模拟对象无法返回所需的对象

Question

我肯定会忽略一些明显的东西-通常是当我遇到这样的问题时。

我有一个仅根据提供的ID返回新闻文章的控制器：

[HandleError]
public class HomeController : Controller
{
    private readonly IArticleRepository articleRepository;

    public HomeController(IArticleRepository Repository)
    {
        articleRepository = Repository;
    }

    public ActionResult Index()
    {
        return View("Index");
    }

    // Here's the bit we're interested in
    public ActionResult Article(int id)
    {
        var article = articleRepository.GetById(id);

        return View("Article", article);
    }

}

我像这样用Moq来嘲笑这个：

[TestFixture]
public class HomeControllerTests
{
    HomeController controller;
    int articleId;
    Article model;

    [TestFixtureSetUp]
    public void SetupMethods()
    {
        Mock<IArticleRepository> repositoryMock = new Mock<IArticleRepository>();
        repositoryMock.Setup(x => x.GetById(articleId)).Returns(GetSampleArticle());

        controller = new HomeController(repositoryMock.Object);
    }

    [Test]
    public void Article_Action_Returns_Requested_Article()
    {
        // Arrange
        model = new Article();
        articleId = 1;

        // Act
        ActionResult result = controller.Article(articleId);

        // Assert
        var viewResult = ((ViewResult)result);
        var returnedModel = viewResult.Model;
        Assert.IsInstanceOf<Article>(viewResult.Model);
        //Assert.AreEqual(articleId, returnedModel.ID);
    }
}

上面讨论的“ GetSampleArticle”方法如下所示：

    private Article GetSampleArticle()
    {
        Article article = new Article()
        {
            Archived = false,
            Body = "<p>This is a dummy sample article for use in our mocks.</p>",
            EndDate = DateTime.Today.AddDays(30),
            ID = 1,
            Priority = 3,
            StartDate = DateTime.Today,
            Title = "Sample Article"
        };

        return article;
    }

但是我仍然得到该模型的空类型。 那我忘了什么呢？

News.Tests.Controllers.HomeControllerTests.Article_Action_Returns_Requested_Article:
  Expected: instance of <News.Data.Article>
  But was:  null

Answer 1

另一个想法是使用It.IsAny（）方法来避免完全寻找硬编码值：

repositoryMock.Setup(x => x.GetById(It.IsAny<int>())).Returns(GetSampleArticle());

这样做是安全的，因为您并不在乎articleId的实际值，而在乎其检索机制。

Answer 2

在您的SetupMethods中，articleId为0。

在测试中，将其设置为1，因此不会调用.Setup 。 我会将您的安装程序移至您的测试中。

[Test]
public void Article_Action_Returns_Requested_Article()
{
    // Arrange
    model = new Article();
    articleId = 1;

    Mock<IArticleRepository> repositoryMock = new Mock<IArticleRepository>();
    repositoryMock.Setup(x => x.GetById(articleId)).Returns(GetSampleArticle());

    controller = new HomeController(repositoryMock.Object);

    // Act
    ActionResult result = controller.Article(articleId);

    // Assert
    var viewResult = ((ViewResult)result);
    var returnedModel = viewResult.Model;
    Assert.IsInstanceOf<Article>(viewResult.Model);
    //Assert.AreEqual(articleId, returnedModel.ID);
}