Question

我使用的

UX控件框架需要MVC控制器上的扩展方法。当nUnit尝试调用该方法时（用于将部分视图打包到Json中），将引发一个空对象引用。

该框架的作者建议通过接口调用该方法，但这只是推迟了null错误。

是否可以使用扩展方法从控制器测试ActionResult？

Controller Create（）方法从扩展方法返回结果部分：

return Json(new { Content = viewRender.RenderPartialView(this, "ListItems/SimpleSyllabi", new[] { nS }) });

扩展方法签名为

 public static string RenderPartialView(this Controller controller, string viewName, object model = null, bool removeWhiteSpace = true);

错误很简单：

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

结果StackTrace：

at System.Web.Mvc.VirtualPathProviderViewEngine.FindPartialView(ControllerContext controllerContext, String partialViewName, Boolean useCache)
   at System.Web.Mvc.ViewEngineCollection.<>c__DisplayClass2.<FindPartialView>b__0(IViewEngine e)
   at System.Web.Mvc.ViewEngineCollection.Find(Func`2 lookup, Boolean trackSearchedPaths)
   at System.Web.Mvc.ViewEngineCollection.FindPartialView(ControllerContext controllerContext, String partialViewName)
   at Omu.AwesomeMvc.ControllerExtensions.RenderView(Controller controller, String viewName, Object model, String master, Boolean partial, Boolean removeWhiteSpace)
   at Omu.AwesomeMvc.ControllerExtensions.RenderPartialView(Controller controller, String viewName, Object model, Boolean removeWhiteSpace)
   at Flipprs.nUnitHelpers.Awesome.ViewRender.RenderPartialView(Controller controller, String viewName, Object model, Boolean removeWhiteSpace) in A:\Stephan\Source\Workspaces\AchievementCards\Develop-Payment(v0.0.11.0)\Flipprs.Web\Helpers\Awesome\nUnitHelpers.cs:line 17
   at Flipprs.Controllers.SyllabusAjaxListController.Create(SyllabusCreateViewModel scvm) in A:\Stephan\Source\Workspaces\AchievementCards\Develop-Payment(v0.0.11.0)\Flipprs.Web\Controllers\SyllabusAjaxListController.cs:line 217
   at Flipprs.Tests.Controllers.SyllabusAjaxListControllerTest.SyllabusAjaxListController_CreatePUT_ReturnsJson(String HTTPreqAUEmail) in A:\Stephan\Source\Workspaces\AchievementCards\Develop-Payment(v0.0.11.0)\Flipprs.Tests\Controllers\SyllabusAjaxListControllerTest.cs:line 484
Result Message: System.NullReferenceException : Object reference not set to an instance of an object.

集成测试“设置”：

 private IViewRender viewRender;

viewRender = new ViewRender();



controller = new SyllabusAjaxListController(viewRender, photoPlaceholderService, activityService, syllabusService,
            userService, organisationService, userManager);

然后参加测试（节选）

  [Test, Sequential]
            public void SyllabusAjaxListController_CreatePUT_ReturnsJson()
{
    ActionResult result_ar = controller.Create(validModel);

            JsonResult result = result_ar as JsonResult;
}

集成测试模型

        Mock<ControllerContext> controllerContext;
        Mock<HttpContext> httpContext;
        Mock<HttpContextBase> contextBase;
        Mock<HttpRequestBase> httpRequest;
        Mock<HttpResponseBase> httpResponse;

        Mock<IIdentity> identity;
        Mock<IPrincipal> principal;
        Mock<GenericPrincipal> genericPrincipal;

Answer 1

被测对象似乎与第三者的实施担忧紧密相关，这使得孤立地进行测试变得困难。

我建议模拟原始语句中引用的视图渲染抽象

getVauleAt(...)

在调用时返回一个字符串，以便被测方法可以完成并可以断言预期的行为。

public interface IViewRender {
    string RenderPartialView(Controller controller, string viewName, object model = null, bool removeWhiteSpace = true);
}

nUnit测试控制器扩展方法

1 个答案: