c# - 测试函数 "System.Web.Mvc.ViewEngines.Engines.FindPartialView"

Question

我想(单元)测试函数 System.Web.Mvc.ViewEngines.Engines.FindPartialView 并检查 HTML 代码是否正确返回。

但是每次我开始单元测试时，它都会抛出一个“Object reference not set to an instance of an object”异常。

我已尝试通过 .net 框架源代码进行调试，但调试器变得迷失方向并随机跳转/中断而没有任何消息。

现在我想知道我在 FakeControllerContext 中遗漏了什么元素以及如何修复它。

这是我的代码:

public static string RenderPartialViewToString(string viewName, object model, ControllerContext controller)
{
    if (string.IsNullOrEmpty(viewName))
        viewName = controller.RouteData.GetRequiredString("action");

    controller.Controller.ViewData.Model = model;

    using (var sw = new StringWriter())
    {
        //"Error: ***.Shop.UnitTests.RenderStuffTest.RenderPartialViewToStringTest-Test method threw an exception: System.NullReferenceException – Object reference not set to an instance of an object"
        ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(controller, viewName);
        controller.Controller.ViewData.Model = model;
        controller.Controller.ViewBag.Part = true;

        var viewContext = new ViewContext(controller, viewResult.View, controller.Controller.ViewData,
                                      controller.Controller.TempData, sw);
        viewResult.View.Render(viewContext, sw);

        return sw.GetStringBuilder().ToString();
    }
}

这是我的测试:

    [TestMethod]
    public void RenderPartialViewToStringTest()
    {
            const string viewName = "_navi";
            var customersController = new ArticleController();
            customersController.ControllerContext = new FakeControllerContext(customersController)                                      {                                                           RouteData =
                                                        {
                                                            Route =
                                                                new Route(
                                                                "{language}/{controller}/{action}/{id}",
                                                                new MvcRouteHandler())
                                                            ,
                                                            RouteHandler = new MvcRouteHandler()
                                                        },
                                                };

            customersController.ControllerContext.RouteData.Values.Add("language", "German");
            customersController.ControllerContext.RouteData.Values.Add("controller", "Article");
            customersController.ControllerContext.RouteData.Values.Add("action", "Index");
            customersController.ControllerContext.RouteData.Values.Add("id", "");
            var model = (...);
            string actual = RenderStuff.RenderPartialViewToString(viewName, model, customersController.ControllerContext);
            (...)
        }

对于模拟，我使用了 Rhino.Mocks 和来自 Stephenwalther.com 的 MvcFakes

Answer 1

我认为 this thread可以帮助你，你必须模拟 ViewEngine 然后模拟 FindPartialView 调用。