update the child ordering to be incremental

Author: ozer550

morango/sync/operations.py

@@ -698,7 +698,7 @@ def _update_legacy_self_ref_order_for_model(queryset):
     parent_order = parent.values("_self_ref_order")[:1]
     pending = queryset.exclude(_self_ref_fk="").filter(_self_ref_order=None)
 
-    while pending.filter(Exists(parent)).update(_self_ref_order=Subquery(parent_order)):
+    while pending.filter(Exists(parent)).update(_self_ref_order=Subquery(parent_order) + 1):
         pass
 
 

morango/sync/stream/serialize.py

@@ -219,15 +219,16 @@ def _compute_self_ref_order(self_ref_fk_value):
         Compute ``_self_ref_order`` for a self-referential store record.
 
         Returns ``0`` when the record has no parent (root), otherwise queries
-        the parent ``Store`` row and returns its ``_self_ref_order`` value.
+        the parent ``Store`` row and returns the next order value.
         """
         if not self_ref_fk_value:
             return 0
-        return (
+        parent_order = (
             Store.objects.filter(id=self_ref_fk_value)
             .values_list("_self_ref_order", flat=True)
             .first()
         )
+        return parent_order + 1 if parent_order is not None else None
 
 
 class ModelPartitionBuffer(Buffer[List[SerializeTask]]):

tests/testapp/tests/sync/stream/test_serialize.py

@@ -293,7 +293,7 @@ def test_handle_store_create__self_ref_with_parent(self, _mock_srf):
         self.update._handle_store_create(task)
 
         self.assertEqual(task.store._self_ref_fk, parent_store.id)
-        self.assertEqual(task.store._self_ref_order, 3)
+        self.assertEqual(task.store._self_ref_order, 4)
 
     @mock.patch("morango.sync.stream.serialize.self_referential_fk", return_value="parent_id")
     def test_handle_store_create__self_ref_parent_not_in_store(self, _mock_srf):
@@ -325,7 +325,7 @@ def test_handle_store_update__self_ref_fk_changed(self, _mock_srf):
         self.update._handle_store_update(task)
 
         self.assertEqual(task.store._self_ref_fk, new_parent_store.id)
-        self.assertEqual(task.store._self_ref_order, 7)
+        self.assertEqual(task.store._self_ref_order, 8)
 
 
 class ModelPartitionBufferTestCase(SimpleTestCase):

tests/testapp/tests/sync/test_operations.py

@@ -1023,7 +1023,7 @@ def test_dequeue_into_store__self_ref_order_fallback_for_missing_capability(self
         )
 
         self.assertEqual(Store.objects.get(id=self.data["model3"])._self_ref_order, 0)
-        self.assertEqual(Store.objects.get(id=self.data["model4"])._self_ref_order, 0)
+        self.assertEqual(Store.objects.get(id=self.data["model4"])._self_ref_order, 1)
 
     def test_update_legacy_self_ref_order_nulls_non_self_ref_models(self):
         store = self._make_transferred_store(
@@ -1053,8 +1053,8 @@ def test_update_legacy_self_ref_order_handles_deeper_self_ref_chains(self):
         child.refresh_from_db()
         grandchild.refresh_from_db()
         self.assertEqual(root._self_ref_order, 0)
-        self.assertEqual(child._self_ref_order, 0)
-        self.assertEqual(grandchild._self_ref_order, 0)
+        self.assertEqual(child._self_ref_order, 1)
+        self.assertEqual(grandchild._self_ref_order, 2)
 
     def test_local_dequeue_operation(self):
         self.transfer_session.records_transferred = 1