Test the behavior of .descendants() queries

CHANGELOG.rst

@@ -4,7 +4,9 @@ Change log
 Next version
 ~~~~~~~~~~~~
 
-- Added Django 5.1b1 to the testsuite.
+- Added Django 5.1 to the testsuite.
+- Added tests showing that ``.descendants().update(...)`` doesn't work, but
+  ``.filter(pk__in=....descendants()).update(...)`` does.
 
 
 0.19 (2024-04-25)

tests/testapp/test_queries.py

@@ -5,6 +5,7 @@
 from django.db import connections, models
 from django.db.models import Count, Q, Sum
 from django.db.models.expressions import RawSQL
+from django.db.utils import OperationalError
 from django.test import TestCase, override_settings
 
 from testapp.models import (
@@ -159,6 +160,54 @@ def test_update_aggregate(self):
             # known yet.
         )
 
+    def test_update_descendants(self):
+        """UpdateQuery does not work with tree queries"""
+        tree = self.create_tree()
+        with self.assertRaises(OperationalError) as cm:
+            tree.root.descendants().update(name="test")
+        self.assertIn("__tree.tree_path", str(cm.exception))
+
+    def test_update_descendants_with_filter(self):
+        """Updating works when using a filter"""
+        tree = self.create_tree()
+        Model.objects.filter(pk__in=tree.child2.descendants()).update(name="test")
+        self.assertEqual(
+            [node.name for node in Model.objects.with_tree_fields()],
+            [
+                "root",
+                "1",
+                "1-1",
+                "2",
+                "test",
+                "test",
+            ],
+        )
+
+    def test_delete_descendants(self):
+        """DeleteQuery works with tree queries"""
+        tree = self.create_tree()
+        tree.child2.descendants(include_self=True).delete()
+
+        self.assertEqual(
+            list(Model.objects.with_tree_fields()),
+            [
+                tree.root,
+                tree.child1,
+                tree.child1_1,
+                # tree.child2,
+                # tree.child2_1,
+                # tree.child2_2,
+            ],
+        )
+
+    def test_aggregate_descendants(self):
+        """AggregateQuery works with tree queries"""
+        tree = self.create_tree()
+        self.assertEqual(
+            tree.root.descendants(include_self=True).aggregate(Sum("pk"))["pk__sum"],
+            sum(node.pk for node in Model.objects.all()),
+        )
+
     def test_values(self):
         self.create_tree()
         self.assertEqual(

tox.ini

@@ -10,7 +10,7 @@ deps =
     dj41: Django>=4.1,<4.2
     dj42: Django>=4.2,<5.0
     dj50: Django>=5.0,<5.1
-    dj51: Django>=5.1b1,<5.2
+    dj51: Django>=5.1,<5.2
     djmain: https://github.com/django/django/archive/main.tar.gz
     postgresql: psycopg2-binary
     mysql: mysqlclient