Problems with unit tests and NHibernate

krugs525 · **Posted:** Tue Feb 20, 2007 2:33 pm

I'm having some problems with unit testing while using NHibernate. Here's the basic flow of my tests:

1) Create some objects
2) Save the objects
3) Put the object in a state so that it won't pass business rules and verify that the validation rules are working
4) Try and delete all of the objects that I had saved to the database and restore everything to the way it was before I ran the test

The problem happens when I do step 4... in the process of putting everything back, I'm executing a query. But before NHibernate attempts to execute the query, it tries to flush all dirty objects in the session, which fails because some of the objects that I was testing are not valid (I have implemented IInterceptor and I do my validation in OnFlushDirty()).

So my question is what can I do here? It seems that I can't do anything using NHibernate if I have an object that is invalid in the session because it's going to fail every time it tries to flush it, which will happen any time I do anything.

I know about the ISession.FlushMode property, but that doesn't help me out because the problem still exists, even though you might not run into it as much.

Any thoughts?

Jon

onevextchuck · **Posted:** Tue Feb 20, 2007 6:24 pm

In most of our tests, we open a session and begin a transaction in the SetUp. In our TearDown, we rollback the transaction and close the session.

This seems like it will work for you since you don't want the invalid objects in the database.

In those few instances where we are actually testing that the database is performing a task correctly, we either leave the transaction management out of the SetUp/TearDown, or we just make sure to leave the transaction and session in a state where the TearDown can still close the session safely.

jnapier · **Joined:** Sat Sep 10, 2005 3:46 pm **Posts:** 178

If you are using sql 2005 you can use TransactionScope to have your tests rolled back automatically:

Code:

IOrgRepository orgRepository = IocContainer.Resolve<IOrgRepository>();

using(TransactionScope scope = new TransactionScope()){
            //create a new org 
            Organization newOrg = new Organization(Functions.RandomString(10));

            //add the org into the Repository
            orgRepository.Add(newOrg);
            
            //clear the session so that we can retrieve the item from the data repository
            ((NHibernateOrgRepository)orgRepository).SessionContext.CurrentSession.Clear(); 

            //retrieve the org from the data store
            Organization reconstitutedOrg = orgRepository.GetById(newOrg.Id);
            
            //verify that retieved org is equal to the new org
            Assert.AreEqual(newOrg.Id, reconstitutedOrg.Id);
         }

You'll have to change the connection release mode to not use the aggresive release style to avoid the transaction rolling up to msdtc.

grennis · **Joined:** Sat Mar 25, 2006 9:16 am **Posts:** 150

Evict the invalid objects from the session.

Session.Evict()