Asp.net mvc 3 Moq正在显示404错误

我有以下404错误ActionResult，当找不到网页时会抛出：

public ActionResult InvokeHttp404(HttpContextBase httpContext) {
      IController errorController = new ErrorController();
      var errorRoute = new RouteData();
      errorRoute.Values.Add("controller", "Error");
      errorRoute.Values.Add("action", "Http404");
      errorRoute.Values.Add("url", httpContext.Request.Url.OriginalString);
      errorController.Execute(new RequestContext(httpContext, errorRoute));
      return new EmptyResult();
    }

我试图通过以下测试对其进行单元测试：

[TestMethod]
        public void Details_Get_404Handler()
        {
            // Arrange
            var controller = GetController(new Repository(), FakeHttpContext());

            // Act
            var result = controller.Details(3442399) as ViewResult; // invalid Id (not found)

            //Assert
            Assert.AreEqual("NotFound", result.ViewName);
        }

我已经在这个测试上呆了很长时间了，它会在请求

Url.OriginalString

的代码行上抛出一个null异常。在阅读了之前的文章后，我发现第二个答案非常有帮助，如下所示：（我添加了一行内容来处理Url字符串）

根据Marnix的回答修改代码：

public static HttpContextBase FakeHttpContext()
        {
            var context = new Mock<HttpContextBase>();
            var request = new Mock<HttpRequestBase>();
            var response = new Mock<HttpResponseBase>();
            var session = new Mock<HttpSessionStateBase>();
            var server = new Mock<HttpServerUtilityBase>();
            var user = new Mock<IPrincipal>();
            var identity = new Mock<IIdentity>();
            var files = new Mock<HttpFileCollectionBase>();



            request.SetupGet(x => x.Url).Returns(new Uri("http://localhost/a", UriKind.Absolute));
            request.Setup(req => req.ApplicationPath).Returns("~/");
            request.Setup(req => req.AppRelativeCurrentExecutionFilePath).Returns("~/");
            request.Setup(req => req.PathInfo).Returns(string.Empty);
            request.Setup(req => req.ContentType).Returns("text/html");
            request.Setup(req => req.QueryString).Returns(new NameValueCollection());
            request.Setup(req => req.Form).Returns(new NameValueCollection());
            request.Setup(req => req.Files).Returns(files.Object);
            response.Setup(res => res.ApplyAppPathModifier(It.IsAny<string>()))
                .Returns((string virtualPath) => virtualPath);
            user.Setup(usr => usr.Identity).Returns(identity.Object);
            identity.SetupGet(ident => ident.IsAuthenticated).Returns(true);
            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.Object);

            ValueProviderFactories.Factories
                .ReplaceNameValueCollectionWith<FormValueProviderFactory>(ctx => ctx.HttpContext.Request.Form)
                .ReplaceNameValueCollectionWith<QueryStringValueProviderFactory>(ctx => ctx.HttpContext.Request.QueryString)
                .ReplaceHttpFileCollectionWith<HttpFileCollectionValueProviderFactory>(ctx => ctx.HttpContext.Request.Files);

            return context.Object;
        }

---

模拟控制器的上下文有点棘手。在MVC3中，还有一个额外的步骤来防止值提供程序接触HttpContext.Current

解释你需要做什么

更新：您可能不会直接使用ValueProviderFactorys，但控制器上的ActionInvoker会直接使用。在深层的某个地方，值提供程序的默认实现访问HttpContext.Current，HttpContext.Current不是在web请求之外设置的，在单元测试期间会导致NullReferenceException。您可以通过替换默认值提供程序（如链接答案中所述）来防止这种情况

将上面链接中的

valueProviderFactoryExtensions

类复制到您的测试项目中，并将以下代码添加到您的

FakeHttpContext

方法中：

var form = new NameValueCollection();
var queryString = new NameValueCollection();

request.Setup( x => x.Form ).Returns( form );
request.Setup( x => x.QueryString ).Returns( queryString );

