Mocking the Controller Context using Rhino Mock

When using ASP.NET MVC 5, its easy to write unit tests around the framework due to the various abstractions provided. Stephen Walther provides a good overview of the different objects. Whenever you need to interact with the request, response, session or browser, the following objects can be mocked using your mocking framework of choice:

• HttpRequestBase
• HttpResponseBase
• HttpSessionBase
• HttpBrowserCapabilitiesBase

Here of some examples using of mocking the various classes using Rhino Mock:

Mocking the Controller Context (MVC)

public void SetUpControllerContext()
{
    // Setup the controller context plumbing
    var httpContext = MockRepository.GenerateMock<HttpContextBase>();
    var httpRequest = MockRepository.GenerateMock<HttpRequestBase>();
    var httpResponse = MockRepository.GenerateMock<HttpReponseBase>();
    var browserMock = MockRepository.GenerateMock<HttpBrowserCapabilitiesBase>();
 
    // Set the required test values
    httpContext.Stub(h => h.Request.Browser).Return(browserMock);
    httpContext.Stub(h => h.Request).Return(httpRequest);
 
    // Now create the system under test
    var repository = MockRepository.GenerateMock<Repository>();
    var controller = new CustomerController(repository);
    controller.ControllerContext = new ControllerContext(httpContext, new RouteData(), _controller);
           
    controller.Create();
   
    // Assertions
}

Mocking the Controller Context (Web API)

var controller = new TestController();
var config = new HttpConfiguration();
var request = new HttpRequestMessage(HttpMethod.Get, "http://localhost/api/test");
var route = config.Routes.MapHttpRoute("default", "api/{controller}/{id}");
var routeData = new HttpRouteData(route, new HttpRouteValueDictionary { { "controller", "test" } });

controller.ControllerContext = new HttpControllerContext(config, routeData, request);
controller.Request = request;
controller.Request.Properties[HttpPropertyKeys.HttpConfigurationKey] = config;

Mocking the Identity and Principal

public void SetUpHttpRequestUser()
{
    // Setup the controller context plumbing
    var httpContext = MockRepository.GenerateStub<HttpContextBase>();
    var identity = MockRepository.GenerateStub<IIdentity>();          
    var principal = MockRepository.GenerateStub<IPrincipal>();
                                   
    // Set the required test values
    identity.Stub(i => i.Name).Return("TestUser");
    principal.Stub(u => u.Identity).Return(identity);
    httpContext.User = new GenericPrincipal(new GenericIdentity(String.Empty), new string[0]);
;
           
    // Now create the system under test
    var repository = MockRepository.GenerateMock<Repository>();
    var controller = new CustomerController(repository);
    var controller.ControllerContext = new ControllerContext(httpContext, new RouteData(), _controller);
                                   
    controller.Create();
   
    // Assertions
}

Mocking the Session State

public void SetUpSession()
{
    // Arrange
    var httpContext = MockRepository.GenerateStub<HttpContextBase>();
    var httpSession = MockRepository.GenerateStub<HttpSessionStateBase>();
                                       
    httpContext.Stub(h => h.Session).Return(httpSession);
    mock.Setup(p => p.HttpContext.Session).Returns(mockSession.Object);

    // Now create the system under test
    var repository = MockRepository.GenerateMock<Repository>();
    var controller = new CustomerController(repository);
    var controller.ControllerContext = new ControllerContext(httpContext, new RouteData(), _controller);
 
    controller.Create();

    // Assertions
    Assert.AreEqual("testuser1", controller.HttpContext.Session["Username"]);
}