Merge pull request #849 from bckohan/bakery

Document model-bakery integration and test considerations

Author: bckohan

docs/advanced.rst

@@ -390,6 +390,12 @@ Restrictions & Caveats
     base row. If you must delete manually, ensure you also delete the corresponding row from the
     base table.
 
+*   There will be problems if the :class:`~django.contrib.contenttypes.models.ContentType` cache
+    becomes out of sync with the database. This can especially happen in tests. You should ensure
+    that the cache is cleared (:meth:`~django.contrib.contenttypes.models.ContentTypeManager.clear_cache`)
+    whenever this happens. In tests this happens when if :django-admin:`flush` is called by the teardown
+    sequence in :class:`~django.test.TransactionTestCase`.
+
 .. old links:
     - http://code.djangoproject.com/wiki/ModelInheritance
     - http://lazypython.blogspot.com/2009/02/second-look-at-inheritance-and.html

docs/changelog/index.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+v4.10.4 (2026-01-19)
+--------------------
+
+* Documented `model-bakery integration and test considerations <https://github.com/jazzband/django-polymorphic/issues/849>`_
+
 v4.9.1, v4.10.3 (2026-01-15)
 ----------------------------
 

docs/conf.py

@@ -285,6 +285,7 @@
     "django-guardian": ("https://django-guardian.readthedocs.io/en/stable", None),
     "django-reversion": ("https://django-reversion.readthedocs.io/en/stable", None),
     "django-extra-views": ("https://django-extra-views.readthedocs.io/en/stable", None),
+    "model-bakery": ("https://model-bakery.readthedocs.io/en/stable", None),
 }
 
 # autodoc settings

docs/integrations/djangorestframework.rst docs/integrations/drf.rstdocs/integrations/djangorestframework.rst renamed to docs/integrations/drf.rst

@@ -26,10 +26,11 @@ For the integration examples on this page, we use the following polymorphic mode
     :language: python
     :linenos:
 
+
 .. _django-django-guardian-support:
 
-django-guardian
----------------
+:pypi:`django-guardian`
+-----------------------
 
 .. versionadded:: 1.0.2
 
@@ -50,8 +51,8 @@ available in the `django-guardian documentation
 
 .. _django-extra-views-support:
 
-django-extra-views
-------------------
+:pypi:`django-extra-views`
+--------------------------
 
 .. versionadded:: 1.1
 
@@ -105,8 +106,8 @@ The template for rendering the formset:
 
 .. _django-reversion-support:
 
-django-reversion
-----------------
+:pypi:`django-reversion`
+------------------------
 
 Support for :pypi:`django-reversion` works as expected with polymorphic models. We just need to
 do two things:
@@ -148,8 +149,55 @@ This makes sure both the reversion template is used, and the breadcrumb is corre
 polymorphic model using the :templatetag:`breadcrumb_scope`
 tag.
 
+.. _model-bakery:
 
-.. toctree::
+:pypi:`model-bakery`
+--------------------
+
+:pypi:`model-bakery` does not work without without special configuration for polymorphic models
+because it overrides the :attr:`~polymorphic.models.PolymorphicModel.polymorphic_ctype` field.
+The best option to make it work in all cases is to `supply a custom Baker
+<https://model-bakery.readthedocs.io/en/latest/how_bakery_behaves.html#customizing-baker>`_ class
+that fills in all fields except :attr:`~polymorphic.models.PolymorphicModel.polymorphic_ctype`:
+
+.. code-block:: python
+    :linenos:
+    :caption: yoursite/tests/baker.py
+
+    from polymorphic.models import PolymorphicModel
+    from model_bakery import baker
+
+
+    class PolymorphicAwareBaker(baker.Baker):
+        """
+        Our custom model baker ignores the polymorphic_ctype field on all polymorphic
+        models - this allows the base class to set it correctly.
+        See https://github.com/python/pythondotorg/issues/2567
+        """
+
+        def get_fields(self):
+            fields = super().get_fields()
+            if issubclass(self.model, PolymorphicModel):
+                fields = {field for field in fields if field.name != "polymorphic_ctype"}
+            return fields
 
-   djangorestframework
 
+Then in your test settings file:
+
+.. code-block:: python
+
+    BAKER_CUSTOM_CLASS = "yoursite.tests.baker.PolymorphicAwareBaker"
+
+You may also simply pass the correct :class:`~django.contrib.contenttypes.models.ContentType`
+instance to the :attr:`~polymorphic.models.PolymorphicModel.polymorphic_ctype` field when creating
+polymorphic model instances with ``make()``
+
+
+Other Integrations
+------------------
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+
+   drf

docs/integrations/index.rst

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "django-polymorphic"
-version = "4.10.3"
+version = "4.10.4"
 description = "Seamless polymorphic inheritance for Django models."
 readme = "README.md"
 license = "BSD-3-Clause"

pyproject.toml

@@ -19,7 +19,7 @@
 Seamless Polymorphic Inheritance for Django Models
 """
 
-VERSION = "4.10.3"
+VERSION = "4.10.4"
 
 __title__ = "Django Polymorphic"
 __version__ = VERSION  # version synonym for backwards compatibility