Closes #19924: Record model features on ObjectType (#19939)

* Convert ObjectType to a concrete child model of ContentType

* Add public flag to ObjectType

* Catch post_migrate signal to update ObjectTypes

* Reference ObjectType records instead of registry for feature support

* Automatically create ObjectTypes

* Introduce has_feature() utility function

* ObjectTypeManager should not inherit from ContentTypeManager

* Misc cleanup

* Don't populate ObjectTypes during migration

* Don't automatically create ObjectTypes when a ContentType is created

* Fix test

* Extend has_feature() to accept a model or OT/CT

* Misc cleanup

* Deprecate get_for_id() on ObjectTypeManager

* Rename contenttypes.py to object_types.py

* Add index to features ArrayField

* Keep FK & M2M fields pointing to ContentType

* Add get_for_models() to ObjectTypeManager

* Add tests for manager methods & utility functions

* Fix migrations for M2M relations to ObjectType

* model_is_public() should return False for non-core & non-plugin models

* Order ObjectType by app_label & model name

* Resolve migrations conflict

netbox/core/tests/test_models.py

@@ -1,7 +1,10 @@
+from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ObjectDoesNotExist
 from django.test import TestCase
 
-from core.models import DataSource
+from core.models import DataSource, ObjectType
 from core.choices import ObjectChangeActionChoices
+from dcim.models import Site, Location, Device
 from netbox.constants import CENSOR_TOKEN, CENSOR_TOKEN_CHANGED
 
 
@@ -120,3 +123,80 @@ class DataSourceChangeLoggingTestCase(TestCase):
         self.assertEqual(objectchange.prechange_data['parameters']['password'], CENSOR_TOKEN)
         self.assertEqual(objectchange.postchange_data['parameters']['username'], 'username2')
         self.assertEqual(objectchange.postchange_data['parameters']['password'], CENSOR_TOKEN)
+
+
+class ObjectTypeTest(TestCase):
+
+    def test_create(self):
+        """
+        Test that an ObjectType created for a given app_label & model name will be automatically assigned to
+        the appropriate ContentType.
+        """
+        kwargs = {
+            'app_label': 'foo',
+            'model': 'bar',
+        }
+        ct = ContentType.objects.create(**kwargs)
+        ot = ObjectType.objects.create(**kwargs)
+        self.assertEqual(ot.contenttype_ptr, ct)
+
+    def test_get_by_natural_key(self):
+        """
+        Test that get_by_natural_key() returns the appropriate ObjectType.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_by_natural_key('dcim', 'site'),
+            ObjectType.objects.get(app_label='dcim', model='site')
+        )
+        with self.assertRaises(ObjectDoesNotExist):
+            ObjectType.objects.get_by_natural_key('foo', 'bar')
+
+    def test_get_for_id(self):
+        """
+        Test that get_by_id() returns the appropriate ObjectType.
+        """
+        ot = ObjectType.objects.get_by_natural_key('dcim', 'site')
+        self.assertEqual(
+            ObjectType.objects.get_for_id(ot.pk),
+            ObjectType.objects.get(pk=ot.pk)
+        )
+        with self.assertRaises(ObjectDoesNotExist):
+            ObjectType.objects.get_for_id(0)
+
+    def test_get_for_model(self):
+        """
+        Test that get_by_model() returns the appropriate ObjectType.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_for_model(Site),
+            ObjectType.objects.get_by_natural_key('dcim', 'site')
+        )
+
+    def test_get_for_models(self):
+        """
+        Test that get_by_models() returns the appropriate ObjectType mapping.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_for_models(Site, Location, Device),
+            {
+                Site: ObjectType.objects.get_by_natural_key('dcim', 'site'),
+                Location: ObjectType.objects.get_by_natural_key('dcim', 'location'),
+                Device: ObjectType.objects.get_by_natural_key('dcim', 'device'),
+            }
+        )
+
+    def test_public(self):
+        """
+        Test that public() returns only ObjectTypes for public models.
+        """
+        public_ots = ObjectType.objects.public()
+        self.assertIn(ObjectType.objects.get_by_natural_key('dcim', 'site'), public_ots)
+        self.assertNotIn(ObjectType.objects.get_by_natural_key('extras', 'taggeditem'), public_ots)
+
+    def test_with_feature(self):
+        """
+        Test that with_feature() returns only ObjectTypes for models which support the specified feature.
+        """
+        bookmarks_ots = ObjectType.objects.with_feature('bookmarks')
+        self.assertIn(ObjectType.objects.get_by_natural_key('dcim', 'site'), bookmarks_ots)
+        self.assertNotIn(ObjectType.objects.get_by_natural_key('dcim', 'cabletermination'), bookmarks_ots)