Fix bulk create with history with duplicates

Issue: 1032

AUTHORS.rst

@@ -119,6 +119,7 @@ Authors
 - Tommy Beadle (`tbeadle <https://github.com/tbeadle>`_)
 - Trey Hunner (`treyhunner <https://github.com/treyhunner>`_)
 - Ulysses Vilela
+- Weston Chan
 - `vnagendra <https://github.com/vnagendra>`_
 - `yakimka <https://github.com/yakimka>`_
 - `Paulo Peres <https://github.com/PauloPeres>`_

CHANGES.rst

@@ -6,6 +6,7 @@ Unreleased
 
 - Fixed typos in the docs
 - Removed n+1 query from ``bulk_create_with_history`` utility (gh-975)
+- Removed extra history objects when using ``bulk_create_with_history`` with duplicates (gh-1032)
 - Started using ``exists`` query instead of ``count`` in ``populate_history`` command (gh-982)
 - Added support for Django 4.1 (gh-1021)
 

simple_history/tests/tests/test_utils.py

@@ -2,6 +2,7 @@
 from unittest.mock import Mock, patch
 
 from django.contrib.auth import get_user_model
+from django.core.exceptions import FieldError
 from django.db import IntegrityError, transaction
 from django.test import TestCase, TransactionTestCase, override_settings
 from django.utils import timezone
@@ -124,8 +125,8 @@ def test_bulk_create_history_with_default_date(self):
             all([history.history_date == date for history in Poll.history.all()])
         )
 
-    def test_bulk_create_history_num_queries_is_two(self):
-        with self.assertNumQueries(2):
+    def test_bulk_create_history_num_queries_is_three(self):
+        with self.assertNumQueries(3):
             bulk_create_with_history(self.data, Poll)
 
     def test_bulk_create_history_on_model_without_history_raises_error(self):
@@ -138,7 +139,7 @@ def test_bulk_create_history_on_model_without_history_raises_error(self):
             bulk_create_with_history(self.data, Place)
 
     def test_num_queries_when_batch_size_is_less_than_total(self):
-        with self.assertNumQueries(6):
+        with self.assertNumQueries(7):
             bulk_create_with_history(self.data, Poll, batch_size=2)
 
     def test_bulk_create_history_with_batch_size(self):
@@ -211,7 +212,7 @@ def mock_bulk_create(*args, **kwargs):
         with patch.object(
             Poll._default_manager, "bulk_create", side_effect=mock_bulk_create
         ):
-            with self.assertNumQueries(3):
+            with self.assertNumQueries(4):
                 result = bulk_create_with_history(objects, Poll)
             self.assertEqual(
                 [poll.question for poll in result], [poll.question for poll in objects]
@@ -262,7 +263,7 @@ def test_bulk_create_history_rolls_back_when_last_exists(self):
         self.assertEqual(Poll.history.count(), 1)
 
     def test_bulk_create_fails_with_wrong_model(self):
-        with self.assertRaises(AttributeError):
+        with self.assertRaises(FieldError):
             bulk_create_with_history(self.data, Document)
 
         self.assertEqual(Poll.objects.count(), 0)
@@ -271,14 +272,11 @@ def test_bulk_create_fails_with_wrong_model(self):
     @patch("simple_history.utils.get_history_manager_for_model")
     def test_bulk_create_no_ids_return(self, hist_manager_mock):
         objects = [Place(id=1, name="Place 1")]
-        model = Mock(
-            _default_manager=Mock(
-                bulk_create=Mock(return_value=[Place(name="Place 1")]),
-                filter=Mock(return_value=Mock(order_by=Mock(return_value=objects))),
-            ),
-            _meta=Mock(get_fields=Mock(return_value=[])),
+        Place._default_manager.bulk_create = Mock(
+            side_effect=Place._default_manager.bulk_create,
+            return_value=[Place(name="Place 1")],
         )
-        result = bulk_create_with_history(objects, model)
+        result = bulk_create_with_history(objects, Place)
         self.assertEqual(result, objects)
         hist_manager_mock().bulk_history_create.assert_called_with(
             objects,
@@ -288,6 +286,18 @@ def test_bulk_create_no_ids_return(self, hist_manager_mock):
             default_date=None,
         )
 
