如何模拟存储库/工作单元 [英] How to mock Repository/Unit Of Work

问题描述

在我的应用程序中，我具有通过UnitOfWork连接到控制器的通用存储库.我想对我的应用进行单元测试.为此，我需要模拟数据库连接. 你能告诉我该怎么办吗?模拟回购?模拟回购和UnitOfWork?我将不胜感激任何代码段/建议. 这是我的仓库:

In my app I have generic repository connected to controller through UnitOfWork. I want to unit test my app. To make this I need to mock db connection. Can you tell me what should do? Mock repo? Mock repo and UnitOfWork? I'll be gratefull for any code snippets/suggestions. Here my Repo:

public class GenericRepository<TEntity> where TEntity : class
{
    internal EquipmentEntities context;
    internal DbSet<TEntity> dbSet;

    public GenericRepository(EquipmentEntities context)
    {
        this.context = context;
        this.dbSet = context.Set<TEntity>();
    }

    public virtual IEnumerable<TEntity> Get(
        List<Expression<Func<TEntity, bool>>> filter,
        Func<IQueryable<TEntity>, IOrderedQueryable<TEntity>> orderBy = null,
        int? Page=0,
        params Expression<Func<TEntity, object>>[] included)
    {

        IQueryable<TEntity> query = dbSet;

        foreach(var z in included)
        {
            query=query.Include(z);
        }
        if (orderBy != null)
        {
            query = orderBy(query);
            query = query.Skip((Page.Value - 1) * 30).Take(30);
        }
        if (filter != null)
        {
            foreach (var z in filter)
            {
                query = query.Where(z);
            }
        }
        return query.ToList();
    }

    public virtual TEntity GetByID(object id)
    {
        return dbSet.Find(id);
    }

    public virtual void Insert(TEntity entity)
    {
        dbSet.Add(entity);
    }

    public virtual void Delete(object id)
    {
        TEntity entityToDelete = dbSet.Find(id);
        Delete(entityToDelete);
    }

    public virtual void Delete(TEntity entityToDelete)
    {
        if (context.Entry(entityToDelete).State == EntityState.Detached)
        {
            dbSet.Attach(entityToDelete);
        }
        dbSet.Remove(entityToDelete);
    }

    public virtual void Update(TEntity entityToUpdate)
    {
        dbSet.Attach(entityToUpdate);
        context.Entry(entityToUpdate).State = EntityState.Modified;
    }
}

和工作单位:

public class UnitOfWork {
    private EquipmentEntities context = new EquipmentEntities();
    private GenericRepository<Role> RoleRepository;
    private GenericRepository<Storage> StorageRepository;
    private GenericRepository<Device> DeviceRepository;
    private GenericRepository<DeviceInstance> DeviceInstanceRepository;
    private GenericRepository<DeviceUsage> DeviceUsageRepository;
    private GenericRepository<User> UserRepository;

    public GenericRepository<Role> roleRepository
    {
        get
        {
            if (this.RoleRepository == null)
            {
                this.RoleRepository = new GenericRepository<Role>(context);
            }
            return RoleRepository;
        }
    }

    /*
    * redundant code for other controllers
    */
    public void Save()
    {
        context.SaveChanges();
    }

    private bool disposed = false;

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

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

示例控制器:

 public class UserController : Controller
{
    //private EquipmentEntities db = new EquipmentEntities();
    private UnitOfWork unitOfWork = new UnitOfWork();

    // GET: /User/
    public ActionResult Index(string Name, string Surname, int? Page, string submit)
    {
        List<Expression<Func<User, bool>>> where = new List<Expression<Func<User, bool>>>();
        if (!string.IsNullOrEmpty(Name))
        {
            where.Add(w => w.Name.Contains(Name));
        }
        if (!string.IsNullOrEmpty(Surname))
        {
            where.Add(w => w.Surname.Contains(Surname));
        }
        var users = unitOfWork.userRepository.Get(where, null, Page, u => u.Role);
        return View(users);
    }

    // GET: /User/Details/5
    public ActionResult Details(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        User user = unitOfWork.userRepository.GetByID(id.Value);
        //User user = db.Users.Find(id);
        if (user == null)
        {
            return HttpNotFound();
        }
        return View(user);
    }

    // GET: /User/Create
    public ActionResult Create()
    {
        ViewBag.RoleId = new SelectList(unitOfWork.roleRepository.Get(null), "Id", "RoleName");
        return View();
    }

    // POST: /User/Create
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include="Id,EmployeeNo,Name,Surname,ContactInfo,RoleId")] User user)
    {
        if (ModelState.IsValid)
        {
            unitOfWork.userRepository.Insert(user);
            unitOfWork.Save();
            return RedirectToAction("Index");
        }
        ViewBag.RoleId = new SelectList(unitOfWork.roleRepository.Get(null), "Id", "RoleName", user.RoleId);
        return View(user);
    }

    // GET: /User/Edit/5
    public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        User user = unitOfWork.userRepository.GetByID(id.Value);
        if (user == null)
        {
            return HttpNotFound();
        }
        ViewBag.RoleId = new SelectList(unitOfWork.roleRepository.Get(null), "Id", "RoleName", user.RoleId);
        return View(user);
    }

