How do I unit test a controller action that uses t

问题:

I have a controller action that automatically redirects to a new page if the user is already logged in (User.Identity.IsAuthenticated). What is the best way to write a unit test for this scenario to ensure that the redirect takes places?

回答1:

I've been using the following Mocks with Moq to allow setting up various conditions in my unit tests. First, the HttpContextBase mock:

    public static Mock<HttpContextBase> GetHttpContextMock(bool isLoggedIn)
    {
        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 principal = AuthenticationAndAuthorization.GetPrincipleMock(isLoggedIn);

        context.SetupGet(c => c.Request).Returns(request.Object);
        context.SetupGet(c => c.Response).Returns(response.Object);
        context.SetupGet(c => c.Session).Returns(session.Object);
        context.SetupGet(c => c.Server).Returns(server.Object);
        context.SetupGet(c => c.User).Returns(principal.Object);

        return context;
    }

Every property that might provide a useful Mock is set up in here. That way, if I need to add something like a referrer, I can just use:

Mock.Get(controller.Request).Setup(s => s.UrlReferrer).Returns(new Uri("http://blah.com/");

The "GetPrincipleMock" method is what sets up the user. It looks like this:

    public static Mock<IPrincipal> GetPrincipleMock(bool isLoggedIn)
    {
        var mock = new Mock<IPrincipal>();

        mock.SetupGet(i => i.Identity).Returns(GetIdentityMock(isLoggedIn).Object);
        mock.Setup(i => i.IsInRole(It.IsAny<string>())).Returns(false);

        return mock;
    }

    public static Mock<IIdentity> GetIdentityMock(bool isLoggedIn)
    {
        var mock = new Mock<IIdentity>();

        mock.SetupGet(i => i.AuthenticationType).Returns(isLoggedIn ? "Mock Identity" : null);
        mock.SetupGet(i => i.IsAuthenticated).Returns(isLoggedIn);
        mock.SetupGet(i => i.Name).Returns(isLoggedIn ? "testuser" : null);

        return mock;
    }

Now, my controller setups in the tests look like this:

var controller = new ProductController();
var httpContext = GetHttpContextMock(true); //logged in, set to false to not be logged in

ControllerContext controllerContext = new ControllerContext(httpContext.Object, new RouteData(), controller);
controller.ControllerContext = controllerContext;

It's a little bit of verbose setup, but once you have everything in place, testing a variety of conditions becomes a lot easier.

回答2:

That's not the simplest thing to do, but it can be done. The User property simply delegates to Controller.HttpContext.User. Both are non-virtual read-only properties, so you can't do anything about them. However, Controller.HttpContext delegates to ControllerBase.ControllerContext which is a writable property.

Therefore, you can assign a Test Double HttpContextBase to Controller.ControllerContext before exercising your System Under Test (SUT). Using Moq, it would look something like this:

var user = new GenericPrincipal(new GenericIdentity(string.Empty), null);
var httpCtxStub = new Mock<HttpContextBase>();
httpCtxStub.SetupGet(ctx => ctx.User).Returns(user);

var controllerCtx = new ControllerContext();
controllerCtx.HttpContext = httpCtxStub.Object;

sut.ControllerContext = controllerCtx;

Then invoke your action and verify that the return result is a RedirectResult.

This test utilizes the implicit knowledge that when you create a GenericIdentity with an empty name, it will return false for IsAuthenticated. You could consider making the test more explicit by using a Mock<IIdentity> instead.