Testing Security Link Demands with R#

This is more just a reference for me or anyone else that may stumble across this.

I had a set of Controller tests that I needed to set a mock object to Thread.CurrentPrincipal so I could test PrincipalPermission attributes. Off the bat I would just happily set Thread.CurrentPrincipal to my mocked user and everything worked fine.

When I ran the full suite of tests including all of my SqlCE Nhibernate tests I saw that NHibernate was throwing a TypeInitializationException from NHibernate.Cfg.Environment. After quite awhile of debugging I found that the data tests would only fail when I ran my Controller tests in conjunction with the data tests. After even more time I remembered about the Thread.CurrentPrincipal.

Normally you probably wouldn’t even notice a problem. It seemed as if though that when R# was trying to load the NHibernate Session it somehow didn’t have permission because Visual Studios Principal was changed to a mock object! An ephiany ensued followed by kicking myself in the rear.

To fix it, I just saved the CurrentPrincipal to an IPrincipal instance and set it back in the TearDown of my Controller test like so:

private IPrincipal _oldPrincipal;

[SetUp]
public void Setup()
{
    _oldPrincipal = Thread.CurrentPrincipal;
    Thread.CurrentPrincipal = _user;
}

[TearDown]
public void TearDown()
{
    Thread.CurrentPrincipal = _oldPrincipal;
}

Hopefully this post helps someone from falling into the same trap. Cheers!