TypeError: can only concatenate str (not "PostGenerationMethodCall") to str

[toshism]

When using factory.PostGenerationMethodCall on a factory I get the type error in the title.

The factory I'm working with is a django user model. Simple example:

class UserFactory(factory.django.DjangoModelFactory):
    email = factory.Sequence(lambda n: "user-{0}@example.com".format(n))
    password = factory.PostGenerationMethodCall("set_password", ["password"])
    first_name = fuzzy.FuzzyText(length=20)
    last_name = fuzzy.FuzzyText(length=20)

    class Meta:
        model = "users.User"
        django_get_or_create = ("email",)

register(UserFactory)

Attempting to use that factory as a fixture will throw:

env/lib/python3.7/site-packages/pytest_factoryboy/plugin.py:83: in evaluate
    self.execute(request, function, deferred)
env/lib/python3.7/site-packages/pytest_factoryboy/plugin.py:65: in execute
    self.results[model][attr] = function(request)
env/lib/python3.7/site-packages/pytest_factoryboy/fixture.py:273: in deferred
    declaration.call(instance, step, context)
env/lib/python3.7/site-packages/factory/declarations.py:743: in call
    return method(*args, **kwargs)
env/lib/python3.7/site-packages/django/contrib/auth/base_user.py:98: in set_password
    self.password = make_password(raw_password)
env/lib/python3.7/site-packages/django/contrib/auth/hashers.py:78: in make_password
    return hasher.encode(password, salt)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <django.contrib.auth.hashers.MD5PasswordHasher object at 0x7f1fa3759cd0>, password = <factory.declarations.PostGenerationMethodCall object at 0x7f1fa47ff390>, salt = 'XXXXXXXXX'

    def encode(self, password, salt):
        assert password is not None
        assert salt and '$' not in salt
>       hash = hashlib.md5((salt + password).encode()).hexdigest()
E       TypeError: can only concatenate str (not "PostGenerationMethodCall") to str

env/lib/python3.7/site-packages/django/contrib/auth/hashers.py:508: TypeError

The error stems from

pytest-factoryboy/pytest_factoryboy/fixture.py

Line 75 in 37e46da

if isinstance(value, factory.declarations.PostGeneration):

.

Changing that check to something like:

        if isinstance(value, factory.declarations.PostGeneration) or isinstance(
                value, factory.declarations.PostGenerationMethodCall
            ):

Seems to fix the issue. I haven't looked at this closely though so not sure if that's the best solution.

possibly relevant versions:
pytest-factoryboy==2.0.3
django==2.2.6
factory-boy==2.12.0
pytest-django==3.6.0