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How to pass specific UserContext in unit testing of controller action

I have the following controller action
[Route(ActionName.Create)]
public async Task<ActionResult> Create()
{
....
if (!UserContext.Roles.HasFlag(GroupsEnum.Admin))
{
throw new UnauthorizedAccessException("Permission Denied");
}
...
}
I have following in xxxxControllerTests.cs
[TestMethod]
public async Task Can_Request_Create()
{
ViewResult result = (ViewResult)await MockController.Object.Create();
...
...
}
when I run the unit test I get unauthorized access exception raised. How can pass UserContext while mockController, so controller action will be executed with specific user context?

Normally when you're instantiating the Controller you're testing, you can initialize it like this:
var controllerToTest = new MyController() {
ControllerContext = new ControllerContext {
HttpContext = //assign mock context,
UserContext = //assign mock context
}
};
var result = controllerToTest.Create();
However this line of code makes me think you're testing an already mocked controller:
ViewResult result = (ViewResult)await MockController.Object.Create();
The .Object call makes me think you have a Mock<MyController> in there and that's not right. You're not testing your own controller.

You should Mock your dbContext.
[https://stackoverflow.com/questions/54219742/mocking-ef-core-dbcontext-and-dbset][1]

How to mock the controller

I have a method in a controller that check's the user's role to see which page the user should be redirected.
I am trying to do unit testing for the following code
public class HomeController: Controller {
//...
public IActionResult Home()
{
if (User.IsInRole("Administrators")
{
return RedirectToAction("/administrator");
}
else
{
return RedirectToAction("/user");
}
}
//...other actions
}

That mock setup is incorrect; you actually cannot mock members of concrete classes (unless they're virtual). But thankfully that's no big deal here, because you don't need to use a mock. Generally speaking the following is a working way of dealing with HttpContext testing:
[Test]
public async Task HomeReturnsNotNull()
{
var controller = new HomeController();
var controllerCtx = new ControllerContext()
{
HttpContext = new DefaultHttpContext()
{
User = new ClaimsPrincipal(new ClaimsIdentity(new[] { new Claim(ClaimTypes.Role, "Administrators") }))
}
};
controller.ControllerContext = controllerCtx;
ActionResult index = (ActionResult)controller.Home();
Assert.IsNotNull(index);
}
But it's often more comfortable to rely on some abstractions of your own, instead of calling HttpContext members directly.
Took the liberty to change 'admin' to 'Administrators', because I noticed a discrepancy between the value in the test and the value in the controller action.
This way the IsInRole() check in the controller action should execute properly, which should be useful in the other tests (since in this one it seems you're just checking against null).

Mocking a controller to test ViewEngine inside an Area - nullreference and RouteData

I have an Area in my MVC site. This area has the typical Controller/Model/View setup.
As a controller I have the following code:
public class DocumentCreatorController : Controller
{
// GET: Templates/DocumentCreator
public ActionResult OfferTemplate(BaseDocumentViewModel data)
{
return this.Pdf(nameof(OfferTemplate), data, "File.pdf");
}
}
The method this.Pdf does a couple of stuff, but the interesting is it comes down to the ViewEngine call:
var viewResult = ViewEngines.Engines.FindPartialView(controllerContext, partialViewName);
Here I call the FindPartialView with a ControllerContext and a PartialViewName. My PartialViewName comes from the nameof(OfferTemplate) from the controller action OfferTemplate. I think the controllercontext is my challenge.
My challenge:
When I want to set this up in a unit test (using Moq), I have the following code based on pages such as Mocking The RouteData Class in System.Web.Routing for MVC applications and Mocking Asp.net-mvc Controller Context:
[TestMethod]
public void OfferTemplate()
{
var ctr = SetupControllerWithContext();
}
private static DocumentCreatorController SetupControllerWithContext()
{
var routeData = new RouteData();
routeData.Values.Add("controller", "DocumentCreatorController");
routeData.Values.Add("action", "OfferTemplate");
var request = new Mock<HttpRequestBase>();
request.Expect(r => r.HttpMethod).Returns("GET");
var mockHttpContext = new Mock<HttpContextBase>();
mockHttpContext.Expect(c => c.Request).Returns(request.Object);
var controllerContext = new ControllerContext(mockHttpContext.Object
, routeData, new Mock<ControllerBase>().Object);
DocumentCreatorController ctr = new DocumentCreatorController();
ctr.ControllerContext = controllerContext;
return ctr;
}
Which gives the following error:
Eesy.Websites.Api.Tests.Controllers.DocumentCreatorControllerTest.OfferTemplate
threw exception:
System.NullReferenceException: Object reference not set to an instance of an object.
This I don't understand.
My folder setup:
Debug image on ControllerContext on calling the FindPartialView:
Anyone have an idea?
Is it because I setup the RouteData wrong?

