How to mock the Request on Controller in ASP.Net MVC?

Question

I have a controller in C# using the ASP.Net MVC framework

public class HomeController:Controller{
  public ActionResult Index()
    {
      if (Request.IsAjaxRequest())
        { 
          //do some ajaxy stuff
        }
      return View("Index");
    }
}

I got some tips on mocking and was hoping to test the code with the following and RhinoMocks

var mocks = new MockRepository();
var mockedhttpContext = mocks.DynamicMock<HttpContextBase>();
var mockedHttpRequest = mocks.DynamicMock<HttpRequestBase>();
SetupResult.For(mockedhttpContext.Request).Return(mockedHttpRequest);

var controller = new HomeController();
controller.ControllerContext = new ControllerContext(mockedhttpContext, new RouteData(), controller);
var result = controller.Index() as ViewResult;
Assert.AreEqual("About", result.ViewName);

However I keep getting this error:

Exception System.ArgumentNullException: System.ArgumentNullException : Value cannot be null. Parameter name: request at System.Web.Mvc.AjaxRequestExtensions.IsAjaxRequest(HttpRequestBase request)

Since the Request object on the controller has no setter. I tried to get this test working properly by using recommended code from an answer below.

This used Moq instead of RhinoMocks, and in using Moq I use the following for the same test:

var request = new Mock<HttpRequestBase>();
// Not working - IsAjaxRequest() is static extension method and cannot be mocked
// request.Setup(x => x.IsAjaxRequest()).Returns(true /* or false */);
// use this
request.SetupGet(x => x.Headers["X-Requested-With"]).Returns("XMLHttpRequest");

var context = new Mock<HttpContextBase>();
context.SetupGet(x => x.Request).Returns(request.Object);
var controller = new HomeController(Repository, LoginInfoProvider);
controller.ControllerContext = new ControllerContext(context.Object, new RouteData(), controller);
var result = controller.Index() as ViewResult;
Assert.AreEqual("About", result.ViewName);

but get the following error:

Exception System.ArgumentException: System.ArgumentException : Invalid setup on a non-overridable member: x => x.Headers["X-Requested-With"] at Moq.Mock.ThrowIfCantOverride(Expression setup, MethodInfo methodInfo)

Again, it seems like I cannot set the request header. How do I set this value, in RhinoMocks or Moq?

Answer 1

Using Moq:

var request = new Mock<HttpRequestBase>();
// Not working - IsAjaxRequest() is static extension method and cannot be mocked
// request.Setup(x => x.IsAjaxRequest()).Returns(true /* or false */);
// use this
request.SetupGet(x => x.Headers).Returns(
    new System.Net.WebHeaderCollection {
        {"X-Requested-With", "XMLHttpRequest"}
    });

var context = new Mock<HttpContextBase>();
context.SetupGet(x => x.Request).Returns(request.Object);

var controller = new YourController();
controller.ControllerContext = new ControllerContext(context.Object, new RouteData(), controller);

UPDATED:

Mock Request.Headers["X-Requested-With"] or Request["X-Requested-With"] instead of Request.IsAjaxRequest().

Answer 2

For anyone using NSubstitute I was able to modify the above answers and do something like this... (where Details is the Action method name on the controller)

 var fakeRequest = Substitute.For<HttpRequestBase>();
        var fakeContext = Substitute.For<HttpContextBase>();
        fakeRequest.Headers.Returns(new WebHeaderCollection { {"X-Requested-With", "XMLHttpRequest"}});
        fakeContext.Request.Returns(fakeRequest);
        controller.ControllerContext = new ControllerContext(fakeContext, new RouteData(), controller);
        var model = new EntityTypeMaintenanceModel();

        var result = controller.Details(model) as PartialViewResult;

        Assert.IsNotNull(result);
        Assert.AreEqual("EntityType", result.ViewName);

Answer 3

Here is a working solution using RhinoMocks. I've based it on a Moq solution I found at http://thegrayzone.co.uk/blog/2010/03/mocking-request-isajaxrequest/

public static void MakeAjaxRequest(this Controller controller)
{
        MockRepository mocks = new MockRepository();

        // Create mocks
        var mockedhttpContext = mocks.DynamicMock<HttpContextBase>();
        var mockedHttpRequest = mocks.DynamicMock<HttpRequestBase>();

        // Set headers to pretend it's an Ajax request
        SetupResult.For(mockedHttpRequest.Headers)
            .Return(new WebHeaderCollection() {
                {"X-Requested-With", "XMLHttpRequest"}
            });

        // Tell the mocked context to return the mocked request
        SetupResult.For(mockedhttpContext.Request).Return(mockedHttpRequest);

        mocks.ReplayAll();

        // Set controllerContext
        controller.ControllerContext = new ControllerContext(mockedhttpContext, new RouteData(), controller);
}

Answer 4

Is AjaxRequest is an extension method. So you can do it the following way using Rhino:

    protected HttpContextBase BuildHttpContextStub(bool isAjaxRequest)
    {
        var httpRequestBase = MockRepository.GenerateStub<HttpRequestBase>();   
        if (isAjaxRequest)
        {
            httpRequestBase.Stub(r => r["X-Requested-With"]).Return("XMLHttpRequest");
        }

        var httpContextBase = MockRepository.GenerateStub<HttpContextBase>();
        httpContextBase.Stub(c => c.Request).Return(httpRequestBase);

        return httpContextBase;
    }

    // Build controller
    ....
    controller.ControllerContext = new ControllerContext(BuildHttpContextStub(true), new RouteData(), controller);

Answer 5

Looks like you are looking for this,

 var requestMock = new Mock<HttpRequestBase>();
 requestMock.SetupGet(rq => rq["Age"]).Returns("2001");

Usage in Controller :

 public ActionResult Index()
 {
        var age = Request["Age"]; //This will return 2001
 }

Answer 6

You need to mock HttpContextBase and put it into your ControllerContext property, like that:

controller.ControllerContext = 
new ControllerContext(mockedHttpContext, new RouteData(), controller);

Answer 7

To make IsAjaxRequest() to return false during Unit test you need to setup Request Headers as well as request collection value both in your test method as given below:

_request.SetupGet(x => x.Headers).Returns(new System.Net.WebHeaderCollection { { "X-Requested-With", "NotAjaxRequest" } });
_request.SetupGet(x=>x["X-Requested-With"]).Returns("NotAjaxRequest");

The reason for setting up both is hidden in implementation of IsAjaxRequest() which is given below:

public static bool IsAjaxRequest(this HttpRequestBase request)<br/>
{ 
    if (request == null)
    {
        throw new ArgumentNullException("request");
    }
    return ((request["X-Requested-With"] == "XMLHttpRequest") || ((request.Headers != null) && (request.Headers["X-Requested-With"] == "XMLHttpRequest")));
}

It uses both request Collection and header this is why we need to create setup for both Header and Request Collection.

this will make the request to return false when it is not a ajax request. to make it return true you can do the following:

_httpContext.SetupGet(x => x.Request["X-Requested-With"]).Returns("XMLHttpRequest");

Answer 8

I found other way to add a HttpRequestMessage object into your request during Web API as follow

[Test]
public void TestMethod()
{
    var controllerContext = new HttpControllerContext();
    var request = new HttpRequestMessage();
    request.Headers.Add("TestHeader", "TestHeader");
    controllerContext.Request = request;
    _controller.ControllerContext = controllerContext;

    var result = _controller.YourAPIMethod();
    //Your assertion
}