public void Save()
    {
        context.SaveChanges();
    }

    private bool disposed = false;

    protected virtual void Dispose(bool disposing)
    {
        if (!this.disposed)
        {
            if (disposing)
            {
                context.Dispose();
            }
        }
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }
}

<小时/>

public class GenericRepository<TEntity> : IGenericRepository<TEntity> where TEntity : class
{
    internal AutobytelEntities context;
    internal IObjectSet<TEntity> objectSet;


    public GenericRepository(AutobytelEntities context)
    {
        this.context = context;
        this.objectSet = context.CreateObjectSet<TEntity>();
    }

    public virtual IQueryable<TEntity> SelectAll()
    {
        return objectSet.AsQueryable();
    }

    public virtual TEntity Update(TEntity entity)
    {
        context.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);
        return entity;
    }

    public virtual void Delete(TEntity entity)
    {
        objectSet.DeleteObject(entity);
    }
}

<小时/>

    public class RequestRepository : GenericRepository<abtRequest>, IGenericRepository<abtRequest>
{
    public RequestRepository(AutobytelEntities context) : base(context)
    { }

    public virtual abtRequest SelectByUserName(string username)
    {
        return context.abtRequests.FirstOrDefault(i => i.UserName == username && (i.RequestStatus == 0 || i.RequestStatus == 1));
    }

    public virtual abtRequest SelectByRequestID(int requestID)
    {
        return context.abtRequests.FirstOrDefault(i => i.RequestID == requestID);
    }

使用 Ninject，我将 IUnitofwork 绑定(bind)到 UnitOfWork 类。

如果我向请求存储库添加无参数构造函数，我的错误就会解决 - 但因为我不想创建新的对象上下文，所以我想从工作单元存储库传递我的上下文。

如何解决此错误？

Answer 1

我通过向 RequestRepository 添加接口(interface)并在我的工作单元中创建该接口(interface)的实例来解决此错误。我的 IUnit of Work 更改为:

public interface IUnitOfWork
{
    IRequestRepository RequestRepository { get; }
    void Save();
}

在我的 UnitOfWork 存储库中更改为:

private IRequestRepository requestRepository;

public IRequestRepository RequestRepository
{
    get
    {
        if (this.requestRepository == null)
        {
            this.requestRepository = new RequestRepository(context);
        }
        return requestRepository;
    }
}