Data migrations: preserve data between fixture tests

Hi,

I'm working on a app with default data migrations (some models are populated with the RunPython migration method, ie. default users, related models for select...).

I'm working on a test with data sets declares in a list of dicts, using a fixture with the request.param magic.

My fixture data looks like:

FIXTURE_DATA = [{"name": "Foo"}, {"name": "Bar"}...]

@pytest.fixture(scope="session", params=FIXTURE_DATA)
def data(request)
    return request.param

@pytest.mark.django_db
def test_01_data(data):
    # Make the stuff...
    pass

Then I try to run the test, with a single fixture yielding my test data, the whole content of the database is freed between each fixture run:

• First data dict instance: OK
• Second data dict instance: The database structure is in place, but RunPython migrated data are flushed... my test cannot continue.

I'm using a "droppable" sqlite file in /dev/shm, I'ld like to explore the content of the database after the tests - is it possible ?

Thanks !

Start by reproducing the shown parametrized pytest fixture with @pytest.mark.django_db, Django RunPython migrations, and the SQLite database in /dev/shm. Trace when the database is reset between fixture parameters and compare that with the requested post-test database inspection. Done means documenting or implementing a supported way to preserve migrated data between runs without breaking test isolation.