Add raw ID m2m admin test

src/polymorphic/tests/admin.py

@@ -21,6 +21,10 @@
     InlineParent,
     NoChildren,
     ModelWithPolyFK,
+    M2MAdminTest,
+    M2MAdminTestChildA,
+    M2MAdminTestChildB,
+    M2MAdminTestChildC,
 )
 
 
@@ -79,3 +83,24 @@ class NoChildrenAdmin(PolymorphicParentModelAdmin):
 @register(ModelWithPolyFK)
 class ModelWithPolyFKAdmin(ModelAdmin):
     fields = ["name", "poly_fk"]
+
+
+@register(M2MAdminTest)
+class M2MAdminTestAdmin(PolymorphicParentModelAdmin):
+    list_filter = (PolymorphicChildModelFilter,)
+    child_models = (M2MAdminTestChildA, M2MAdminTestChildB, M2MAdminTestChildC)
+
+
+@register(M2MAdminTestChildA)
+class M2MAdminTestChildA(PolymorphicChildModelAdmin):
+    raw_id_fields = ("child_bs",)
+
+
+@register(M2MAdminTestChildB)
+class M2MAdminTestChildB(PolymorphicChildModelAdmin):
+    raw_id_fields = ("child_as",)
+
+
+@register(M2MAdminTestChildC)
+class M2MAdminTestChildC(PolymorphicChildModelAdmin):
+    raw_id_fields = ("child_as",)

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

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2026-01-06 23:40
+# Generated by Django 4.2 on 2026-01-07 11:43
 
 from decimal import Decimal
 from django.conf import settings

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

@@ -1,4 +1,4 @@
-# Generated by Django 4.2 on 2026-01-06 23:40
+# Generated by Django 4.2 on 2026-01-07 11:43
 
 from django.conf import settings
 from django.db import migrations, models
@@ -193,6 +193,18 @@ class Migration(migrations.Migration):
                 ('title', models.CharField(max_length=30)),
             ],
         ),
+        migrations.CreateModel(
+            name='M2MAdminTest',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=30)),
+                ('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',
+            },
+        ),
         migrations.CreateModel(
             name='Model2A',
             fields=[
@@ -579,6 +591,29 @@ class Migration(migrations.Migration):
             },
             bases=('tests.inittestmodel',),
         ),
+        migrations.CreateModel(
+            name='M2MAdminTestChildA',
+            fields=[
+                ('m2madmintest_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.m2madmintest')),
+            ],
+            options={
+                'abstract': False,
+                'base_manager_name': 'objects',
+            },
+            bases=('tests.m2madmintest',),
+        ),
+        migrations.CreateModel(
+            name='M2MAdminTestChildB',
+            fields=[
+                ('m2madmintest_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.m2madmintest')),
+                ('child_as', models.ManyToManyField(blank=True, related_name='related_bs', to='tests.m2madmintestchilda')),
+            ],
+            options={
+                'abstract': False,
+                'base_manager_name': 'objects',
+            },
+            bases=('tests.m2madmintest',),
+        ),
         migrations.CreateModel(
             name='Middle',
             fields=[
@@ -1418,6 +1453,17 @@ class Migration(migrations.Migration):
             },
             bases=('tests.disparatekeyschild2',),
         ),
+        migrations.CreateModel(
+            name='M2MAdminTestChildC',
+            fields=[
+                ('m2madmintestchildb_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='tests.m2madmintestchildb')),
+            ],
+            options={
+                'abstract': False,
+                'base_manager_name': 'objects',
+            },
+            bases=('tests.m2madmintestchildb',),
+        ),
         migrations.CreateModel(
             name='Model2C',
             fields=[
@@ -1561,6 +1607,11 @@ class Migration(migrations.Migration):
                 ('user_profiles', models.ManyToManyField(related_name='user_teams', to='tests.userprofile')),
             ],
         ),
+        migrations.AddField(
+            model_name='m2madmintestchilda',
+            name='child_bs',
+            field=models.ManyToManyField(blank=True, related_name='related_as', to='tests.m2madmintestchildb'),
+        ),
         migrations.CreateModel(
             name='InlineModelB',
             fields=[

src/polymorphic/tests/models.py

@@ -888,3 +888,22 @@ class DisparateKeysGrandChild2(DisparateKeysChild2):
 
 class DisparateKeysGrandChild(DisparateKeysChild1):
     text_grand_child = models.CharField(max_length=30)
+
+
+class M2MAdminTest(PolymorphicModel):
+    name = models.CharField(max_length=30)
+
+    def __str__(self):
+        return self.name
+
+
+class M2MAdminTestChildA(M2MAdminTest):
+    child_bs = models.ManyToManyField("M2MAdminTestChildB", related_name="related_as", blank=True)
+
+
+class M2MAdminTestChildB(M2MAdminTest):
+    child_as = models.ManyToManyField("M2MAdminTestChildA", related_name="related_bs", blank=True)
+
+
+class M2MAdminTestChildC(M2MAdminTestChildB):
+    pass

