– needed in the HttpContext to allow FormsAuthentication.SignOut() to execute

I am trying to write a unit test for our log out method. Among other things it FormsAuthentication.SignOut(). However, it throws a System.NullReferenceException.

I've created a mock; HttpContext (using Moq), but it is obviously missing something.

My mock context contains:

  • A mocked HttpRequestBase on Request
  • A mocked HttpResponseBase on Response
  • With a HttpCookieCollection on Request.Cookies and another on Response.Cookies
  • A mocked IPrincipal on User

I am aware I could go the wrapper route and inject an empty FormsAuth wrapper object in it's place, but I would really like to avoid the 3 additional files just to fix one line of code. That and I am still curious for an answer

So my question is "What is needed in the HttpContext to allow FormsAuthentication.SignOut() to execute."

Best Solution

The NullReferenceException in this case is actually being thrown by the call:


You can test this assertion by calling:


...which will also return the NullReferenceException. Contrary to the accepted answer, if you attempt to call:

CookielessHelperClass.UseCookieless(current, false, CookieMode)

...from the immediate window, this will return without error.

You can fix the exception like this:

HttpContext.Current.Request.Browser = new HttpBrowserCapabilities() { Capabilities = new Dictionary<string, string> { { "supportsEmptyStringInCookieValue", "false" } } };

...and the FormsAuthentication.SignOut() call will now succeed.