功能正常工作但不是单元测试[关闭]

Question

我正在尝试运行一些单元测试，我需要做[TestInitialize]的事情。

我在this post找到了一些信息。我不知道如何解决它，因为它对我没有意义。

[TestInitialize]
public void TestInitialize()
{
    mock = new Mock<ILibraryRepository>();

    books = new List<Book>()
    {
        new Book { Id = 0, Title = "Title 0", Edition = 0, PublicationDate = DateTime.Now, Author = { Id = 0, Name = "Author 0", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 0 },
        new Book { Id = 1, Title = "Title 1", Edition = 1, PublicationDate = DateTime.Now, Author = { Id = 1, Name = "Author 1", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 1 },
        new Book { Id = 2, Title = "Title 2", Edition = 2, PublicationDate = DateTime.Now, Author = { Id = 2, Name = "Author 2", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 2 }
    };

    mock.Setup(m => m.Books).Returns(books.AsQueryable());

    var controller = new BooksController(mock.Object);
}

它看起来一切都很好。但是当我运行这个测试时：

[TestMethod]
public void IndexLoadsValid()
{
    // Arrange
    var controller = new BooksController(mock.Object);

    // Act
    var result = controller.Index() as ViewResult;

    // Assert
    Assert.IsNotNull(result);
}

我收到以下错误：

你调用的对象是空的

这很清楚。它是空的。但我不明白为什么它是空的？

调试说：

System.NullReferenceException: 'Object reference not set to an instance of an object.'

Assignment2.Models.Book.Author.get returned null.

这对我来说没有意义，因为当我启动程序时这个功能起作用。

Book模型在这里：

public class Book
{
    [Key]
    public int Id { get; set; }

    [Required]
    public string Title { get; set; }

    [Display(Name = "Publication date")]
    public DateTime? PublicationDate { get; set; }

    public float? Edition { get; set; } // We might have a 2.5 edition. Rare but happens

    public int AuthorId { get; set; }

    public Author Author { get; set; }
}

我不知道它是否有帮助，但我的ILibraryRepository在这里：

public interface ILibraryRepository
{
    IQueryable<Book> Books { get; }
    IQueryable<Author> Authors { get; }

    Book Save(Book book);
    Author Save(Author author);

    void Delete(Book book);
    void Delete(Author author);
}

知道我为什么会收到这个错误吗？

编辑：我把HomeController改为BooksController。我不知道为什么我把这两个混在了一起。错误发生在[TestInitialize]部分

Answer 1

您的初始化方法正好为零。基本上，您需要花费大量精力将模拟分配给初始化方法“var controller”中的临时局部变量，这是您在测试中未使用的。如果这还不够，它甚至是你的测试方法所使用的不同控制器。你需要做这样的事情：

private HomeController controller;

[TestInitialize]
public void TestInitialize()
{
    mock = new Mock<ILibraryRepository>();

    books = new List<Book>()
    {
        new Book { Id = 0, Title = "Title 0", Edition = 0, PublicationDate = DateTime.Now, Author = { Id = 0, Name = "Author 0", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 0 },
        new Book { Id = 1, Title = "Title 1", Edition = 1, PublicationDate = DateTime.Now, Author = { Id = 1, Name = "Author 1", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 1 },
        new Book { Id = 2, Title = "Title 2", Edition = 2, PublicationDate = DateTime.Now, Author = { Id = 2, Name = "Author 2", DateOfBirth = DateTime.Now, DateOfDeath = DateTime.Now }, AuthorId = 2 }
    };

    mock.Setup(m => m.Books).Returns(books.AsQueryable());

    controller = new HomeController(mock.Object);
}

[TestMethod]
public void IndexLoadsValid()
{
    // Arrange - use arrange from test initialise

    // Act
    var result = controller.Index() as ViewResult;

    // Assert
    Assert.IsNotNull(result);
}

并不是说这是最好的做法，但你需要实际使用初始化方法的结果，而不是让它被垃圾收集，如果你想让测试使用它。

Answer 2

您使用了Author = {Id = 0，etc}，它假定Books构造函数也实例化了作者，但它仍为null。如果您需要有关例外的帮助，请包含堆栈跟踪

Answer 3

正如@PaulAbbott所说：

Author = { Id = 0...应该是Author = new Author() { Id = 0...