Fixed #29280 -- Made the transactions behavior configurable on SQLite.

tests/backends/sqlite/tests.py

@@ -3,9 +3,11 @@ import re
 import tempfile
 import threading
 import unittest
+from contextlib import contextmanager
 from pathlib import Path
 from unittest import mock
 
+from django.core.exceptions import ImproperlyConfigured
 from django.db import (
     DEFAULT_DB_ALIAS,
     NotSupportedError,
@@ -15,8 +17,8 @@ from django.db import (
 )
 from django.db.models import Aggregate, Avg, StdDev, Sum, Variance
 from django.db.utils import ConnectionHandler
-from django.test import TestCase, TransactionTestCase, override_settings
-from django.test.utils import isolate_apps
+from django.test import SimpleTestCase, TestCase, TransactionTestCase, override_settings
+from django.test.utils import CaptureQueriesContext, isolate_apps
 
 from ..models import Item, Object, Square
 
@@ -245,3 +247,55 @@ class ThreadSharing(TransactionTestCase):
             for conn in thread_connections:
                 if conn is not main_connection:
                     conn.close()
+
+
+@unittest.skipUnless(connection.vendor == "sqlite", "SQLite tests")
+class TestTransactionMode(SimpleTestCase):
+    databases = {"default"}
+
+    def test_default_transaction_mode(self):
+        with CaptureQueriesContext(connection) as captured_queries:
+            with transaction.atomic():
+                pass
+
+        begin_query, commit_query = captured_queries
+        self.assertEqual(begin_query["sql"], "BEGIN")
+        self.assertEqual(commit_query["sql"], "COMMIT")
+
+    def test_invalid_transaction_mode(self):
+        msg = (
+            "settings.DATABASES['default']['OPTIONS']['transaction_mode'] is "
+            "improperly configured to 'invalid'. Use one of 'DEFERRED', 'EXCLUSIVE', "
+            "'IMMEDIATE', or None."
+        )
+        with self.change_transaction_mode("invalid") as new_connection:
+            with self.assertRaisesMessage(ImproperlyConfigured, msg):
+                new_connection.ensure_connection()
+
+    def test_valid_transaction_modes(self):
+        valid_transaction_modes = ("deferred", "immediate", "exclusive")
+        for transaction_mode in valid_transaction_modes:
+            with (
+                self.subTest(transaction_mode=transaction_mode),
+                self.change_transaction_mode(transaction_mode) as new_connection,
+                CaptureQueriesContext(new_connection) as captured_queries,
+            ):
+                new_connection.set_autocommit(
+                    False, force_begin_transaction_with_broken_autocommit=True
+                )
+                new_connection.commit()
+                expected_transaction_mode = transaction_mode.upper()
+                begin_sql = captured_queries[0]["sql"]
+                self.assertEqual(begin_sql, f"BEGIN {expected_transaction_mode}")
+
+    @contextmanager
+    def change_transaction_mode(self, transaction_mode):
+        new_connection = connection.copy()
+        new_connection.settings_dict["OPTIONS"] = {
+            **new_connection.settings_dict["OPTIONS"],
+            "transaction_mode": transaction_mode,
+        }
+        try:
+            yield new_connection
+        finally:
+            new_connection.close()