test num queries

simple_history/tests/tests/test_utils.py

@@ -37,6 +37,7 @@
     get_m2m_reverse_field_name,
     update_change_reason,
 )
+from .utils import db_supports_returning_autofield_pks
 
 User = get_user_model()
 
@@ -155,6 +156,28 @@ def test_bulk_create_history_with_disabled_setting(self):
         self.assertEqual(Poll.objects.count(), 5)
         self.assertEqual(Poll.history.count(), 0)
 
+    def test_bulk_create_history_without_pks(self):
+        for poll in self.data:
+            poll.pk = None
+
+        # An extra query must be made on some DBs to retrieve the auto-generated PKs
+        with self.assertNumQueries(2 if db_supports_returning_autofield_pks() else 3):
+            bulk_create_with_history(self.data, Poll)
+
+        self.assertEqual(Poll.objects.count(), 5)
+        self.assertEqual(Poll.history.count(), 5)
+
+    def test_bulk_create_history_without_some_pks(self):
+        self.data[1].pk = None
+        self.data[3].pk = None
+
+        # An extra query must be made on some DBs to retrieve the auto-generated PKs
+        with self.assertNumQueries(3 if db_supports_returning_autofield_pks() else 4):
+            bulk_create_with_history(self.data, Poll)
+
+        self.assertEqual(Poll.objects.count(), 5)
+        self.assertEqual(Poll.history.count(), 5)
+
     def test_bulk_create_history_alternative_manager(self):
         bulk_create_with_history(
             self.data,

simple_history/tests/tests/utils.py

@@ -1,8 +1,10 @@
 from enum import Enum
 from typing import Type
+from functools import cache
 
 from django.conf import settings
 from django.db.models import Model
+from django.db import connection
 from django.test import TestCase
 
 request_middleware = "simple_history.middleware.HistoryRequestMiddleware"
@@ -35,6 +37,16 @@ def assertRecordValues(self, record, klass: Type[Model], values_dict: dict):
                 self.assertEqual(getattr(record.history_object, key), value)
 
 
+@cache
+def db_supports_returning_autofield_pks() -> bool:
+    # See https://docs.djangoproject.com/en/stable/ref/models/querysets/#bulk-create
+    return connection.display_name.lower() in {
+        "postgresql",
+        "mariadb",
+        "sqlite",
+    }
+
+
 class TestDbRouter:
     def db_for_read(self, model, **hints):
         if model._meta.app_label == "external":