Allow SQLAlchemy factories to be committed on create

It seems like the general consensus is that one should only flush the current session during a test case, and roll back on each tear down. Due to the nature of my testing setup it is more convenient to commit instead of flush on create. Have you considered adding a meta flag similar to force_flush that would allow the session to be committed?

for example:

class SQLAlchemyModelFactory(base.Factory):
    """Factory for SQLAlchemy models. """

    _options_class = SQLAlchemyOptions
    class Meta:
        abstract = True

    @classmethod
    def _create(cls, model_class, *args, **kwargs):
        """Create an instance of the model, and save it to the database."""
        session = cls._meta.sqlalchemy_session
        obj = model_class(*args, **kwargs)
        session.add(obj)
+       if cls._meta.force_commit:
+          session.commit()
        elif cls._meta.force_flush:
            session.flush()
        return obj

overriding SQLAlchemyModelFactory._create is my current solution. Any suggestions on how to properly have Factories be committed on creation is welcome! Thanks!

[aalvrz]

@zyskowsk I’ve been following this thread because I am experiencing a similar issue:

class MyModel(Base):
    created_at = Column(DateTime, nullable=False, default=datetime.utcnow)


class MyFactory(factory.alchemy.SQLAlchemyModelFactory):
    class Meta:
        model = MyModel
        sqlalchemy_session_persistence = "commit"


def my_test():
    a = MyFactory()
    b = MyFactory()
    c = MyFactory()

    assert not a.created_at == b.created_at  # Fails

All those objects will have the same value for created_at. I am using commit for sqlalchemy_session_persistence and the assertion fails. However if I use flush then the datetimes will be different. Not realy sure what strategy I should use? From what I understand in this thread, your intention was to use commit strategy.

[zyskowsk]

Hey @jeffwidman thanks for the quick response! enabling force_flush is not exactly what I am looking for. Let me try and better explain my situation, I may be missing something simple.

The situation I am running into is that I have server-side defaults on all of my models for created_at and updated_at. These defaults are set with db.func.now() in postgres, which is defined by the start time of the last transaction.

This means that if I only ever call session.flush(), even if I issue an INSERT followed by an UPDATE, on the same row, the updated_at value will remain the same until the current transaction is committed.

I am hoping to test that when I update an object through an api, the updated_at value changes. However, when I create a factory with force_flush enabled, and then issue an update on that row late, the updated_at column still reflects the start time of the open transaction.

For this reason I want Factory.create call to issue a commit on the session, not just a flush.