testing/mock_spanner: failure with TypeError: unsupported operand type(s) for |: 'MessageMeta' and 'MessageMeta'

[odeke-em]

After PR #1271 we get this error

tests/mockserver_tests/mock_server_test_base.py:19: in <module>
    from google.cloud.spanner_v1.testing.mock_spanner import (
google/cloud/spanner_v1/testing/mock_spanner.py:84: in <module>
    class SpannerServicer(spanner_grpc.SpannerServicer):
google/cloud/spanner_v1/testing/mock_spanner.py:190: in SpannerServicer
    self, request: ExecuteSqlRequest | ExecuteBatchDmlRequest
E   TypeError: unsupported operand type(s) for |: 'MessageMeta' and 'MessageMeta'

Perhaps the code was tested only for Python 3.10 and not Python 3.8?

Kindly cc-ing @olavloite

[olavloite]

Yes, those tests are only run with Python 3.12. See https://github.com/googleapis/python-spanner/blob/main/.github/workflows/mock_server_tests.yaml and

python-spanner/noxfile.py

Line 238 in 6352dd2

@nox.session(python=DEFAULT_MOCK_SERVER_TESTS_PYTHON_VERSION)

We could consider adding a runner for Python 3.10, but not for Python 3.8, as it is EOL.

[odeke-em]

@olavloite sadly we still need to have even Python 3.7 support though it has been past EOL since forever. It is the reason why OpenTelemetry needs import guards per #1173 as per Google Cloud Client library expectations.