单元测试动作过滤器-如何模拟ViewResult

我在SO上搜索了一下,看起来这个问题经常被问到。我已经能够让mock工作了,而且我还能够执行OnActionExecuted(),没有任何问题。这是我的单元测试。注释行是失败的,我肯定我没有嘲笑正确的类型。

        //Arrange
        //var viewResult = new ViewResult();
        var filterContextMock = new Mock<ActionExecutedContext>();
        var routeData = new RouteData();
        var httpContextMock = new Mock<HttpContextBase>();

        routeData.Values["data"] = "Mock data";
        var requestContext = new RequestContext(httpContextMock.Object, routeData);

        var controller = new FakeController();
        controller.ControllerContext = new ControllerContext(requestContext, controller);

        filterContextMock.Setup(f => f.RouteData).Returns(routeData);
        filterContextMock.Setup(f => f.Controller).Returns(controller);
        //filterContextMock.Setup(f => f.Result).Returns(viewResult);

        //Act
        var wrapFilterAttribute = new WrapFilterAttribute();
        wrapFilterAttribute.OnActionExecuted(filterContextMock.Object);

这是我的动作过滤器。

public class WrapFilterAttribute : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        var view = (ViewResultBase)filterContext.Result;

        if (view != null)
        {
            BaseViewModel viewModel = (BaseViewModel)view.ViewData.Model ?? new BaseViewModel();
            viewModel.Wrap = new WrapperFactory().GetWrap();
        }

        base.OnActionExecuted(filterContext);
    }
}

非常感谢!