ValueProviderFactories.Factories
.ReplaceWith<FormValueProviderFactory>(ctx => form)
.ReplaceWith<QueryStringValueProviderFactory>(ctx => queryString);

var form=new NameValueCollection（）；
var queryString=new NameValueCollection（）；
request.Setup（x=>x.Form）.Returns（Form）；
request.Setup（x=>x.QueryString）.Returns（QueryString）；
价值提供者工厂。工厂
.ReplaceWith（ctx=>form）
.replace为（ctx=>queryString）；

我有一个像问题中那个家伙一样的错误控制器，但我要问的是如何使用MOQ对404错误控制器进行单元测试。以前没有使用ValueProviderFactorys，考虑到您所指的问题中有ValueProviderFactoryExtensions类，我可以从测试方法中显示如何调用它们吗？如果有人有解决方案，我仍然希望在Moq中看到解决方案…我更新了我的答案，解释了如何以及为什么需要调整ValueProviderFactorys。测试结果详细信息中的堆栈跟踪现在已经超过了namevaluecollections，但现在似乎无法找到viewname？我已经发布了我在我的问题中使用的更新代码-它和你说的不完全一样，但有相同的区别，对吗？看起来差不多。我的最佳猜测是，您的错误控制器正在尝试返回视图结果。调用

Execute

时，将执行整个管道，包括视图。由于您正在进行单元测试，ViewEngine很可能无法找到视图。你有两个选择；终止视图引擎或重新考虑实现控制器的方式。例如，您可以抛出错误代码为404的HttpException，并使用自定义HandleErrorAttribute实现处理该异常。这将使您的控制器更易于测试。

public static HttpContextBase FakeHttpContext()
        {
            var context = new Mock<HttpContextBase>();
            var request = new Mock<HttpRequestBase>();
            var response = new Mock<HttpResponseBase>();
            var session = new Mock<HttpSessionStateBase>();
            var server = new Mock<HttpServerUtilityBase>();
            var user = new Mock<IPrincipal>();
            var identity = new Mock<IIdentity>();
            var files = new Mock<HttpFileCollectionBase>();



            request.SetupGet(x => x.Url).Returns(new Uri("http://localhost/a", UriKind.Absolute));
            request.Setup(req => req.ApplicationPath).Returns("~/");
            request.Setup(req => req.AppRelativeCurrentExecutionFilePath).Returns("~/");
            request.Setup(req => req.PathInfo).Returns(string.Empty);
            request.Setup(req => req.ContentType).Returns("text/html");
            request.Setup(req => req.QueryString).Returns(new NameValueCollection());
            request.Setup(req => req.Form).Returns(new NameValueCollection());
            request.Setup(req => req.Files).Returns(files.Object);
            response.Setup(res => res.ApplyAppPathModifier(It.IsAny<string>()))
                .Returns((string virtualPath) => virtualPath);
            user.Setup(usr => usr.Identity).Returns(identity.Object);
            identity.SetupGet(ident => ident.IsAuthenticated).Returns(true);
            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.Object);

            ValueProviderFactories.Factories
                .ReplaceNameValueCollectionWith<FormValueProviderFactory>(ctx => ctx.HttpContext.Request.Form)
                .ReplaceNameValueCollectionWith<QueryStringValueProviderFactory>(ctx => ctx.HttpContext.Request.QueryString)
                .ReplaceHttpFileCollectionWith<HttpFileCollectionValueProviderFactory>(ctx => ctx.HttpContext.Request.Files);

            return context.Object;
        }

System.Web.Mvc.ViewResult.FindView(ControllerContext context)

var form = new NameValueCollection();
var queryString = new NameValueCollection();

request.Setup( x => x.Form ).Returns( form );
request.Setup( x => x.QueryString ).Returns( queryString );

ValueProviderFactories.Factories
.ReplaceWith<FormValueProviderFactory>(ctx => form)
.ReplaceWith<QueryStringValueProviderFactory>(ctx => queryString);