Django 5.1b1: GenericForeignKey exception

[james-certn]

I understand that this is happening with a beta release of Django, but I thought important to report for future compatibility. Maybe something in Django needs to change, maybe something in model-bakery (or maybe our code!).

With a model like this:

class MyModel(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.UUIDField()
    content_object = GenericForeignKey("content_type", "object_id")

... and a test using model-bakery like this:

 my_obj = baker.make(MyModel)

... we are seeing a pytest output that looks like the following:

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
../venv/lib/python3.11/site-packages/model_bakery/baker.py:142: in make
    return baker.make(
../venv/lib/python3.11/site-packages/model_bakery/baker.py:401: in make
    return self._make(**params)
../venv/lib/python3.11/site-packages/model_bakery/baker.py:466: in _make
    self.model_attrs[field.name] = self.generate_value(
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <model_bakery.baker.Baker object at 0xffff623e29d0>
field = <django.contrib.contenttypes.fields.GenericForeignKey: content_object>
commit = True

    def generate_value(self, field: Field, commit: bool = True) -> Any:  # noqa: C901
        """Call the associated generator with a field passing all required args.
    
        Generator Resolution Precedence Order:
        -- `field.default` - model field default value, unless explicitly overwritten during baking
        -- `attr_mapping` - mapping per attribute name
        -- `choices` -- mapping from available field choices
        -- `type_mapping` - mapping from user defined type associated generators
        -- `default_mapping` - mapping from pre-defined type associated
           generators
    
        `attr_mapping` and `type_mapping` can be defined easily overwriting the
        model.
        """
        is_content_type_fk = False
        if BAKER_CONTENTTYPES:
            is_content_type_fk = isinstance(field, ForeignKey) and issubclass(
                self._remote_field(field).model, contenttypes_models.ContentType
            )
        # we only use default unless the field is overwritten in `self.rel_fields`
        if field.has_default() and field.name not in self.rel_fields:
            if callable(field.default):
                return field.default()
            return field.default
        elif field.name in self.attr_mapping:
            generator = self.attr_mapping[field.name]
        elif field.choices:
            generator = random_gen.gen_from_choices(field.choices)
        elif is_content_type_fk:
            generator = self.type_mapping[contenttypes_models.ContentType]
        elif generators.get(field.__class__):
            generator = generators.get(field.__class__)
        elif field.__class__ in self.type_mapping:
            generator = self.type_mapping[field.__class__]
        else:
>           raise TypeError(
                f"field {field.name} type {field.__class__} is not supported by baker."
            )
E           TypeError: field content_object type <class 'django.contrib.contenttypes.fields.GenericForeignKey'> is not supported by baker.

../venv/lib/python3.11/site-packages/model_bakery/baker.py:725: TypeError

Versions

• Python: 3.11
• Django: 5.1b1
• Model Bakery 1.18.2

To be clear, the following works with Django 5.0.x, same python/bakery versions.

[amureki]

Hey @james-certn !

Thank you for the report!
It is indeed to keep the future compatibility, I will take a look at this.

[amureki]

Okay, I've found a suspect commit:
django/django@6002df0

The signature changed a bit, we would need to adapt our detection of GFK.

[amureki]

Once again, thank you for the report.
This unveiled an older bug in GFK handling.
It was fixed and official Django 5.1 support was released in 1.19.0:
https://pypi.org/project/model-bakery/1.19.0/