Fixture set up and tear down in pytest

July 25, 2024

• https://docs.pytest.org/en/latest/how-to/fixtures.html#teardown-cleanup-aka-fixture-finalization

 
@pytest.fixture(scope="session", autouse=True)
def fixt_datastore(
    fixt_datastore_settings: DatabaseConnectionSettings,
) -> Generator[Datastore, None, None]:
    datastore = create_datastore(fixt_datastore_settings)
 
    with datastore._session_factory.get_session() as session:
        engine = session.get_bind()
        assert engine.url.drivername == "sqlite"
 
    datastore.create_all_models()
    yield datastore
    datastore.drop_all_models()

Autouse:

• scope mismatch (especially with tmp_path fixture) can cause issues, use fixture factories to avoid this
  • ScopeMismatch: You tried to access the function scoped fixture tmp_path with a session scoped request object, involved factories:
  • https://github.com/tortoise/tortoise-orm/issues/638
  • https://docs.pytest.org/en/6.2.x/fixture.html#autouse-order

Fixture factory:

Sharing in-memory sqlite database across tests:

• https://stackoverflow.com/questions/32681761/how-can-i-attach-an-in-memory-sqlite-database-in-python/32681822#32681822
• when you use datastore as a fixture, it will be created and destroyed for each test that uses it, the tables won't be present across tests, but we can attach an in-memory database to the sqlite engine to share the tables across tests