Fixed #28386 -- Made operations within non-atomic migrations honor the operation's atomic flag when migrating backwards.

3 files changed, 11 insertions, 1 deletions

diff --git a/tests/migrations/test_executor.py b/tests/migrations/test_executor.py
index d6cc802149..fdbc724faf 100644
--- a/tests/migrations/test_executor.py
+++ b/tests/migrations/test_executor.py
@@ -126,6 +126,14 @@ class ExecutorTests(MigrationTestBase):
         migrations_apps = executor.loader.project_state(("migrations", "0001_initial")).apps
         Editor = migrations_apps.get_model("migrations", "Editor")
         self.assertFalse(Editor.objects.exists())
+        # Record previous migration as successful.
+        executor.migrate([("migrations", "0001_initial")], fake=True)
+        # Rebuild the graph to reflect the new DB state.
+        executor.loader.build_graph()
+        # Migrating backwards is also atomic.
+        with self.assertRaisesMessage(RuntimeError, "Abort migration"):
+            executor.migrate([("migrations", None)])
+        self.assertFalse(Editor.objects.exists())
 
     @override_settings(MIGRATION_MODULES={
         "migrations": "migrations.test_migrations",
diff --git a/tests/migrations/test_migrations_atomic_operation/0001_initial.py b/tests/migrations/test_migrations_atomic_operation/0001_initial.py
index 415186423f..47ae3df5e9 100644
--- a/tests/migrations/test_migrations_atomic_operation/0001_initial.py
+++ b/tests/migrations/test_migrations_atomic_operation/0001_initial.py
@@ -18,5 +18,5 @@ class Migration(migrations.Migration):
                 ("name", models.CharField(primary_key=True, max_length=255)),
             ],
         ),
-        migrations.RunPython(raise_error, atomic=True),
+        migrations.RunPython(raise_error, reverse_code=raise_error, atomic=True),
     ]
diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index 86dbb84411..13b511f3aa 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -2055,9 +2055,11 @@ class OperationTests(OperationTestBase):
             with self.assertRaises(ValueError):
                 with connection.schema_editor() as editor:
                     atomic_migration.unapply(project_state, editor)
+            self.assertEqual(project_state.apps.get_model("test_runpythonatomic", "Pony").objects.count(), 0)
             with self.assertRaises(ValueError):
                 with connection.schema_editor() as editor:
                     non_atomic_migration.unapply(project_state, editor)
+            self.assertEqual(project_state.apps.get_model("test_runpythonatomic", "Pony").objects.count(), 1)
         # Verify deconstruction.
         definition = non_atomic_migration.operations[0].deconstruct()
         self.assertEqual(definition[0], "RunPython")