HttpContextFactory + Test

ExampleController.cs

public class ExampleController : Controller
{
    private readonly IConfigurationReader _configurationReader;
    private readonly IHttpContextFactory _httpContextFactory;

    public MaintenanceController(IConfigurationReader configurationReader, IHttpContextFactory httpContextFactory)
    {
        _configurationReader = configurationReader;
        _httpContextFactory = httpContextFactory;
    }

    public ActionResult Index()
    {
        var users = _configurationReader.GetMaintenanceUsers();
        var roles = _configurationReader.GetMaintenanceRoles();
        if (users.IndexOf(_httpContextFactory.GetContext().User.Identity.Name, StringComparison.CurrentCultureIgnoreCase) > 0 ||
            roles.Split(',').Any(s => _httpContextFactory.GetContext().User.IsInRole(s))) //if user name
        {
            return View();
        }
        return new EmptyResult();
    }

}

ExampleControllerTests.cs

public class ControllerTests
{
    [TestFixture]
    public class when_getting_index
    {
        [Test]
        public void then_should_return_view()
        {
            // Arrange
            var configurationReader = new Mock<IConfigurationReader>();
            configurationReader.Setup(reader => reader.GetMaintenanceRoles()).Returns(string.Empty);
            configurationReader.Setup(reader => reader.GetMaintenanceUsers()).Returns(string.Empty);

            var identity = new Mock<IIdentity>();
            identity.Setup(identity1 => identity1.Name).Returns(string.Empty);

            var principal = new Mock<IPrincipal>();
            principal.Setup(principal1 => principal1.Identity).Returns(identity.Object);

            var httpContextBase = new Mock<HttpContextBase>();
            httpContextBase.Setup(@base => @base.User).Returns(principal.Object);

            var httpContextFactory = new Mock<IHttpContextFactory>();
            httpContextFactory.Setup(factory => factory.GetContext()).Returns(httpContextBase.Object);

            var controller = new MaintenanceController(configurationReader.Object, httpContextFactory.Object);

            // Act
            var viewResult = controller.Index();

            // Assert
            Assert.That(viewResult, Is.Not.Null);
        }
    } 
}

HttpContextFactory.cs

// ReSharper disable ClassNeverInstantiated.Global
public class HttpContextFactory : IHttpContextFactory
// ReSharper restore ClassNeverInstantiated.Global
{
    public HttpContextBase GetContext()
    {
        if(HttpContext.Current == null) throw new InvalidOperationException("HttpContext is null");

        return new HttpContextWrapper(HttpContext.Current);
    }
}

HttpContextFactoryTests.cs

public class HttpContextFactoryTests
{
    [TestFixture]
    public class when_creating_httpcontext
    {
        [Test]
        public void then_should_return_type_of_http_context()
        {
            // Arrange
            var factory = new HttpContextFactory();

            // Act // Assert
            Assert.Throws<InvalidOperationException>(() => factory.GetContext());
        }
    }
}

IHttpContextFactory.cs

public interface IHttpContextFactory
{
    HttpContextBase GetContext();
}