adding check for nullity in related models delete (#243)

* adding check for nullity in related models delete

* adding check for nullity in queryset delete

safedelete/models.py

@@ -234,8 +234,10 @@ def soft_delete_cascade_policy_action(self, **kwargs) -> Tuple[int, Dict[str, in
         deleted_counter: Counter = Counter()
         for related in related_objects(self):
             if is_safedelete_cls(related.__class__) and not getattr(related, FIELD_NAME):
-                _, delete_response = related.delete(force_policy=SOFT_DELETE, is_cascade=True, **kwargs)
-                deleted_counter.update(delete_response)
+                res = related.delete(force_policy=SOFT_DELETE, is_cascade=True, **kwargs)
+                if res is not None:
+                    _, delete_response = res
+                    deleted_counter.update(delete_response)
 
         # soft-delete the object
         _, delete_response = self._delete(force_policy=SOFT_DELETE, **kwargs)

safedelete/queryset.py

@@ -61,8 +61,10 @@ def delete(self, force_policy: Optional[int] = None) -> Tuple[int, Dict[str, int
             deleted_counter: Counter = Counter()
             # TODO: Replace this by bulk update if we can
             for obj in self.all():
-                _, delete_response = obj.delete(force_policy=force_policy)
-                deleted_counter.update(delete_response)
+                res = obj.delete(force_policy=force_policy)
+                if res is not None:
+                    _, delete_response = res
+                    deleted_counter.update(delete_response)                
             self._result_cache = None
             return sum(deleted_counter.values()), dict(deleted_counter)
     delete.alters_data = True  # type: ignore