programmatic login with .net membership provider

Question

I'm trying to unit test a piece of code that needs a currently logged in user in the test. Using the .Net 2.0 Membership Provider, how can I programmatically log in as a user for this test?

Solution 1

I've found it most convenient to create a disposable class that handles setting and resetting Thread.CurrentPrincipal.

    public class TemporaryPrincipal : IDisposable {
        private readonly IPrincipal _cache;

        public TemporaryPrincipal(IPrincipal tempPrincipal) {
            _cache = Thread.CurrentPrincipal;
            Thread.CurrentPrincipal = tempPrincipal;
        }

        public void Dispose() {
            Thread.CurrentPrincipal = _cache;
        }
    }

In the test method you just wrap your call with a using statement like this:

using (new TemporaryPrincipal(new AnonymousUserPrincipal())) {
    ClassUnderTest.MethodUnderTest();
}

Solution 2

Does your code actually need a user logged in via ASP.NET, or does it just need a CurrentPrincipal? I don't think you need to programmatically log in to your site. You can create a GenericPrincipal, set the properties you need, and attach it to, for example Thread.CurrentPrincipal or a mocked HttpContext. If your code actually needs RolePrincipal or something then I would change the code to be less coupled to ASP.NET membership.

Comments

[ddc0660]

I need the call to Membership.GetUser() to return the currently logged in user.

[Kevin Gauthier]

Don't call Membership.GetUser() directly in the class under test. Supply the class with an IGetUser in creation, use it in place of Membership.GetUser(), then make a mock implementation of IGetUser for testing.