    // POST: /User/Edit/5
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Edit([Bind(Include="Id,EmployeeNo,Name,Surname,ContactInfo,RoleId")] User user)
    {
        if (ModelState.IsValid)
        {
            unitOfWork.userRepository.Update(user);
            unitOfWork.Save();
            return RedirectToAction("Index");
        }
        ViewBag.RoleId = new SelectList(unitOfWork.roleRepository.Get(null), "Id", "RoleName", user.RoleId);
        return View(user);
    }

    // GET: /User/Delete/5
    public ActionResult Delete(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        User user = unitOfWork.userRepository.GetByID(id.Value);
        if (user == null)
        {
            return HttpNotFound();
        }
        if (unitOfWork.deviceUsageRepository.Get(null).Where(w => w.UserId == id) != null)
        {
            ViewBag.Error = 1;
            ModelState.AddModelError("", "Nie można kasować uyztkownika z przypisanymi urządzeniami");

        }
        else
        {
            ViewBag.Error = 0;
        }
        return View(user);
    }

    // POST: /User/Delete/5
    [HttpPost, ActionName("Delete")]
    [ValidateAntiForgeryToken]
    public ActionResult DeleteConfirmed(int id)
    {
        User user = unitOfWork.userRepository.GetByID(id);
        unitOfWork.deviceUsageRepository.Delete(user);
        unitOfWork.Save();
        return RedirectToAction("Index");
    }

    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            unitOfWork.Save();
        }
        base.Dispose(disposing);
    }
}

推荐答案

不幸的是，您的GenericRepository<T>与您的上下文紧密相关，而您的UnitOfWork实现与您的存储库紧密相关.这使得无法模拟它.

Unfortunately your GenericRepository<T> is tightly coupled with your context, and your UnitOfWork implementation if tightly coupled with your repositories. This makes it impossible to mock it.

您必须引入松散耦合:

• 添加接口IRepository<T>，并使用您的GenericRepository<T>类实现
• 添加接口IUnitOfWork并使用UnitOfWork类实现
• IUnitOfWork界面仅引用IRepository<T>，不引用引用GenericRepository<T>
• 更新您的控制器构造函数以期望使用IUnitOfWork而不是UnitOfWork.
• 最好是将存储库注入到您的工作单元中，但这将意味着很多构造函数参数，和您已经拥有了它的一个实例，而您可能没有正在使用它.我想到的解决方案是IRepositoryFactory(具有相应的实现)，它允许您根据需要创建特定的存储库.工厂将具有通用的Create方法来创建通用存储库.然后可以将该工厂注入您的工作单元实施中.

• Add an interface IRepository<T>, and implement this with your GenericRepository<T> class
• Add in interface IUnitOfWork and implement this with your UnitOfWork class
• The IUnitOfWork interface only refers to IRepository<T>, not to GenericRepository<T>
• Update your controller constructors to expect an IUnitOfWork instead of a UnitOfWork.
• Best would be to inject the repositories in you unit of work, but that would mean a lot of constructor-parameters, and you would have an instance of it already while you might not be using it. The solution to this in my mind would be a IRepositoryFactory (with a corresponding implementation), which would allow you to create a specific repository on demand. The factory would have a generic Create method to create a generic repository. This factory could then be injected in your unit-of-work implementation.

现在，您可以模拟工作单元和/或存储库的每个部分.

Now you can mock every part of you unit of work and/or repositories.

我在上面的文本和下面的代码中删除了存储库工厂.这样做的原因是，当我尝试创建伪代码时，由于将存储库工厂不知道该对象，因此在将上下文传递给通用存储库时遇到了一些麻烦.而且，由于工作单元和无论如何都紧密耦合(因为它们共享上下文对象)，所以我想出了以下解决方案:

I've removed the repository-factory in the text above, and the code below. The reason for this, is that when I tried to create pseudo-code I had a bit of trouble to pass the context to the generic-repository, since the repository-factory didn't know this object. And, since the unit-of-work and the generic-repository are both tightly coupled anyway (since they share the context-object), I've come up with the following solution:

public interface IRepository<TEntity> where TEntity: class {
    // Your methods
}
public class GenericRepository<TEntity> : IRepository<TEntity> where TEntity : class {
    public GenericRepository<TEntity>(EquipmentEntities  context) {
        // Your constructor
    }

    // Your implementation
}

public interface IUnitOfWork : IDisposable {
    IRepository<Role> RoleRepository { get; }
    IRepository<Storage> StorageRepository { get; }
    // etc

    void Save();
}

public class UnitOfWork : IUnitOfWork {
    public UnitOfWork () {
        this.context = new EquipmentEntities ();
    }

    private EquipmentEntities context = null;

    private IRepository<Role> roleRepository;
    public IRepository<Role> RoleRepository { 
        get {
            if (this.roleRepository == null) {
                this.roleRepository = new GenericRepository<Role>(context);
            }
            return this.roleRepository;
        }
    }

    // etc... other repositories
    // etc... your implementation for Save and Dispose
}

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