Fixed #28116 -- Used error code filtering in PostgreSQL test database creation.

Thanks Claude Paroz and Tim Graham for reviews.

1 files changed, 15 insertions, 4 deletions

diff --git a/tests/backends/test_creation.py b/tests/backends/test_creation.py
index 2ecd03ce2d..90ea59086e 100644
--- a/tests/backends/test_creation.py
+++ b/tests/backends/test_creation.py
@@ -12,11 +12,18 @@ from django.db.backends.mysql.creation import \
     DatabaseCreation as MySQLDatabaseCreation
 from django.db.backends.oracle.creation import \
     DatabaseCreation as OracleDatabaseCreation
-from django.db.backends.postgresql.creation import \
-    DatabaseCreation as PostgreSQLDatabaseCreation
 from django.db.utils import DatabaseError
 from django.test import SimpleTestCase, TestCase
 
+try:
+    import psycopg2  # NOQA
+except ImportError:
+    pass
+else:
+    from psycopg2 import errorcodes
+    from django.db.backends.postgresql.creation import \
+        DatabaseCreation as PostgreSQLDatabaseCreation
+
 
 class TestDbSignatureTests(SimpleTestCase):
 
@@ -98,10 +105,14 @@ class PostgreSQLDatabaseCreationTests(SimpleTestCase):
         self.check_sql_table_creation_suffix(settings, '''WITH ENCODING 'UTF8' TEMPLATE "template0"''')
 
     def _execute_raise_database_already_exists(self, cursor, parameters, keepdb=False):
-        raise DatabaseError('database %s already exists' % parameters['dbname'])
+        error = DatabaseError('database %s already exists' % parameters['dbname'])
+        error.pgcode = errorcodes.DUPLICATE_DATABASE
+        raise DatabaseError() from error
 
     def _execute_raise_permission_denied(self, cursor, parameters, keepdb=False):
-        raise DatabaseError('permission denied to create database')
+        error = DatabaseError('permission denied to create database')
+        error.pgcode = errorcodes.INSUFFICIENT_PRIVILEGE
+        raise DatabaseError() from error
 
     def patch_test_db_creation(self, execute_create_test_db):
         return mock.patch.object(BaseDatabaseCreation, '_execute_create_test_db', execute_create_test_db)