我的Mocked DbContext使用Moq在单元测试中写入db

Question

我是嘲笑和使用Moq的新手.这是我第一次尝试模拟添加功能.我有mocks设置,它适用于读取功能,但是当我尝试对add方法进行单元测试时,它会将更改保存到db.

如何模拟add方法？

我想我必须模拟我的UnitOfWork班级,这个班级有这个SaveChanges()方法.我想知道如何设置模拟来拦截调用SaveChanges()而不是保存到db.

这是我到目前为止的模拟

[SetUp]
    public void SetUp()
    {
        addCount = 0;

        IEnumerable<Platform> platformList = new List<Platform>(){
            new Platform() { Id = 1, Name = "Unknown"},
            new Platform() { Id =2, Name = "Amazon"},
            new Platform() { Id = 3, Name = "Prime Pantry"}
        };
        var platformData = platformList.AsQueryable();

        var mockPlatformSet = new Mock<DbSet<Platform>>();
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.Provider).Returns(platformData.Provider);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.Expression).Returns(platformData.Expression);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.ElementType).Returns(platformData.ElementType);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.GetEnumerator()).Returns(platformData.GetEnumerator());
        mockPlatformSet.Setup(m => m.Add(It.IsAny<Platform>())).Callback(() => addCount++);

        var mockContext = new Mock<ApplicationDbContext>(){ CallBase = true };
        mockContext.Setup(m => m.Platforms).Returns(mockPlatformSet.Object);
        mockContext.Setup(m => m.Platforms.Add(It.IsAny<Platform>()));
        mockContext.Setup(m => m.Platforms.Add(It.IsAny<Platform>())).Callback(() => addCount++);


        unitOfWork = new UnitOfWork(mockContext.Object);
        platformRepo = new PlatformRepository(mockContext.Object);

        controller = new PlatformController(platformRepo, unitOfWork);
    }

添加UnitOfWork代码

public class UnitOfWork : IUnitOfWork 
{
    private readonly DbContext _context;
    private bool _isDisposed = false;

    public UnitOfWork(DbContext context)
    {
        _context = context;
    }

    public void SaveChanges()
    {
        _context.SaveChanges();
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!_isDisposed)
        {
            if (disposing)
            {
                _context.Dispose();
            }
        }
        _isDisposed = true;
    }

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

}

更新的问题

我正在尝试对我的Create方法进行单元测试PlatformController.在这个方法中,我Add在repostiory上调用函数然后调用SaveChanges函数UnitOfWork.我想验证我的Platform对象是否被添加到DbSet,但是"拦截"调用SaveChanges()它不会写入db.

我怎样才能做到这一点？

Answer 1

当我设置了CallBase我的价值mockContext作为IUnitOfWork对false,这似乎已经解决了我的单元测试写入到数据库的问题.

这行代码: mockContext.As<IUnitOfWork>().CallBase = false;

这是我的Setup功能代码

[SetUp]
    public void SetUp()
    {
        addCount = 0;

        IEnumerable<Platform> platformList = new List<Platform>(){
            new Platform() { Id = 1, Name = "Unknown"},
            new Platform() { Id =2, Name = "Amazon"},
            new Platform() { Id = 3, Name = "Prime Pantry"}
        };
        var platformData = platformList.AsQueryable();

        var mockPlatformSet = new Mock<DbSet<Platform>>();
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.Provider).Returns(platformData.Provider);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.Expression).Returns(platformData.Expression);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.ElementType).Returns(platformData.ElementType);
        mockPlatformSet.As<IQueryable<Platform>>().Setup(m => m.GetEnumerator()).Returns(platformData.GetEnumerator());
        mockPlatformSet.Setup(m => m.Add(It.IsAny<Platform>())).Callback(() => addCount++);

        var mockContext = new Mock<ApplicationDbContext>(){ CallBase = true };
        mockContext.Setup(m => m.Platforms).Returns(mockPlatformSet.Object);
        mockContext.Setup(m => m.Platforms.Add(It.IsAny<Platform>()));
        mockContext.Setup(m => m.Platforms.Add(It.IsAny<Platform>())).Callback(() => addCount++);
        mockContext.Setup(m => m.Set<Platform>()).Returns(mockPlatformSet.Object);
        mockContext.As<IUnitOfWork>().CallBase = false;

        unitOfWork = new UnitOfWork(mockContext.Object);
        platformRepo = new PlatformRepository(mockContext.Object);

        controller = new PlatformController(platformRepo, unitOfWork);
    }