A simple method to mock out an HttpContext using NSubstitute for unit testing API Controllers in C#

HttpContextFaker.cs

using System;
using NSubstitute;
using Stage.Data;
using System.IO;
using System.Linq;
using System.Security.Principal;
using System.Web;

namespace FakerTools 
{
	public static class HttpContextFaker
	{
        public static void FakeGenericPrincipalContext()
        {
            // You could also replace this with a custom identity as needed
            var identity = Substitute.For<IIdentity>();
            HttpContext.Current = new HttpContext(new HttpRequest("", "http://tempuri.org", ""), new HttpResponse(new StringWriter()));
            HttpContext.Current.User = new GenericPrincipal(identity, null);
        }
	}
}