update with one more test

Author: RulaKhaled

graphql_api/helpers/tests/test_connection.py

@@ -152,3 +152,6 @@ def test_invalid_cursors(self):
 
         with self.assertRaises(ValidationError):
             queryset_to_connection_sync(data, last=3, before="invalid")
+
+        with self.assertRaises(ValidationError):
+            queryset_to_connection_sync(data, first=3, after="invalid")