Faking Http Context with Moq and Mvc - moq

Question

I’m trying to fake http context to test a Controller. My environment is MVC 3 and Moq 4.
So far I have tried a few options including:
a.
var searchController = new MySearchController(_mockResolver.Object.Resolve<IConfiguration>());
var mockContext = new Mock<ControllerContext>();
searchController.ControllerContext = mockContext.Object;
var result = searchController.Render();
b.
var searchController = new MopSearchController(_mockResolver.Object.Resolve<IConfiguration>());
searchController.MockControllerContext();
var result = searchController.Render();
public static class MockHttpHelper
{
public static Mock<HttpContextBase> MockControllerContext(
this Controller controller, string path = null)
{
var mockHttpCtx = MockHttpHelper.MockHttpContext(path);
var requestCtx = new RequestContext(mockHttpCtx.Object, new RouteData());
var controllerCtx = new ControllerContext(requestCtx, controller);
controller.ControllerContext = controllerCtx;
return mockHttpCtx;
}
public static Mock<HttpContextBase> MockHttpContext(string path)
{
var mockHttpCtx = new Mock<HttpContextBase>();
var mockReq = new Mock<HttpRequestBase>();
mockReq.SetupGet(x => x.RequestType).Returns("GET");
mockReq.SetupGet(req => req.Form).Returns(new NameValueCollection());
mockReq.SetupGet(req => req.QueryString).Returns(new NameValueCollection());
mockHttpCtx.SetupGet(x => x.Request).Returns(mockReq.Object);
return mockHttpCtx;
}
}
Neither of these work, I get the exception below. Can anyone point me in the direction of a working example? I’ve seen quite a few questions on the net around the same topic, but given the date (posts from 2008-2010) and MVC version (i.e. 1 and 2) I feel like I’m missing something / or trying to mock more than I need to in MVC3.
System.NullReferenceException : Object reference not set to an instance of an object.
at System.Web.Mvc.ChildActionValueProviderFactory.GetValueProvider(ControllerContext controllerContext)
at System.Web.Mvc.ValueProviderFactoryCollection.<>c__DisplayClassc.<GetValueProvider>b__7(ValueProviderFactory factory)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList(IEnumerable`1 source)
at System.Web.Mvc.ValueProviderFactoryCollection.GetValueProvider(ControllerContext controllerContext)
at System.Web.Mvc.Controller.TryUpdateModel(TModel model)
Thanks

Answer 1

Yes, all you were really missing, as you've noted, was setting the Controller's ValueProvider. Even though you're using this controller with a Get action but no Post action, the Controller still gets its ValueProvider instantiated upon creation, so you need to do the same thing in your test scenario. Here's the base class that I use when testing my controllers. I use NBehave's NUnit wrapper for unit testing, so ignore the SpecBase reference if you wish
public abstract class MvcSpecBase<T> : SpecBase<T> where T : Controller
{
protected T Controller { get; set; }
protected string RelativePath = string.Empty;
protected string AbsolutePath = string.Empty;
protected void InitialiseController(T controller, NameValueCollection collection, params string[] routePaths)
{
Controller = controller;
var routes = new RouteCollection();
RouteConfig.RegisterRoutes(routes);
var httpContext = ContextHelper.FakeHttpContext(RelativePath, AbsolutePath, routePaths);
var context = new ControllerContext(new RequestContext(httpContext, new RouteData()), Controller);
var urlHelper = new UrlHelper(new RequestContext(httpContext, new RouteData()), routes);
Controller.ControllerContext = context;
Controller.ValueProvider = new NameValueCollectionValueProvider(collection, CultureInfo.CurrentCulture);
Controller.Url = urlHelper;
}
}
Then, in your test, create your controller and then call this line:
InitialiseController(controller, new FormCollection());