Модульное тестирование ASP.NET MVC с объектом MOQ

Если вы хотите сначала издеваться над ProductService, вам нужно внедрить эту зависимость.

Внедрение конструктора - это наиболее распространенный подход для контроллеров в ASP.NET MVC.

public class YourController : Controller
{
    private readonly IProductService ProductService;

    /// <summary>
    /// Constructor injection
    /// </summary>
    public YourController(IProductService productService)
    {
        ProductService = productService;
    }

    /// <summary>
    /// Code of this method has not been changed at all.
    /// </summary>
    public ActionResult Products()
    {
        ViewBag.Title = "Company Product";
        IEnumerable<ProductDetailDto> productList = ProductService.GetAllEffectiveProductDetails();
        ProductModels.ProductCategoryListModel model = new ProductModels.ProductCategoryListModel
        {
            //the type of ProductDetails => IEnumerable<productDetailDto>  
            ProductDetails = ProductService.GetAllEffectiveProductDetails(),

            //the type of ProductCategoryList => IEnumerable<selectlistitem>
            ProductCategoryList = productList.Select(x => new SelectListItem
            {
                Value = x.FKProductId.ToString(),
                Text = x.Name
            })
        };
        return View(model);
    }
}

#region DataModels

public class ProductDetailDto
{
    public int FKProductId { get; set; }
    public string Name { get; set; }
}

public class ProductModels
{
    public class ProductCategoryListModel
    {
        public IEnumerable<ProductDetailDto> ProductDetails { get; set; }
        public IEnumerable<SelectListItem> ProductCategoryList { get; set; }
    }
}

#endregion

#region Services

public interface IProductService
    {
        IEnumerable<ProductDetailDto> GetAllEffectiveProductDetails()
    }

public class ProductService : IProductService
{
    public IEnumerable<ProductDetailDto> GetAllEffectiveProductDetails()
    {
        throw new NotImplementedException();
    }
}

#endregion

Затем вы легко создаете фиктивный экземпляр IProductService, передаете его в конструктор YourController, настраиваете метод GetAllEffectiveProductDetails и проверяете возвращенный ActionResult и его model.

[TestClass]
public class YourControllerTest
{
    private Mock<IProductService> productServiceMock;

    private YourController target;

    [TestInitialize]
    public void Init()
    {
        productServiceMock = new Mock<IProductService>();

        target = new YourController(
            productServiceMock.Object);
    }

    [TestMethod]
    public void Products()
    {
        //arrange
        // There is a setup of 'GetAllEffectiveProductDetails'
        // When 'GetAllEffectiveProductDetails' method is invoked 'expectedallProducts' collection is exposed.
        var expectedallProducts = new List<ProductDetailDto> { new ProductDetailDto() };
        productServiceMock
            .Setup(it => it.GetAllEffectiveProductDetails())
            .Returns(expectedallProducts);

        //act
        var result = target.Products();

        //assert
        var model = (result as ViewResult).Model as ProductModels.ProductCategoryListModel;
        Assert.AreEqual(model.ProductDetails, expectedallProducts);
        /* Any other assertions */
    }
}