src/polymorphic/tests/test_admin.py

@@ -898,3 +898,147 @@ def test_changelist_filter_persists_after_edit(self):
         ]
         # Only obj_b should be displayed (obj_c has a different content type)
         assert displayed_ids == [obj_b.pk]
+
+
+class M2MAdminTests(_GenericAdminFormTest):
+    def test_m2m_admin_raw_id_fields(self):
+        """
+        Test M2M relationships in polymorphic admin using raw_id_fields.
+
+        This test verifies that:
+        1. M2M relationships can be created between polymorphic child models
+        2. Raw ID field lookups display the correct polymorphic instances
+        3. M2M relationships are properly saved and displayed
+        """
+        from polymorphic.tests.models import (
+            M2MAdminTestChildA,
+            M2MAdminTestChildB,
+            M2MAdminTestChildC,
+        )
+
+        # Create test instances
+        a1 = M2MAdminTestChildA.objects.create(name="A1")
+        b1 = M2MAdminTestChildB.objects.create(name="B1")
+        c1 = M2MAdminTestChildC.objects.create(name="C1")
+
+        # Navigate to A1's change page
+        self.page.goto(self.change_url(M2MAdminTestChildA, a1.pk))
+
+        # Verify the page loaded correctly
+        assert self.page.locator("input[name='name']").input_value() == "A1"
+
+        # Test adding B1 to A1's child_bs field using the raw ID lookup
+        # Click the lookup button (magnifying glass icon) for child_bs
+        with self.page.expect_popup(timeout=10000) as popup_info:
+            self.page.click("a#lookup_id_child_bs")
+
+        popup = popup_info.value
+        popup.wait_for_load_state("networkidle")
+
+        # In the popup, we should see both B1 and C1 (since C1 is a subclass of B)
+        # Verify B1 is present in the list
+        b1_link = popup.locator("table#result_list a:has-text('B1')")
+        expect(b1_link).to_be_visible()
+
+        # Verify C1 is present in the list
+        c1_link = popup.locator("table#result_list a:has-text('C1')")
+        expect(c1_link).to_be_visible()
+
+        # Verify that A1 is not present
+        expect(popup.locator("table#result_list a:has-text('A1')")).to_have_count(0)
+
+        # Click B1 to select it
+        with popup.expect_event("close", timeout=10000):
+            b1_link.click()
+
+        # Wait a moment for the popup to close and value to be set
+        self.page.wait_for_timeout(500)
+
+        # Verify B1's ID was added to the raw ID field
+        child_bs_value = self.page.locator("input[name='child_bs']").input_value()
+        assert str(b1.pk) in child_bs_value
+
+        # Now add C1 as well by clicking the lookup again
+        with self.page.expect_popup(timeout=10000) as popup_info:
+            self.page.click("a#lookup_id_child_bs")
+
+        popup = popup_info.value
+        popup.wait_for_load_state("networkidle")
+
+        # Click C1 to add it
+        c1_link = popup.locator("table#result_list a:has-text('C1')")
+        with popup.expect_event("close", timeout=10000):
+            c1_link.click()
+
+        self.page.wait_for_timeout(500)
+
+        # Verify both B1 and C1 are in the raw ID field (comma-separated)
+        child_bs_value = self.page.locator("input[name='child_bs']").input_value()
+        assert str(b1.pk) in child_bs_value
+        assert str(c1.pk) in child_bs_value
+
+        # Save the changes to A1
+        with self.page.expect_navigation(timeout=10000) as nav_info:
+            self.page.click("input[name='_save']")
+
+        response = nav_info.value
+        assert response.status < 400
+
+        # Verify the relationships were saved
+        a1.refresh_from_db()
+        child_bs_ids = set(a1.child_bs.values_list("pk", flat=True))
+        assert b1.pk in child_bs_ids
+        assert c1.pk in child_bs_ids
+        assert len(child_bs_ids) == 2
+
+        # Now test the reverse relationship: add A1 to B1's child_as
+        self.page.goto(self.change_url(M2MAdminTestChildB, b1.pk))
+
+        # Verify the page loaded correctly
+        assert self.page.locator("input[name='name']").input_value() == "B1"
+
+        # Click the lookup button for child_as
+        with self.page.expect_popup(timeout=10000) as popup_info:
+            self.page.click("a#lookup_id_child_as")
+
+        popup = popup_info.value
+        popup.wait_for_load_state("networkidle")
+
+        # In the popup, we should see A1
+        a1_link = popup.locator("table#result_list a:has-text('A1')")
+        expect(a1_link).to_be_visible()
+
+        # Verify that AB is not present
+        expect(popup.locator("table#result_list a:has-text('B1')")).to_have_count(0)
+        expect(popup.locator("table#result_list a:has-text('C1')")).to_have_count(0)
+
+        # Click A1 to select it
+        with popup.expect_event("close", timeout=10000):
+            a1_link.click()
+
+        self.page.wait_for_timeout(500)
+
+        # Verify A1's ID was added to the raw ID field
+        child_as_value = self.page.locator("input[name='child_as']").input_value()
+        assert str(a1.pk) in child_as_value
+
+        # Save the changes to B1
+        with self.page.expect_navigation(timeout=10000) as nav_info:
+            self.page.click("input[name='_save']")
+
+        response = nav_info.value
+        assert response.status < 400
+
+        # Verify the relationship was saved
+        b1.refresh_from_db()
+        child_as_ids = set(b1.child_as.values_list("pk", flat=True))
+        assert a1.pk in child_as_ids
+        assert len(child_as_ids) == 1
+
+        # Verify the relationships display correctly when we go back to the change page
+        self.page.goto(self.change_url(M2MAdminTestChildA, a1.pk))
+
+        # The raw ID field should show both B1 and C1
+        child_bs_value = self.page.locator("input[name='child_bs']").input_value()
+        assert str(b1.pk) in child_bs_value
+        assert str(c1.pk) in child_bs_value