How to Mock/Stub or simply ignore HttpRequest when unit testing [duplicate]

Answer 1

Make DeviceDetection a concrete dependency of DemoController:

public class DemoController : Controller
{
    private readonly ICommonOperationsRepository _commonRepo;
    private readonly DeviceDetection dd;

    public DemoController (
        ICommonOperationsRepository commonRepo,
        DeviceDetection dd)
    {
        _commonRepo = commonRepo;
        this.dd = dd;
    }

    public ActionResult Default()
    {
        var model = new DemoModel();
        try
        {
            this.dd.DetectDevice();
            model.ListTopListing.AddRange(_commonRepo.GetListings());
        }
        catch (Exception ex)
        {
            ExceptionHandler objErr = new ExceptionHandler(ex, "DemoController .Default()\n Exception : " + ex.Message);
            objErr.LogException();
        }
        return View(model);
    }
}

This should enable you to create an instance of DemoController without relying on the Request property:

var sut = new DemoController(someStupRepository, new DeviceDetection("foo"));

You can do this in e.g. a unit test.

When you compose DemoController in your application, you pass in request.ServerVariables["HTTP_X_REWRITE_URL"].ToString() to DeviceDetection. You can get the request variable from the requestContext argument of CreateController.