基本 MVC3 UnitTest 无法 UpdateModel()

Question

我已经有一段时间没有做任何 MVC 工作了，所以我希望我错过了一些东西。我正在尝试编写一个测试和控制器操作来简单地编辑一个名为“业务”的 DTO。

控制器动作：

[HttpPost]
public ActionResult Edit(string id, Business business)
{
    try
    {
        var model = _businessRepository.Get(id);

        if (model != null)
        {
            UpdateModel(model);

            if (ModelState.IsValid)
            {
                _businessRepository.Save(model);
            }
            else
            {
                return View(business);
            }
        }

        return RedirectToAction("Index");
    }
    catch
    {
        return View();
    }
}

测试：

[TestMethod]
public void Edit_Post_Action_Updates_Model_And_Redirects()
{
    // Arrange
    var mockBusinessRepository = new Mock<IBusinessRepository>();
    var model = new Business { Id = "1", Name = "Test" };
    var expected = new Business { Id = "1", Name = "Not Test" };

    // Set up result for business repository
    mockBusinessRepository.Setup(m => m.Get(model.Id)).Returns(model);
    mockBusinessRepository.Setup(m => m.Save(expected)).Returns(expected);
    var businessController = new BusinessController(mockBusinessRepository.Object);

    // Act
    var result = businessController.Edit(model.Id, expected) as RedirectToRouteResult;

    // Assert
    Assert.IsNotNull(result);
    Assert.AreEqual(result.RouteValues["action"], "Index");
    mockBusinessRepository.VerifyAll();
}

它给出异常的行是控制器中的 UpdateModel()。异常详情如下：

“值不能为空。参数名称：controllerContext”

Answer 1

我在 Gist 上有一些代码，通常用于设置 ControllerContext。该代码是最初取自 Hanselman 博客的修改版本。

https://gist.github.com/1578697 (MvcMockHelpers.cs)

Answer 2

设置控制器上下文

以下是我从事的一个项目的代码 sn-p，所以可能对你来说太多了

public class TestBase
    {
        internal Mock<HttpContextBase> Context;
        internal Mock<HttpRequestBase> Request;
        internal Mock<HttpResponseBase> Response;
        internal Mock<HttpSessionStateBase> Session;
        internal Mock<HttpServerUtilityBase> Server;
        internal GenericPrincipal User;

            public void SetContext(Controller controller)
            {
              Context = new Mock<HttpContextBase>();
              Request = new Mock<HttpRequestBase>();
              Response = new Mock<HttpResponseBase>();
              Session = new Mock<HttpSessionStateBase>();
              Server = new Mock<HttpServerUtilityBase>();
       User = new GenericPrincipal(new GenericIdentity("test"), new string[0]);

              Context.Setup(ctx => ctx.Request).Returns(Request.Object);
              Context.Setup(ctx => ctx.Response).Returns(Response.Object);
              Context.Setup(ctx => ctx.Session).Returns(Session.Object);
              Context.Setup(ctx => ctx.Server).Returns(Server.Object);
              Context.Setup(ctx => ctx.User).Returns(User);

              Request.Setup(r => r.Cookies).Returns(new HttpCookieCollection());
              Request.Setup(r => r.Form).Returns(new NameValueCollection());
      Request.Setup(q => q.QueryString).Returns(new NameValueCollection());
              Response.Setup(r => r.Cookies).Returns(new HttpCookieCollection());

              var rctx = new RequestContext(Context.Object, new RouteData());
controller.ControllerContext = new ControllerContext(rctx, controller);
            }
}

那么在你的测试中你可以安排：

//Arrange
SetContext(_controller);
Context.Setup(ctx => ctx.Request).Returns(Request.Object);

如果您想用 ModelState 错误测试您的方法，请添加：

_controller.ModelState.AddModelError("Name", "ErrorMessage");

Answer 3

您需要为您的BusinessController 模拟ControllerContext。

见this question 或this one。

Answer 4

我已经设法通过使用 Automapper 而不是 UpdateModel 来实现我想要的工作。

我在自动映射器初始化中添加了（IPersistable 是我所有 DTO 的接口）：

Mapper.CreateMap<IPersistable, IPersistable>().ForMember(dto => dto.Id, opt => opt.Ignore());

然后我将控制器操作更改为：

[HttpPost]
public ActionResult Edit(string id, Business business)
{
    try
    {
        var model = _businessRepository.Get(id);

        if (model != null)
        {
            Mapper.Map(business, model);

            if (ModelState.IsValid)
            {
                _businessRepository.Save(model);
            }
            else
            {
                return View(business);
            }
        }

        return RedirectToAction("Index");
    }
    catch
    {
        return View();
    }
}

并将我的测试更改为：

[TestMethod]
public void Edit_Post_Action_Updates_Model_And_Redirects()
{
    // Arrange
    var mockBusinessRepository = new Mock<IBusinessRepository>();
    var fromDB = new Business { Id = "1", Name = "Test" };
    var expected = new Business { Id = "1", Name = "Not Test" };

    // Set up result for business repository
    mockBusinessRepository.Setup(m => m.Get(fromDB.Id)).Returns(fromDB);
    mockBusinessRepository.Setup(m => m.Save(It.IsAny<Business>())).Returns(expected);
    var businessController = new BusinessController(mockBusinessRepository.Object) {ControllerContext = new ControllerContext()};

    //Act
    var result = businessController.Edit(fromDB.Id, expected) as RedirectToRouteResult;

    // Assert
    Assert.IsNotNull(result);
    Assert.AreEqual(result.RouteValues["action"], "Index");
    mockBusinessRepository.VerifyAll();
}

Answer 5

我遇到了同样的问题，并使用堆栈跟踪将其锁定到 ValueProvider。基于 Andrew 上面关于模拟控制器使用的一些底层对象的答案，我设法通过像这样模拟 ValueProvider 来解决空值异常：

var controller = new MyController();

// ... Other code to mock objects used by controller ...

var mockValueProvider = new Mock<IValueProvider>();
controller.ValueProvider = mockValueProvider.Object;

// ... rest of unit test code which relies on UpdateModel(...)