Add automated checks to golden files using lower-bound-checker from google-cloud-testutils

[parthea]

There is a tool to check and update the constraints files which as added in googleapis/python-test-utils#8. See the instructions in googleapis/python-test-utils#8 (comment) for information on running the tool. We could run this check on the golden files to ensure that the versions in testing/constraints-3.*.txt match the minimum version of dependencies in setup.py.

As an example.

(py39) partheniou@partheniou-vm-3:~/git/python-test-utils$ lower-bound-checker update --package-name google-auth-oauthlib  --constraints-file /usr/local/google/home/partheniou/git/google-auth-library-python-oauthlib/testing/constraints-3.7.txt
(py39) partheniou@partheniou-vm-3:~/git/python-test-utils$ lower-bound-checker check --package-name google-auth-oauthlib  --constraints-file /usr/local/google/home/partheniou/git/google-auth-library-python-oauthlib/testing/constraints-3.7.txt
All good!

See googleapis/synthtool#1901 for context.

The check already exists in golden files:

gapic-generator-python/tests/integration/goldens/redis/noxfile.py

Lines 118 to 130 in 4b77019

	def check_lower_bounds(session):
	"""Check lower bounds in setup.py are reflected in constraints file"""
	session.install('google-cloud-testutils')
	session.install('.')
	session.run(
	'lower-bound-checker',
	'check',
	'--package-name',
	PACKAGE_NAME,
	'--constraints-file',
	str(LOWER_BOUND_CONSTRAINTS_FILE),
	)

We just need to run the nox session here:

gapic-generator-python/.github/workflows/tests.yaml

Lines 322 to 328 in 4b77019

	- name: Run blacken and lint on the generated output.
	run: |
	nox -f tests/integration/goldens/asset/noxfile.py -s mypy-3.12 blacken lint
	nox -f tests/integration/goldens/credentials/noxfile.py -s mypy-3.12 blacken lint
	nox -f tests/integration/goldens/eventarc/noxfile.py -s mypy-3.12 blacken lint
	nox -f tests/integration/goldens/logging/noxfile.py -s mypy-3.12 blacken lint
	nox -f tests/integration/goldens/redis/noxfile.py -s mypy-3.12 blacken lint