Fix/post delete signal gets called twice for models in a foreign-key …

…relation and cascade deletion constraint (#12)

* Extended _has_signal_listeners in BulkTrackerCollector

* Updates deletion logic to allow fast_delete

* Updates testcases

* Updates comments

---------

Co-authored-by: hassaanalansary <hassaanalansary@yahoo.com>

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 All notable changes to this project will be documented in this file.
 
+## 0.2.1 (2024-07-24)
+- A fix where `post_delete_signal()` was called twice for a model in a foreign-key relationship gets deleted with a cascade deletion constraint.
+
 ## 0.2.0 (2024-07-24)
 - `post_delete_signal()` is now being sent if a parent model was deleted and triggered a cascade delete.
 

bulk_tracker/__init__.py

@@ -1 +1 @@
-__version__ = "0.2.0"
+__version__ = "0.2.1"

bulk_tracker/collector.py

@@ -13,6 +13,7 @@
 
 
 class BulkTrackerCollector(Collector):
+
     def delete(self, *, tracking_info_: TrackingInfo | None = None):
         # sort instance collections
         for model, instances in self.data.items():
@@ -29,8 +30,13 @@ def delete(self, *, tracking_info_: TrackingInfo | None = None):
         if len(self.data) == 1 and len(instances) == 1:
             instance = list(instances)[0]
             if self.can_fast_delete(instance):
+                to_be_deleted = None
+                if post_delete_signal.has_listeners(model):
+                    to_be_deleted = deepcopy(instance)
                 with transaction.mark_for_rollback_on_error(self.using):
                     count = sql.DeleteQuery(model).delete_batch([instance.pk], self.using)
+                if to_be_deleted:
+                    send_post_delete_signal([to_be_deleted], model, tracking_info_)
                 setattr(instance, model._meta.pk.attname, None)
                 return count, {model._meta.label: count}
 

bulk_tracker/models.py

@@ -6,11 +6,7 @@
 from bulk_tracker.collector import BulkTrackerCollector
 from bulk_tracker.helper_objects import TrackingInfo
 from bulk_tracker.managers import BulkTrackerManager
-from bulk_tracker.signals import (
-    send_post_create_signal,
-    send_post_delete_signal,
-    send_post_update_signal,
-)
+from bulk_tracker.signals import send_post_create_signal, send_post_update_signal
 
 
 class BulkTrackerModel(models.Model):
@@ -53,6 +49,4 @@ def delete(self, using=None, keep_parents=False, tracking_info_: TrackingInfo |
         except TypeError:
             collector = BulkTrackerCollector(using=using)
         collector.collect([self], keep_parents=keep_parents)
-        ret = collector.delete(tracking_info_=tracking_info_)
-        send_post_delete_signal([self], model=self.__class__, tracking_info_=tracking_info_)
-        return ret
+        return collector.delete(tracking_info_=tracking_info_)