Merge pull request #716 from bckohan/master

Add a test for extending a normal base model as polymorphic

src/polymorphic/tests/migrations/0001_initial.py

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2025-12-11 17:03
+# Generated by Django 4.2 on 2025-12-11 18:22
 
 from django.conf import settings
 from django.db import migrations, models
@@ -230,6 +230,13 @@ class Migration(migrations.Migration):
                 'base_manager_name': 'objects',
             },
         ),
+        migrations.CreateModel(
+            name='NormalBase',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('nb_field', models.IntegerField()),
+            ],
+        ),
         migrations.CreateModel(
             name='One2OneRelatingModel',
             fields=[
@@ -642,6 +649,14 @@ class Migration(migrations.Migration):
             },
             bases=('tests.proxybase',),
         ),
+        migrations.CreateModel(
+            name='NormalExtension',
+            fields=[
+                ('normalbase_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.normalbase')),
+                ('ne_field', models.CharField(max_length=12)),
+            ],
+            bases=('tests.normalbase',),
+        ),
         migrations.CreateModel(
             name='One2OneRelatingModelDerived',
             fields=[
@@ -1204,6 +1219,19 @@ class Migration(migrations.Migration):
             ],
             bases=('tests.plainb',),
         ),
+        migrations.CreateModel(
+            name='PolyExtension',
+            fields=[
+                ('normalextension_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.normalextension')),
+                ('poly_ext_field', models.IntegerField()),
+                ('polymorphic_ctype', models.ForeignKey(editable=False, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='polymorphic_%(app_label)s.%(class)s_set+', to='contenttypes.contenttype')),
+            ],
+            options={
+                'abstract': False,
+                'base_manager_name': 'objects',
+            },
+            bases=('tests.normalextension', models.Model),
+        ),
         migrations.CreateModel(
             name='ProxyModelA',
             fields=[
@@ -1340,6 +1368,18 @@ class Migration(migrations.Migration):
             },
             bases=('tests.model2c',),
         ),
+        migrations.CreateModel(
+            name='PolyExtChild',
+            fields=[
+                ('polyextension_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.polyextension')),
+                ('poly_child_field', models.CharField(max_length=12)),
+            ],
+            options={
+                'abstract': False,
+                'base_manager_name': 'objects',
+            },
+            bases=('tests.polyextension',),
+        ),
         migrations.CreateModel(
             name='UUIDArtProjectB',
             fields=[

src/polymorphic/tests/models.py

@@ -714,3 +714,19 @@ class FKTest(models.Model):
 
 class NoChildren(PolymorphicModel):
     field1 = models.CharField(max_length=12)
+
+
+class NormalBase(models.Model):
+    nb_field = models.IntegerField()
+
+
+class NormalExtension(NormalBase):
+    ne_field = models.CharField(max_length=12)
+
+
+class PolyExtension(PolymorphicModel, NormalExtension):
+    poly_ext_field = models.IntegerField()
+
+
+class PolyExtChild(PolyExtension):
+    poly_child_field = models.CharField(max_length=12)

src/polymorphic/tests/test_orm.py

@@ -1707,3 +1707,31 @@ class PolymorphicTests(TransactionTestCase):
 
         assert fk_test.fk == child
         assert isinstance(fk_test.fk, FKTestChild)
+
+    def test_polymorphic_extension(self):
+        from polymorphic.tests.models import (
+            NormalBase,
+            NormalExtension,
+            PolyExtension,
+            PolyExtChild,
+        )
+
+        nb = NormalBase.objects.create(nb_field=5)
+        ne = NormalExtension.objects.create(nb_field=6, ne_field="normal ext")
+        poly_ext = PolyExtension.objects.create(nb_field=6, ne_field="poly ext", poly_ext_field=7)
+        child_ext = PolyExtChild.objects.create(
+            nb_field=7, ne_field="child ext", poly_ext_field=8, poly_child_field="poly child"
+        )
+        assert set(NormalBase.objects.all()) == {
+            nb,
+            NormalBase.objects.get(pk=ne.pk),
+            NormalBase.objects.get(pk=poly_ext.pk),
+            NormalBase.objects.get(pk=child_ext.pk),
+        }
+        assert set(NormalExtension.objects.all()) == {
+            NormalExtension.objects.get(pk=ne.pk),
+            NormalExtension.objects.get(pk=poly_ext.pk),
+            NormalExtension.objects.get(pk=child_ext.pk),
+        }
+        assert set(PolyExtension.objects.all()) == {poly_ext, child_ext}
+        assert set(PolyExtChild.objects.all()) == {child_ext}