Unit test c#: Create Fake Httpcontext to bypass Null exception for User object

 Microsoft Visual studio Test Framework

Requirement: Nuget package Moq 4.13.0.0 (or later)

Settings in visual studio: Menu->Tools->Options ->Debugging->General

Tick "Use Managed Compatibility Mode"

Code: (copied from stackoverflow)

Step 1: 

Create a new class FakeHttpContext and paste the below code. Change the Returns value to whatever user name you need.

public static class FakeHttpContext

    {

        public static void SetFakeContext(this Controller controller)

        {

            var httpContext = MakeFakeContext();

            ControllerContext context =

            new ControllerContext(

            new RequestContext(httpContext,

            new RouteData()), controller);

            controller.ControllerContext = context;

        }

        private static HttpContextBase MakeFakeContext()

        {

            var context = new Mock<HttpContextBase>();

            var request = new Mock<HttpRequestBase>();

            var response = new Mock<HttpResponseBase>();

            var session = new Mock<HttpSessionStateBase>();

            var server = new Mock<HttpServerUtilityBase>();

            var user = new Mock<IPrincipal>();

            var identity = new Mock<IIdentity>();

            context.Setup(c => c.Request).Returns(request.Object);

            context.Setup(c => c.Response).Returns(response.Object);

            context.Setup(c => c.Session).Returns(session.Object);

            context.Setup(c => c.Server).Returns(server.Object);

            context.Setup(c => c.User).Returns(user.Object);

            user.Setup(c => c.Identity).Returns(identity.Object);

            identity.Setup(i => i.IsAuthenticated).Returns(true);

            identity.Setup(i => i.Name).Returns("sanjeeb");

            return context.Object;

        }

    }

Step 2: 

Initialize the Fakehttpcontext in test initialize function. 

FakeHttpContext.SetFakeContext(usersController);