MVC Get View HTML output in Test Method [closed]

How can I get generated HTML (View) in my Test Method?

I have the following:

Controller:

public ActionResult Index()
{
    ViewBag.Message = "Welcome to ASP.NET MVC!";

    return View();
}

View:

@{
    ViewBag.Title = "Home Page";
}

<h2>@ViewBag.Message</h2>
<p>
    To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website">http://asp.net/mvc</a>.
</p>

Test:

   [TestMethod]
    public void HomeControllerReturnsView()
    {
        // Arrange
        var controller = new HomeController();

        // Act
        var result = controller.Index() as ViewResult;

        using (StringWriter sw = new StringWriter())
        {
            ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(controller.ControllerContext, "Home");
            ViewContext viewContext = new ViewContext(controller.ControllerContext, viewResult.View, controller.ViewData, controller.TempData, sw);
            viewResult.View.Render(viewContext, sw);

            var test = sw.GetStringBuilder().ToString();
        }
    }

FYI: when i run this in debug controller.HttpContext and controller.RouteData are null. thanks