With some delay, this is a PR for
https://github.com/grpc/grpc/issues/32564 (and previously
https://github.com/grpc/grpc/pull/31791).
I looked into adding a regular `py_test` for this change [as
suggested](https://github.com/grpc/grpc/pull/31791#issuecomment-1423245116)
but I am not aware of any effect that the presence of a .pyi stub file
would have at runtime and where some sort of type-checking in a .py
script would be affected. Stub files are only for use by type checkers &
IDE's. I mean, something like this would work:
```
import helloworld_pb2
py_file = helloworld_pb2.__file__
pyi_file = py_file + 'i’
self.assertTrue(os.path.exists(pyi_file))
```
But that seems really hacky to me. Instead I created a simple rule test
for `py_proto_library` with Bazel Skylib which tests the declared
outputs for an example `py_proto_library` target. Indirectly, this also
tests that the declared output files are actually generated. Please let
me know if this is sufficient.
fa32eb36b3