Refs #33308 -- Added psycopg_any.IsolationLevel.

1 files changed, 19 insertions, 3 deletions

diff --git a/tests/backends/postgresql/tests.py b/tests/backends/postgresql/tests.py
index d375bd2b8c..41d445e6c7 100644
--- a/tests/backends/postgresql/tests.py
+++ b/tests/backends/postgresql/tests.py
@@ -223,7 +223,7 @@ class Tests(TestCase):
         The transaction level can be configured with
         DATABASES ['OPTIONS']['isolation_level'].
         """
-        from psycopg2.extensions import ISOLATION_LEVEL_SERIALIZABLE as serializable
+        from django.db.backends.postgresql.psycopg_any import IsolationLevel
 
         # Since this is a django.test.TestCase, a transaction is in progress
         # and the isolation level isn't reported as 0. This test assumes that
@@ -232,15 +232,31 @@ class Tests(TestCase):
         self.assertIsNone(connection.connection.isolation_level)
 
         new_connection = connection.copy()
-        new_connection.settings_dict["OPTIONS"]["isolation_level"] = serializable
+        new_connection.settings_dict["OPTIONS"][
+            "isolation_level"
+        ] = IsolationLevel.SERIALIZABLE
         try:
             # Start a transaction so the isolation level isn't reported as 0.
             new_connection.set_autocommit(False)
             # Check the level on the psycopg2 connection, not the Django wrapper.
-            self.assertEqual(new_connection.connection.isolation_level, serializable)
+            self.assertEqual(
+                new_connection.connection.isolation_level,
+                IsolationLevel.SERIALIZABLE,
+            )
         finally:
             new_connection.close()
 
+    def test_connect_invalid_isolation_level(self):
+        self.assertIsNone(connection.connection.isolation_level)
+        new_connection = connection.copy()
+        new_connection.settings_dict["OPTIONS"]["isolation_level"] = -1
+        msg = (
+            "Invalid transaction isolation level -1 specified. Use one of the "
+            "IsolationLevel values."
+        )
+        with self.assertRaisesMessage(ImproperlyConfigured, msg):
+            new_connection.ensure_connection()
+
     def test_connect_no_is_usable_checks(self):
         new_connection = connection.copy()
         try: