google-cloud-spanner post-migration tasks

[parthea]

googleapis/python-spanner was moved to https://github.com/googleapis/google-cloud-python/tree/main/packages/google-cloud-spanner in PR #16488

There is an outstanding step to complete the librarian integration. We need to remove generate_blocked from the .librarian/config.yaml file once that's done.

[jskeet]

I assume this is the right place to note that legacylibrarian currently can't generate this (and neither can new librarian), because the replacements in spanner-integration.yaml can't be performed.

I believe this is due to a change in formatter. The replacement file is looking for:

from google.cloud.spanner_v1.types import transaction

... but the actual code has:

from google.cloud.spanner_v1.types import (
    commit_response,
    result_set,
    spanner,
    transaction,
)

That said, the replacement may not be needed at all, as it already seems to have the import which is added (at least in one of the six cases). Removing that first block from spanner-integration.yaml doesn't entirely fix this, but it moves the problem on. (Unfortunately the diagnostics from the post-processor aren't terribly clear.)

[jskeet]

The second issue is that the replacement for self._interceptor = _LoggingClientInterceptor() isn't idempotent. This can be fixed - somewhat hackily - by removing the blank line in the "after" part.

There's then a third issue for the final replacement, where it now triggers 15 times instead of 9. I don't know whether just changing the expected count is a correct fix or not. (All of these would need to be checked carefully.)

[jskeet]

(With these changes in place, ruff then fails, so there's something else going on, for sure...)

[jskeet]

After removing spanner-integration.yaml entirely, new librarian generation "succeeds" but there are a lot of diffs.

[parthea]

.librarian/generator-input/client-post-processing/spanner-integration.yaml from PR #16548 should resolve the issue. You will also need the changes in .librarian/state.yaml from #16548