django_get_or_create with SubFactory

Description

The django_get_or_create feature is working well when the concerned Factory is used as a BaseFactory but not when it’s used as a SubFactory When used as a SubFactory, the following error occurs : AttributeError: type object 'CurrencyFactory' has no attribute '_original_params'

To Reproduce

With the below code, the error will occur randomly when the same currency code/name is used.

To reproduce it systematically, just change the PairFactory with the following line :

base_currency = factory.SubFactory(CurrencyFactory, name="Bitcoin")

It will force the IntegrityError in the Currency Factory, so it will try the get_or_create feature. And then call the PairFactory() two times and voila.

E           AttributeError: type object 'CurrencyFactory' has no attribute '_original_params'

../../../.cache/pypoetry/virtualenvs/belfort-backend-KmGKt2wB-py3.10/lib/python3.10/site-packages/factory/django.py:151: AttributeError

Model / Factory code

# Models
class Currency(models.Model):
    name = models.CharField(max_length=100, unique=True)
    symbol = models.CharField(max_length=20, unique=True)

class Pair(models.Model):
    base_currency = models.ForeignKey(
        Currency, on_delete=models.CASCADE, related_name="pairs_as_base"
    )
    quoted_currency = models.ForeignKey(
        Currency, on_delete=models.CASCADE, related_name="pairs_as_quoted"
    )

# Factories
class CurrencyFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = "Currency"
        django_get_or_create = ("name", "symbol")

    name = factory.Faker("cryptocurrency_name")
    symbol = factory.Faker("cryptocurrency_code")

class PairFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = "Pair"

    base_currency = factory.SubFactory(CurrencyFactory)
    quoted_currency = factory.SubFactory(CurrencyFactory)

Notes

I believe this is linked to the _generate() method which is not called for SubFactory, while the _original_params is set only in this method.

[foarsitter]

Ok, took some time to provide a failing testcase (forgive me for the bad naming).

Do you agree that the problem can be solved by initiating the class attribute _original_params as an empty dict {}?

[foarsitter]

Thanks for providing some context! Checking for None will be the fix over here then at this moment I think. Raising the IntegrityError gives the user enough information to fix it I suppose (at least it would have give me).