You are trying to mock and test framework code. Abstract that functionality out into code you control so you can test in isolation if needed.
Currently the action and by extension the controller is tightly coupled to external 3rd party dependencies. If the goal was to test the controller action flow in isolation then it is advised to abstract out the 3rd party PDF generation so that it can be mocked for easier testability.
public interface IDocumentService {
ActionResult ToPdf(Controller arg1, string arg2, object arg3, string arg4);
}
The controller would explicitly depend on this abstraction via constructor injection.
public class DocumentCreatorController : Controller {
private readonly IDocumentService render;
DocumentCreatorController(IDocumentService render) {
this.render = render;
}
// GET: Templates/DocumentCreator
public ActionResult OfferTemplate(BaseDocumentViewModel data) {
return render.ToPdf(this, nameof(OfferTemplate), data, "File.pdf");
}
}
So now to test the controller's pdf generation process you need only mock your abstraction.
[TestMethod]
public void OfferTemplate() {
//Arrange
var serviceMock = new Mock<IDocumentService>();
//...setup mock for use case
var controller = new DocumentCreatorController(serviceMock.Object);
var data = new BaseDocumentViewModel {
//...
};
//Act
var actual = controller.OfferTemplate(data);
//Assert
//...assert behavior
}
The actual implementation of the service would encapsulate the actual functionality and would be registered with the dependency injection container along with the abstraction.
To test the actual generation you would need to do an integration test which is another topic.

Abstraction layer between Controller and View

I am trying to create another layer between my controller and my view so that I can pass different versions of a view to a user based on their "client ID" which would be the company to which they belong.
I have the following code:
public class HomeController : Controller
{
//
// GET: /Home/
public ActionResult Index()
{
// set client
var client = new Client();
client.Id = Guid.NewGuid();
client.Name = "Foo";
// set user
var user = new User();
user.Id = Guid.NewGuid();
user.ClientId = client.Id;
user.Name = "Foo";
return ViewRenderer.RenderView("AddComplete", client);
}
}
My ViewRenderer class looks like this:
public static class ViewRenderer
{
public static ViewResult RenderView(string view, Guid clientId)
{
string viewName = GetViewForClient(view, clientId);
return Controller.View(view);
}
public static string GetViewForClient(string view, Guid clientId)
{
// todo: logic to return view specific to the company to which a user belongs...
}
}
The problem is, the line return Controller.View(view); in RenderView(string view, Guid clientId) gives me the error:
System.Web.Mvc.Controller.View()' is inaccessible due to its
protection level
I am interested to know how I can resolve this error or if there is a better way to do what I am trying to do, which is to display different versions of a view which are specific to the respective company to which a user belongs.
Edit: Another option I was kicking around in my head...
Is there a way to override the View() method such that I can prepend it with a directory name, for example, a user who belongs to "Acme Co." would call the same controller action as everyone else like View("MyView") but the method would actually be calling View("AcmeCo/MyView") however, I don't actually write that code in my controller, it's just derived from the user's client ID property.

