Asp.Net核心單元測試異步控制器

Question

我有這樣的試驗：

[Fact] 
public async void Can_Paginate() 
{ 
    //fake data 
    var product1 = new Product { ProductId = 1, ProductName = "P1" }; 
    var product2 = new Product { ProductId = 2, ProductName = "Product 2" }; 
    var product3 = new Product { ProductId = 3, ProductName = "Product 3" }; 
    var product4 = new Product { ProductId = 4, ProductName = "Product 4" }; 
    var product5 = new Product { ProductId = 5, ProductName = "Product 5" }; 
    var data = new List<Product> 
    { 
     product1, 
     product2, 
     product3, 
     product4, 
     product5 
    }.ToAsyncEnumerable(); 

     var category1 = new Category { CategoryId = 1 }; 

     var prodCategoryData = new List<ProductCategory> 
     { 
      new ProductCategory { Product =product1,Category = category1}, 
      new ProductCategory { Product =product2,Category = category1}, 
      new ProductCategory { Product =product3,Category = category1}, 
      new ProductCategory { Product =product4,Category = category1}, 
      new ProductCategory { Product =product5,Category = category1} 
     }.ToAsyncEnumerable(); 

     var dbSetMock = new Mock<DbSet<Product>>(); 
     //dbSetMock.As<IQueryable<Product>>().Setup(m => m.Provider).Returns(data.Provider); 
     //dbSetMock.As<IQueryable<Product>>().Setup(m => m.Expression).Returns(data.Expression); 
     //dbSetMock.As<IQueryable<Product>>().Setup(m => m.ElementType).Returns(data.ElementType); 
     //dbSetMock.As<IQueryable<Product>>().Setup(m => m.GetEnumerator()).Returns(data.GetEnumerator()); 

     var pcDbSetMock = new Mock<DbSet<ProductCategory>>(); 
     // pcDbSetMock.As<IQueryable<ProductCategory>>().Setup(m => m.Provider).Returns(prodCategoryData.Provider); 
     //pcDbSetMock.As<IQueryable<ProductCategory>>().Setup(m => m.Expression).Returns(prodCategoryData.Expression); 
     //pcDbSetMock.As<IQueryable<ProductCategory>>().Setup(m => m.ElementType).Returns(prodCategoryData.ElementType); 
     //pcDbSetMock.As<IQueryable<ProductCategory>>().Setup(m => m.GetEnumerator()).Returns(prodCategoryData.GetEnumerator()); 

     Mock<ApplicationDbContext> customDbContextMock = new Mock<ApplicationDbContext>(); 
     customDbContextMock.Setup(x => x.Products).Returns(dbSetMock.Object); 
     customDbContextMock.Setup(x => x.ProductCategories).Returns(pcDbSetMock.Object); 

     var loggerMock = new Mock<ILogger<ProductsController>>(); 
     var envMock = new Mock<IHostingEnvironment>(); 
     var httpContext = new Mock<HttpContext>().Object; 
     var actionDescriptor = new Mock<Microsoft.AspNetCore.Mvc.Controllers.ControllerActionDescriptor>().Object; 
     var modelState = new ModelStateDictionary(); 
     var actionContext = new ActionContext(httpContext, new Mock<RouteData>().Object, actionDescriptor, modelState); 

     ProductsController controller = new ProductsController(customDbContextMock.Object, loggerMock.Object, envMock.Object); 
     controller.pageSize = 3; 
     controller.ControllerContext = new ControllerContext(actionContext); 
     var result = await controller.List(1, 2); 

我的控制器邏輯：

public async Task<IActionResult> List(int Id, int page = 1) 
{ 

    if (Id == 0) 
    { 
     ViewBag.CategoryName = "Wszystkie produkty"; 
     return View(await _context.ProductCategories.Include(c => c.Product).ToListAsync()); 
    } 

    return View(await _context.ProductCategories 
     .Include(p => p.Product) 
     .Where(pt => pt.CategoryId == Id) 
     .OrderBy(p=>p.ProductId) 
     .Skip((page-1)*pageSize) 
     .ToListAsync()); 
} 

我的問題是，我無法通過使用prodCategoryData和數據列表作爲IAsyncEnumerable嘲笑_context.ProductCategories 。

當我將它們轉換成IQueryable我得到這個錯誤，而不是：

附加信息：源的IQueryable沒有實現IAsyncEnumerable。只有實現IAsyncEnumerable的源才能用於實體框架。

Answer 1

使用測試類從這樣的回答：

How to mock an async repository with Entity Framework Core

以下通用擴展方法，推導

public static Mock<DbSet<T>> ToAsyncDbSetMock<T>(this IEnumerable<T> source) 
    where T : class { 

    var data = source.AsQueryable(); 

    var mockSet = new Mock<DbSet<T>>(); 

    mockSet.As<IAsyncEnumerable<T>>() 
     .Setup(m => m.GetEnumerator()) 
     .Returns(new TestAsyncEnumerator<T>(data.GetEnumerator())); 

    mockSet.As<IQueryable<T>>() 
     .Setup(m => m.Provider) 
     .Returns(new TestAsyncQueryProvider<T>(data.Provider)); 

    mockSet.As<IQueryable<T>>().Setup(m => m.Expression).Returns(data.Expression); 
    mockSet.As<IQueryable<T>>().Setup(m => m.ElementType).Returns(data.ElementType); 
    mockSet.As<IQueryable<T>>().Setup(m => m.GetEnumerator()).Returns(() => data.GetEnumerator()); 

    return mockSet; 
} 

利用上述擴展方法的測試可以被重構爲

[Fact] 
public async Task Can_Paginate() { 

    //Arrange 

    var products = GetFakeProducts().ToAsyncDbSetMock();  
    var productCategories = GetFakeProductCategories().ToAsyncDbSetMock(); 

    var customDbContextMock = new Mock<ApplicationDbContext>(); 
    customDbContextMock.Setup(x => x.Products).Returns(products.Object); 
    customDbContextMock.Setup(x => x.ProductCategories).Returns(productCategories.Object); 

    //...other code removed for brevity 

    var controller = new ProductsController(customDbContextMock.Object, loggerMock.Object, envMock.Object); 
    controller.pageSize = 3; 
    controller.ControllerContext = new ControllerContext(actionContext); 

    //Act 
    var result = await controller.List(1, 2); 

    //Assert 

    //...other code removed for brevity 
} 

Answer 2

如果您不想編寫大量基礎架構代碼，則可以使用第三方斷言庫，如https://MyTestedASP.NET的MyTested.AspNetCore.Mvc。它會自動嘲笑你的數據庫對象。這裏有一個例子：

MyMvc 
.Controller<MvcController>() 
.WithOptions(options => options 
    .For<AppSettings>(settings => settings.Cache = true)) 
.WithSession(session => session 
    .WithEntry("Session", "SessionValue")) 
.WithDbContext(db => db.WithEntities(entities => entities 
    .AddRange(SampleDataProvider.GetModels()))) 
.Calling(c => c.SomeAction()) 
.ShouldHave() 
.MemoryCache(cache => cache 
    .ContainingEntry(entry => entry 
     .WithKey("CacheEntry") 
     .WithSlidingExpiration(TimeSpan.FromMinutes(10)) 
     .WithValueOfType<CachedModel>() 
     .Passing(a => a.Id == 1))) 
.AndAlso() 
.ShouldReturn() 
.View() 
.WithModelOfType<ResponseModel>();