使用依赖注入和最小起订量进行单元测试

Question

我只是在学习依赖注入和模拟是如何工作的，但我想要一些关于我如何设置几个测试的反馈。我可以让他们通过，但我不确定这是否是我所需要的。

这是一个 MVC 应用程序，它对 return 数据进行 Web API 调用。对于这个例子，我是运行 Web API 中填充下拉列表的查询。

请给我任何和所有关于我在这里做对或错的建议，或者我应该做的不同的事情。

依赖注入的安装文件 - Unity.WebAPI（NuGet 包）

UnityConfig.cs

public static class UnityConfig
{
    public static void RegisterComponents()
    {
        var container = new UnityContainer();

        // register all your components with the container here
        // it is NOT necessary to register your controllers

        // e.g. container.RegisterType<ITestService, TestService>();

        container.RegisterType<IDropDownDataRepository, DropDownDataRepository>();

        GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
    }
}

控制器

public class DropDownDataController : ApiController
{  
    private IDropDownDataRepository _dropDownDataRepository;

    //Dependency Injection (I'm using Unity.WebAPI)
    public DropDownDataController(IDropDownDataRepository dropDownDataRepository)
    {
        _dropDownDataRepository = dropDownDataRepository;
    }

    [HttpGet]
    public HttpResponseMessage DateList()
    {
        try
        {
            return _dropDownDataRepository.DateList();
        }
        catch
        {
            throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
        }
    }
}

存储库

public class DropDownDataRepository : IDropDownDataRepository
{
    //Is this fine in here, or should it be injected somehow too?
    private MyDatabaseEntities db = new MyDatabaseEntities();  

    public HttpResponseMessage DateList()
    {
        var sourceQuery = (from p in db.MyProcedure()
                           select p).ToList();

        string result = JsonConvert.SerializeObject(sourceQuery);
        var response = new HttpResponseMessage();
        response.Content = new StringContent(result, System.Text.Encoding.Unicode, "application/json");

        return response;
    }
}

接口

public interface IDropDownDataRepository
{
    HttpResponseMessage DateList();
}

单元测试

/// <summary>
/// Tests the DateList method is run
/// I pieced this kind of test together from examples online
/// I'm assuming this is good for a simple test
/// </summary>
[TestMethod]
public void DateListTest1()
{
    //Arrange
    var mockRepository = new Mock<IDropDownDataRepository>();
    mockRepository.Setup(x => x.DateList());           
    var controller = new DropDownDataController(mockRepository.Object);

    //Act
    controller.DateList();

    //Assert
    mockRepository.VerifyAll();
}



/// <summary>
/// Tests the DateList method returns correct status code.
/// This will run with success, but I'm not sure if that's just
/// because I'm telling it to return what I'm expecting.  
/// I welcome suggestions for improvement.
/// </summary>
[TestMethod]
public void DateListTest2()
{
    //Arrange
    var mockRepository = new Mock<IDropDownDataRepository>();
    mockRepository
        .Setup(x => x.DateList())
        //This will only succeed if I have the Returns property here,
        //but isn't that just bypassing the actual "test" of whether or
        //not this works?
        .Returns(new HttpResponseMessage(HttpStatusCode.OK));

    DropDownDataController controller = new DropDownDataController(mockRepository.Object);
    controller.Request = new HttpRequestMessage();
    controller.Configuration = new HttpConfiguration();

    //Act            
    var response = controller.DateList();

    //Assert
    Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
}

更新 1

我的主要问题之一是 .Returns 属性的实际作用。在我的第二个单元测试中，我告诉它 return OK，然后检查它是否 return OK。我看不出这实际上是如何测试任何东西的。

Answer 1

One of my main questions here is what the .Returns property actually does. In my second unit test, I'm telling it to return OK, then check if it returns OK. I can't see how that's actually testing anything.

代码：

mockRepository
        .Setup(x => x.DateList())
        //This will only succeed if I have the Returns property here,
        //but isn't that just bypassing the actual "test" of whether or
        //not this works?
        .Returns(new HttpResponseMessage(HttpStatusCode.OK));

说当 mockRepository 收到对 DateList() 的呼叫时，它应该 return 一个 new HttpResponseMessage(HttpStatusCode.OK).

所以里面

    [HttpGet]
    public HttpResponseMessage DateList()

单元测试到线时

return _dropDownDataRepository.DateList();

模拟对象触发并且 returns new HttpResponseMessage(HttpStatusCode.OK)

此测试的更好名称应该是 DateListTest2，类似于 DateList_Returns_Status_Code_From_Repository，因为这就是您在测试中安排的名称。

老实说 controller.DateList() 没有太多逻辑，所以这是你唯一可以拥有的黄金路径测试。

使用依赖注入和最小起订量进行单元测试

Unit Testing With Dependency Injection and MOQ

asp.net-mvc

unit-testing

moq

mocking

unity-container