How to add claims in a mock ClaimsPrincipal

Question

I am trying to unit test my controller code which gets the information from the ClaimsPrincipal.Current. In the controller code I

public class HomeController {
    public ActionResult GetName() {
        return Content(ClaimsPrincipal.Current.FindFirst("name").Value);
    }
}

And I am trying to mock my ClaimsPrincipal with claims but I still don't have any mock value from the claim.

// Arrange
IList<Claim> claimCollection = new List<Claim>
{
    new Claim("name", "John Doe")
};

var identityMock = new Mock<ClaimsIdentity>();
identityMock.Setup(x => x.Claims).Returns(claimCollection);

var cp = new Mock<ClaimsPrincipal>();
cp.Setup(m => m.HasClaim(It.IsAny<string>(), It.IsAny<string>())).Returns(true);
cp.Setup(m => m.Identity).Returns(identityMock.Object);

var sut = new HomeController();

var contextMock = new Mock<HttpContextBase>();
contextMock.Setup(ctx => ctx.User).Returns(cp.Object);

var controllerContextMock = new Mock<ControllerContext>();
controllerContextMock.Setup(con => con.HttpContext).Returns(contextMock.Object);
controllerContextMock.Setup(con => con.HttpContext.User).Returns(cp.Object);

sut.ControllerContext = controllerContextMock.Object;

// Act
var viewresult = sut.GetName() as ContentResult;

// Assert
Assert.That(viewresult.Content, Is.EqualTo("John Doe"));

The viewresult.Content is empty as I run the unit test. Any help if I can add the mock claim. Thanks.

Answer 1

First, you are missing this line in your test:

Thread.CurrentPrincipal = cp.Object;  

(and then cleaning it up in TearDown).

Second, as @trailmax mentioned, mocking principal objects is impractical. In your case, ClaimsPrincipal.FindFirst (according to decompiled source) looks into private fields of its instance, that's the reason mocking didn't help.

I prefer using two simple classes that allow me to unit test claims-based functionality:

    public class TestPrincipal : ClaimsPrincipal
    {
        public TestPrincipal(params Claim[] claims) : base(new TestIdentity(claims))
        {
        }
    }

    public class TestIdentity : ClaimsIdentity
    {
        public TestIdentity(params Claim[] claims) : base(claims)
        {
        }
    }

then your test shrinks down to:

    [Test]
    public void TestGetName()
    {
        // Arrange
        var sut = new HomeController();
        Thread.CurrentPrincipal = new TestPrincipal(new Claim("name", "John Doe"));

        // Act
        var viewresult = sut.GetName() as ContentResult;

        // Assert
        Assert.That(viewresult.Content, Is.EqualTo("John Doe"));
    }

and it now passes, I've just verified.