Last Updated: February 25, 2016

Common ASP.NET MVC controller mocking scenarios

I don't know how many times I keep needing to mock out parts of an ASP.NET MVC's controller context. In fact - it's a requirement if you're doing any ASP.NET MVC Web Application.

That's kewl! So lets look at some common helpers I use in my unit tests.

FYI: I'm using Moq as my mock testing framework

Overall Info.

Everything comes back to the ControllerContext property, on a Controller instance. As such, I like to see if we can pass as much stuff into a single method which returns a Mocked instance of this.

public static Mock<ControllerContext> MockControllerContext(Mock<HttpSessionStateBase> mockSessionStateBase = null)
{
 var mockControllContext = new Mock<ControllerContext>();
 if (mockSessionStateBase == null)
 {
 mockSessionStateBase = MockSessionStateBase();
 }

 mockControllContext.Setup(x => x.HttpContext.Session).Returns(mockSessionStateBase.Object);

 return mockControllContext;
}

Scenario: Referencing the Session.

Problem:

public RedirectResult RedirectToAuthenticationProvider(RedirectToAuthenticationProviderInputModel inputModel)
{
 // Which provider are we after?
 var settings = AuthenticationServiceSettingsFactory.GetAuthenticateServiceSettings(inputModel.ProviderKey);

 // We need to remember the state for some XSS protection.
 Session[SessionStateKey] = Guid.NewGuid();
 settings.State = Session[SessionStateKey].ToString();

 // Grab the Uri we need redirect to.
 var uri = _authenticationService.RedirectToAuthenticationProvider(settings);

 // Redirect!
 return Redirect(uri.AbsoluteUri);
}

Setup:

We can have multiple Session Key/Values in a single Context. As such, this method can be called multiple times. If you provide a specific key/value, then we set it up, with that. Otherwise, accept anything :)

public static Mock<HttpSessionStateBase> MockSessionStateBase(string sessionStateKey = null,
 object sessionStateValue = null)
{
 var mockSessionStateBase = new Mock<HttpSessionStateBase>();
 if (string.IsNullOrEmpty(sessionStateKey) ||
 sessionStateValue == null)
 {
 mockSessionStateBase.Setup(x => x[It.IsAny<string>()]).Returns("some-fake-state");
 }
 else
 {
 mockSessionStateBase.Setup(x => x[sessionStateKey]).Returns(sessionStateValue);
 }

 return mockSessionStateBase;
}

Usage:

var mockSession = ControllerMocks.MockSessionStateBase();
var authenticationController = new AuthenticationController(authenticationService)
 {
 ControllerContext =
 ControllerMocks.MockControllerContext(mockSession).Object
 };