[minulo]

Summary

Implemented test enhancement per this post.

What this PR does

Runs the unit tests of every charm in the monorepo with pytest's filterwarnings = ["error"], so a deprecation, a leaked file handle or a misused library fails the test instead of scrolling past in the log. canonical/indico-operator#776 is the same change on indico.

Configuration

• haproxy-operator, haproxy-route-policy-operator, haproxy-spoe-auth-operator and haproxy-ddos-protection-configurator: pyproject.toml gains filterwarnings with "error" first. Each tox.toml integration env passes --override-ini=filterwarnings=, so warnings from the deployment tooling cannot break those runs.
• haproxy-route-policy-operator ignores one third-party warning by message: JujuVersion.from_environ() is deprecated, raised by the vendored data_platform_libs lib, which still makes that call at its newest patch.
• The three legacy Harness modules in haproxy-operator/tests/unit/legacy ignore ops' Harness is deprecated warning through a module-level pytestmark. Harness used anywhere else still fails.
• haproxy-route-policy runs Django's test runner rather than pytest, so its unit and unit_auth envs run under python -W error instead.

Fixes for warnings that were ours

• haproxy-operator/tests/unit/conftest.py: the TLS fixtures called the deprecated generate_private_key(), generate_csr(), generate_ca() and generate_certificate() helpers. They now use PrivateKey.generate(), CertificateRequestAttributes.generate_csr(), Certificate.generate_self_signed_ca() and Certificate.generate().
• haproxy-operator/tests/unit/legacy/test_haproxy_route_lib.py: the mock_requirer_charm fixture never cleaned up its Harness. Its temporary directory was reclaimed by the garbage collector with a ResourceWarning, which then failed whichever test happened to be running. The fixture now yields the harness and calls cleanup().
• haproxy-route-policy test settings: WhiteNoise warned No directory at: .../static/ because tests do not run collectstatic. Both test settings now set WHITENOISE_AUTOREFRESH = True.

Why we need it

Deprecation and resource warnings are easy to miss in CI logs. Promoting them to errors surfaces them when they are cheap to fix rather than when the API is removed. Turning it on here already found a real resource leak in the legacy test fixtures.

Test plan

Project	Before	After
haproxy-operator	351 passed, 163 warnings	351 passed, no warnings, run three times
haproxy-route-policy-operator	31 passed, 5 warnings	31 passed, no warnings
haproxy-spoe-auth-operator	1 passed	1 passed
haproxy-ddos-protection-configurator	6 passed	6 passed
haproxy-route-policy	57 tests OK, 7 auth tests OK	the same, under -W error

• The full default tox run passes in all five projects: lint, unit, static and coverage-report.
• Verified the filter bites in each pytest project: a throwaway test that emits a DeprecationWarning fails, and one that leaks a file handle fails with ResourceWarning. The probe file was not committed.
• Integration tests were not run locally; they are deliberately excluded from the filter and CI exercises them.

Review focus

• The CA fixture now signs with the key it returns. Before, generate_ca() was given a throwaway key while the fixture returned a different one, so the issued certificate's signature did not match the CA's key. Tests pass either way, but the new pairing is the consistent one.
• Pre-existing and not changed here: haproxy-route-policy/tox.toml lists unit-auth in envlist but defines the env as unit_auth, so the auth tests do not run by default or in CI. They pass when run directly with tox -e unit_auth.
• The third-party ignore matches on message only, like indico-operator#776. Pinning it to the library's module, ...:DeprecationWarning:charms.data_platform_libs, would keep the same deprecated call in this charm's own code failing. That form also passes the suite.
• No breaking changes, no new dependencies, no workflow changes. Labelled no-release-note since this changes only tests and test configuration.

Checklist

• I followed the contributing guide
• I added or updated the documentation (if applicable) (n/a)
• I updated docs/changelog.md with user-relevant changes (n/a: tests only)
• I added a change artifact for user-relevant changes in docs/release-notes/artifacts. If no change artifact is necessary, I tagged the PR with the label no-release-note.
• I used AI to assist with preparing this PR
• I added or updated tests as needed (unit and integration)

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This PR was assisted by an LLM.

[Thanhphan1147]

@copilot shorten this comment to just "promote warnings to test failures". Apply it every other places

[Copilot]

Updated all four pytest configuration comments to “promote warnings to test failures” in commit d07fabd.

[Thanhphan1147]

@copilot shorten this to "Don't promote warnings for integration tests"

[Copilot]

Updated the integration warning comments in all four tox.toml files in commit 2a6d06c.

[Thanhphan1147]

LGTM, thanks! I asked copilot to shorten some of the comments to be more concise.