Factory.build fixtures about pytest-factoryboy HOT 8 OPEN

@olegpidsadnyi any thoughts on this? A sensible defacto way of retrieving build/unsaved models would replace a bunch of stuff in the suite I'm currently working on – and I'd rather not write a fixture for each model – is there a way to do this already or would adding a pre/suffixed fixture name be the way to go here?

from pytest-factoryboy.

A few further thoughts

• A decorator would be passable... but I'd rather make the default not saving than making people go to more /effort/ to write db-free tests
• Automatically toggling this based on whether the db fixture (or /a/ db fixture) is included would be neat but kind of crazy, and I have no idea how you'd do that... that'd negate the need for pre/suffixing though which would be cool
• An alternative to the above could be a nodb fixture or something but again crazy no idea how

A suffix or a decorator to adjust how the factory works for the test in question seems like the way to go but I am wondering if we can do better

from pytest-factoryboy.

@stevelacey it is more like what kind of base factory are you using, right? What kind of ORM is it in your case. I guess there's a difference between build and create, but if you have a non-db model, what kind of difference does it make?

Could you please describe your setup?

from pytest-factoryboy.

from pytest-factoryboy.

@olegpidsadnyi ☝️

from pytest-factoryboy.

This is very good idea. I try another case, byt this is not work. Normally in FactoryBoy we have strategy in class Meta. If I set BUILD_STRATEGY and usage fixture_factory and call to them, this fixture connect with my db. This is not intuitive..

register(MyModel)

def test_something(my_model_factory):
    my_model_factory()   # <- this call db
    my_model_factory.build().   # <- this not call db

from pytest-factoryboy.

from pytest-factoryboy.

Wouldn't the following work? Generate these fixtures:

@pytest.fixture
def derive_factory_strategy():  # or call it factory_strategy_strategy ;)
    def derive(factory_class):
        return factory_class._meta.strategy
    return derive

@pytest.fixture
def {factory_name}__strategy(derive_factory_strategy):
    strategy = derive_factory_strategy(factory_class)
    ...

@pytest.yield_fixture
def {factory_name}({factory_name}__strategy):
    # - Setting TheFactory._meta.strategy is basically all use_strategy does.
    #   I'm not using it as I have to get the _meta.strategy so that
    #   I can reset it later and there's no public function for that that I know of.
    # - You could also use the pytest builtin monkeypatch.setattr to temporarily
    #    change the strategy.
    #   (It's necessary to change it back as the factory is the actual factory
    #   class, which isn't isolated across tests)
    default_strategy = foo_factory._meta.strategy
    foo_factory._meta.strategy = {factory_name}__strategy
    yield foo_factory
    # yield_fixture catches exceptions for us, no need for try: finally:
    foo_factory._meta.strategy = default_strategy

The user can now globally override the desired strategy, e.g. to derive from presence of a db fixture the user could write:

@pytest.fixture
def derive_factory_strategy(request):
    def derive(factory_class):
        if 'db' in request.fixturenames:
            return factory.CREATE_STRATEGY
        else:
            return factory.BUILD_STRATEGY

If a user wants to override a single FooFactory's strategy, they can override the foo_factory__strategy fixture.

from pytest-factoryboy.