[quality] test: unit coverage for .github/scripts/render_card.py — scripts/test_render_card.py

[kubestellar-hive]

Test Improvement

Claims exactly one file cluster: .github/scripts/render_card.py (test-only; the script itself is unchanged). New test file: scripts/test_render_card.py. Justfile gains one recipe, test-render-card, called from the existing validate recipe.

render_card.py is 542 lines, runs on every publish.yml release to produce the release-card PNG and the release-notes markdown, and had zero test coverage.

Functions covered (31 unittest cases)

Function	Cases
render_chip	changed/unchanged markup, changed without prev, HTML escaping of name/version/prev, missing-key failure
render_diff_bar	has_prev gating, updated/added/removed ordering, zero-count omission, all-zero fallback text
build_html	tag/sha7/long-date substitution, chip + diff-bar embedding, first-release path, no external resource loads, invalid date raises
build_release_notes	all three diff summary lines, notable-versions table (changed and unchanged rows), per-category <details> sections, full-SHA image refs, cosign certificate-identity regexp, no-4-space-indent markdown invariant
main	argparse contract + --output/--release-notes defaults, notes written, temp HTML cleaned up on success and on screenshot failure, notes not written when screenshot fails

The screenshot() Playwright boundary is stubbed, so the suite runs offline with no browser download. Runtime is ~0.01s.

$ just test-render-card
Ran 31 tests in 0.012s
OK

Disjointness

• dakota#1438 covers files/scripts/bst-progress.py → scripts/test_bst_progress.py
• dakota#1430 covers .github/scripts/sbom_diff.py → scripts/test_sbom_diff.py
• dakota#1420 covers scripts/gen-filemap.py → scripts/test_gen_filemap.py
• dakota#1449 / dakota#1437 / dakota#1386 touch no scripts/test_*.py and no .github/scripts/ file

No open PR touches render_card.py or scripts/test_render_card.py. The only shared file is Justfile, where each PR appends its own distinct recipe.

Related Issue

Refs #1440

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Filed by quality agent (hold-gated mode). Human review required.

— hive: agent=quality backend=copilot model=claude-opus-5

[github-actions]

Thanks for the PR! A maintainer will review it.

While you wait, make sure these pass locally:

just validate        # element graph check
just build default   # build the image
just boot-test       # confirm the desktop boots (exits 0 = pass)
just lint            # bootc container lint

If this PR fixes a bug, add verify steps to the linked issue so users can confirm the fix on their hardware after the next nightly ships:

```verify
ujust <something>   # what users should run to confirm the fix
```