如何对 System.Web.Mvc.Controller 的 Initialize() 方法进行单元测试？

Question

我想对 Controller 对象的 Initialize 方法进行单元测试。 Initialize() 方法基本上是从请求对象的 cookie 集合中提取玩家的 ID，并从数据库中检索当前的玩家对象。然后播放器对象存储在控制器对象的 CurrentPlayer 属性中。我有以下用于单元测试的代码。这个测试基本上是为控制器的Index()方法写的：

[Test]
public void Index_ReturnsJsonResult ()
{
   var _gameRepositoryMock = GameRepositoryCreator.Create (5);

   var _formsAuthenticationMock = new Mock<IFormsAuthentication> ();

   var _chooseOpponentController = new ChooseOpponentController (_gameRepositoryMock.Object, _formsAuthenticationMock.Object);


    var cookie = new HttpCookie (cookieName);
    cookie.Value = player.PlayerID + "_encrypted";

    var cookies = new HttpCookieCollection ();
    cookies.Add (cookie);

    var httpRequestMock = new Mock<HttpRequestBase> ();
    httpRequestMock.Setup (x => x.Cookies).Returns (cookies);
    httpRequestMock.Setup (x => x.IsAuthenticated).Returns (true);

    var httpContextMock = new Mock<HttpContextBase> ();
    httpContextMock.Setup (x => x.Request).Returns (httpRequestMock.Object);

    var rd = new RouteData ();
    rd.Values.Add ("action", "Index");
    rd.Values.Add ("controller", "ChooseOpponent");

    var requestContext = new RequestContext (httpContextMock.Object, rd); 

    _formsAuthenticationMock.Setup (x => x.Decrypt (cookie.Value)).Returns (player.PlayerID + "");   

    (_chooseOpponentController as IController).Execute (requestContext);

    Assert.IsNotNull (_chooseOpponentController.CurrentPlayer);

    ... // test other things for the Index () method
}

Index()方法声明为：

 [Authorize, SavePlayerStatus(Order=2), CommitChanges(Order=1)]
 public ActionResult Index ()
 { ... }

Initialize () 方法成功执行，但之后我收到异常消息：“对象引用未设置为对象的实例。”，堆栈跟踪如下所示：

at System.Web.Compilation.BuildManager.GetCacheKeyFromVirtualPath(VirtualPath virtualPath, Boolean& keyFromVPP)
at System.Web.Compilation.BuildManager.GetVPathBuildResultFromCacheInternal(VirtualPath virtualPath, Boolean ensureIsUpToDate)
at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate)
at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate)
at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound)
at System.Web.Mvc.BuildManagerWrapper.System.Web.Mvc.IBuildManager.FileExists(String virtualPath)
at System.Web.Mvc.BuildManagerViewEngine.FileExists(ControllerContext controllerContext, String virtualPath)
at System.Web.Mvc.VirtualPathProviderViewEngine.GetPathFromGeneralName(ControllerContext controllerContext, List`1 locations, String name, String controllerName, String areaName, String cacheKey, String[]& searchedLocations)
at System.Web.Mvc.VirtualPathProviderViewEngine.GetPath(ControllerContext controllerContext, String[] locations, String[] areaLocations, String locationsPropertyName, String name, String controllerName, String cacheKeyPrefix, Boolean useCache, String[]& searchedLocations)
at System.Web.Mvc.VirtualPathProviderViewEngine.FindView(ControllerContext controllerContext, String viewName, String masterName, Boolean useCache)
at System.Web.Mvc.ViewEngineCollection.<>c__DisplayClassc.<FindView>b__b(IViewEngine e)
at System.Web.Mvc.ViewEngineCollection.Find(Func`2 lookup, Boolean trackSearchedPaths)
at System.Web.Mvc.ViewEngineCollection.FindView(ControllerContext controllerContext, String viewName, String masterName)
at System.Web.Mvc.ViewResult.FindView(ControllerContext context)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<>c__DisplayClass1e.<InvokeActionResultWithFilters>b__1b()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)

感谢任何帮助。

Answer 1

通过调用Execute，您实际上是在调用整个MVC 管道。这包括尝试进入磁盘并查找视图文件的视图查找逻辑。失败的部分是没有正确初始化的 ASP.NET 编译系统。

对于单元测试，您执行的太多了。我会编写 2 个测试：一个验证 Index 方法是否正确，另一个验证 Initialize 方法是否正确。其他一切（Initialize 在操作方法之前被调用的事实等）都是 MVC 管道，您无需担心。