NHibernate ISession.Refresh fails test

See more:

C#

C#4.0

NUnit

NHibernate

Hello everyone,

I'm seeing some strange behaviour in NHibernate, in particular that ISession.Refresh doesn't always do what it says on the tin when I call it. My code:

public TEntity Refresh(TEntity entity)
{
   Contract.Requires<ArgumentNullException>(entity != null, "entity");

   try
   {
       //this.Session holds the ISession
       this.Session.Refresh(entity);

       return entity;
   }
   catch (Exception ex)
   {
       throw new RepositoryException("", ex);
   }
}

Unit test I'm calling it from:

[Test]
public void ShouldRefresh()
{
   var customer = new Customer { CustomerId = "ALFKI" };

   customer = this.repository.Refresh(customer);

   Assert.IsNotEmpty(customer.CompanyName);
}

What's strange is that if I run the unit test by itself, it passes having refreshed all the properties I didn't bother to fill in. If I run the test in a test run after other tests, it fails.

I'm only initialising the ISession once per test run, which seems to be the key here. With a clean ISession it works fine, with one that's already been used for other stuff it fails. As I intend to control the lifecycle of the ISession from a single composition root, reinitialising the ISession isn't an option. Therefore, my question is: how can I get ISession.Refresh to work without reinitialising the ISession?