PYTHON-2048 Add test case for better error behavior (#1606)

Author: ShaneHarvey

test/mockupdb/test_standalone_shard.py

@@ -0,0 +1,57 @@
+# Copyright 2024-present MongoDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Test errors that come from a standalone shard."""
+from __future__ import annotations
+
+import unittest
+
+from mockupdb import MockupDB, going
+
+from pymongo import MongoClient
+from pymongo.errors import OperationFailure
+
+
+class TestStandaloneShard(unittest.TestCase):
+    # See PYTHON-2048 and SERVER-44591.
+    def test_bulk_txn_error_message(self):
+        server = MockupDB(auto_ismaster={"maxWireVersion": 8})
+        server.run()
+        self.addCleanup(server.stop)
+        client = MongoClient(server.uri)
+        self.addCleanup(client.close)
+
+        with self.assertRaisesRegex(
+            OperationFailure, "This MongoDB deployment does not support retryable writes"
+        ):
+            with going(client.db.collection.insert_many, [{}, {}]):
+                request = server.receives()
+                request.reply(
+                    {
+                        "n": 0,
+                        "ok": 1.0,
+                        "writeErrors": [
+                            {
+                                "code": 20,
+                                "codeName": "IllegalOperation",
+                                "errmsg": "Transaction numbers are only allowed on a replica set member or mongos",
+                                "index": 0,
+                            }
+                        ],
+                    }
+                )
+
+
+if __name__ == "__main__":
+    unittest.main()