testing from a common test fixture; inconsistent results - unit-testing

Question

I have two test fixtures that have a common parent. Although the tests involve SQLite/NHib type of stuff, which are usually a bit of a at first, there is something I don't understand about NUnit that I'm hoping will help be fix these tests.
The good news is that if I run (via TestDriven.Net) both the subclassed TestFixtures without selecting the common parent, all tests succeed. But if I include the common parent in the run, I get failures (presumably because my NHib session has been disposed or lost it's binding).
Can anyone explain why the two tests succeed on their own but not with
the parent, and if there is someway to enforce the successful
behavior?
Cheers,
Berryl
public class ActivityTestFixture : GreenQueryOnlySQLiteTestFixture
{
protected IProjectDao _projectDao;
protected IDao<Account> _accountDao;
protected override void OnFixtureSetUp()
{
base.OnFixtureSetUp();
_projectDao = DataFactory.GetProjectDao(_sessionFactoryContext.SessionFactory);
_accountDao = DataFactory.GetAccountDao(_sessionFactoryContext.SessionFactory);
}
}
[TestFixture]
public class AccountDaoTests : ActivityTestFixture
{
[Test]
public void FindAll_IsEquivalentToSeeds() {
IList<Account> found;
using (var tx = _session.BeginTransaction()) {
found = _accountDao.FindAll();
tx.Commit();
}
found.AssertUnsavedValueSequenceEqual(ActivitySubjectSeeds.AllAccounts.ToAr ray());
}
}
[TestFixture]
public class ProjectDaoTests : ActivityTestFixture
{
[Test]
public void FindAll_IsEquivalentToSeeds()
{
IList<Project> found;
using (var tx = _session.BeginTransaction())
{
found = _projectDao.FindAll();
tx.Commit();
}
found.AssertUnsavedValueSequenceEqual(ActivitySubjectSeeds.Projects.ToArray ());
}
}

Answer 1

Not sure what the error that you're getting is, but it's likely because you have some kind of static fields in the GreenQueryOnlySQLiteTestFixture class. The way NUnit works is that a fixture lives for the lifetime of the tests inside of it. So it is only created once for all of the tests. This is different from xUnit which lives for the lifetime of one test.
Without seeing the entire implementation it's hard to see what is wrong. However, you can remove the TestFixtureAttribute from your parent fixture since it does not appear to have any tests anyway.