You can just replace the view engine instead of adding another abstraction.
Write your own View engine (here is how to start off with a RazorViewEngine)
public class ByIdRazorViewEngine : RazorViewEngine
{
protected override IView CreateView(ControllerContext controllerContext,
string viewPath, string masterPath)
{
var id = // get something from controller context controllerContext
var newViewPath = CalculateViewPathFromId(id);
return base.CreateView(controllerContext, newViewPath, masterPath);
}
And register it in Global.asax.cs:
protected void Application_Start()
{
ViewEngines.Engines.Clear();
ViewEngines.Engines.Add(new ByIdRazorViewEngine());
}

The View() method is a protected member. You can only access it from within a derived type, such as your HomeController class. Plus you're trying to access it as a static method.
You can create a base Controller that exposes your specialized view logic. For the sake of illustration, I'm going to call it DynamicViewControllerBase
public class HomeController : DynamicViewControllerBase
{
//
// GET: /Home/
public ActionResult Index()
{
// set client
var client = new Client();
client.Id = Guid.NewGuid();
client.Name = "Foo";
// set user
var user = new User();
user.Id = Guid.NewGuid();
user.ClientId = client.Id;
user.Name = "Foo";
return RenderView("AddComplete", client);
}
}
public class DynamicViewControllerBase : Controller
{
protected ViewResult RenderView(string view, Guid clientId)
{
string viewName = GetViewForClient(view, clientId);
return View(view);
}
// Unless you plan to use methods and properties within
// the instance of `Controller`, you can leave this as
// a static method.
private static string GetViewForClient(string view, Guid clientId)
{
// todo: logic to return view...
}
}

If all you want to have is the company name prefixed to your controllers, apply the RoutePrefix attribute on to your controller.
Example:
[RoutePrefix(#"{company}")]
public partial class HomeController : Controller
{
}
And in your RouteConfig file,
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
// Make sure this line is added
routes.MapMvcAttributeRoutes();
}
Since your users must be authenticated to sign in to their accounts, once they've authenticated them selves you can either:
Store a cookie on your users machine with the name of their company
Make calls to your database on each request to retrieve this information
Make use of ViewData[]
etc..
Once you have the name of their company, you can construct the urls with that name.
Example:
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Login(LoginViewModel model)
{
// ... authenticate user etc
// Redirect to
// foo.com/abc/home
return this.RedirectToAction("Index", "Home", new { company = "abc" });
}
If you're trying to work a way around this, I doubt you'll be able to as the web request first comes through a route, and the route decides which controller/action is executed, but to know the company name your action needs to execute to retrieve.

Unit Testing Controller Actions that call IsAjaxRequest()

Some of my controller actions need to respond with different ViewResults depending whether or not they were called by an AJAX request. Currently, I'm using the IsAjaxRequest() method to check for this. When this method is called during a unit test, it throws an ArgumentNullException because the HTTP context is missing.
Is there a way to mock/fake this call? Or is this a sign I should be checking for an AJAX request another way?

Would it help if you provide a Test Double for the HTTP Context?
This can be done like this:
var httpCtxStub = new Mock<HttpContextBase>();
var controllerCtx = new ControllerContext();
controllerCtx.HttpContext = httpCtxStub.Object;
sut.ControllerContext = controllerCtx;
where sut represents the System Under Test (SUT), i.e. the Controller you wish to test.
This example uses Moq.

Using moq library in MVC test projects
[TestClass]
public class HomeControllerTest
{
[TestMethod]
public void Index()
{
// Arrange
HomeController controller = new HomeController();
controller.injectContext();
// controller.injectContext(ajaxRequest: true);
// Act
ViewResult result = controller.Index() as ViewResult;
// Assert
Assert.IsNotNull(result);
}
}
public static class MvcTestExtensions
{
public static void injectContext(this ControllerBase controller, bool ajaxRequest = false)
{
var fakeContext = new Mock<ControllerContext>();
fakeContext.Setup(r => r.HttpContext.Request["X-Requested-With"])
.Returns(ajaxRequest ? "XMLHttpRequest" : "");
controller.ControllerContext = fakeContext.Object;
}
}