+    def test_bulk_create_duplicate_objects_with_no_ids_return(self):
+        Street._default_manager.create(id=1, name="Duplicate Place")
+        obj = Street(name="Duplicate Place")
+        Street._default_manager.bulk_create = Mock(
+            side_effect=Street._default_manager.bulk_create,
+            return_value=[Street(name="Duplicate Place")],
+        )
+        result = bulk_create_with_history([obj], Street)
+        self.assertEqual(result, [Street._default_manager.last()])
+        self.assertEqual(Street._default_manager.count(), 2)
+        self.assertEqual(Street.log.count(), 2)
+
 
 class BulkCreateWithManyToManyField(TestCase):
     def setUp(self):

simple_history/utils.py

@@ -93,58 +93,52 @@ def bulk_create_with_history(
     history_manager = get_history_manager_for_model(model)
     model_manager = model._default_manager
 
-    second_transaction_required = True
     with transaction.atomic(savepoint=False):
+        # Retrieve any duplicate existing objects,
+        # so we can exclude them when finding the created objects
+        cumulative_filter = None
+        obj_when_list = []
+        for i, obj in enumerate(objs):
+            attributes = {
+                k: v
+                for k, v in model_to_dict(obj, exclude=exclude_fields).items()
+                if v is not None
+            }
+            # https://stackoverflow.com/a/49625179/1960509
+            # DEV: If an attribute has `then` as a key
+            #   then they'll also run into issues with `bulk_update`
+            #   due to shared implementation
+            #   https://github.com/django/django/blob/4.0.4/django/db/models/query.py#L624-L638
+            obj_when_list.append(When(**attributes, then=i))
+            q = Q(**attributes)
+            cumulative_filter = (cumulative_filter | q) if cumulative_filter else q
+        existing_objs_ids = list(
+            model_manager.filter(cumulative_filter).values_list("pk", flat=True)
+        )
         objs_with_id = model_manager.bulk_create(
             objs, batch_size=batch_size, ignore_conflicts=ignore_conflicts
         )
         if objs_with_id and objs_with_id[0].pk and not ignore_conflicts:
-            second_transaction_required = False
             history_manager.bulk_history_create(
                 objs_with_id,
                 batch_size=batch_size,
                 default_user=default_user,
                 default_change_reason=default_change_reason,
                 default_date=default_date,
             )
-    if second_transaction_required:
-        with transaction.atomic(savepoint=False):
-            # Generate a common query to avoid n+1 selections
-            #   https://github.com/jazzband/django-simple-history/issues/974
-            cumulative_filter = None
-            obj_when_list = []
-            for i, obj in enumerate(objs_with_id):
-                attributes = dict(
-                    filter(
-                        lambda x: x[1] is not None,
-                        model_to_dict(obj, exclude=exclude_fields).items(),
-                    )
-                )
-                q = Q(**attributes)
-                cumulative_filter = (cumulative_filter | q) if cumulative_filter else q
-                # https://stackoverflow.com/a/49625179/1960509
-                # DEV: If an attribute has `then` as a key
-                #   then they'll also run into issues with `bulk_update`
-                #   due to shared implementation
-                #   https://github.com/django/django/blob/4.0.4/django/db/models/query.py#L624-L638
-                obj_when_list.append(When(**attributes, then=i))
-            obj_list = (
-                list(
-                    model_manager.filter(cumulative_filter).order_by(
-                        Case(*obj_when_list)
-                    )
-                )
-                if objs_with_id
-                else []
+        elif objs_with_id:
+            objs_with_id = list(
+                model_manager.filter(cumulative_filter)
+                .exclude(pk__in=existing_objs_ids)
+                .order_by(Case(*obj_when_list))
             )
             history_manager.bulk_history_create(
-                obj_list,
+                objs_with_id,
                 batch_size=batch_size,
                 default_user=default_user,
                 default_change_reason=default_change_reason,
                 default_date=default_date,
             )
-        objs_with_id = obj_list
     return objs_with_id