ci: skip Build & Test e2e for docs/workflow-only PRs

[ricogu]

fix #51

Summary

Stop running the full ~5-minute Build & Test e2e suite on PRs that only change documentation, license metadata, or unrelated workflow files (CodeQL, Dependabot, Renovate, Codeowners). The repository ruleset still requires the all-tests-passed commit status to merge, so a paired skip workflow reports it directly for the ignored paths.

PR #99 is a concrete example of where this would have helped: 4 commits to .github/workflows/codeql.yml triggered 4 full e2e runs, the cancel-in-progress concurrency caused a ~5-minute pending stretch on the latest commit, and none of those runs could possibly have caught a behavior regression — the action runtime wasn't touched.

Why a skip workflow at all

GitHub's required status check rule (required_status_checks → context: all-tests-passed) treats a workflow that doesn't run as not satisfied rather than skipped/passed. Without a paired skip workflow, adding paths-ignore to build-and-test.yml would leave docs-only PRs permanently BLOCKED. The pattern below is GitHub's documented solution for required checks with path filters.

Changes

Modified

• .github/workflows/build-and-test.yml — added paths-ignore: listing files that cannot affect the action runtime.

Added

• .github/workflows/build-and-test-skip.yml — runs on the inverse path set (paths: matches what build-and-test.yml's paths-ignore: excludes) and reports all-tests-passed = success via the same myrotvorets/set-commit-status-action@master call the real workflow uses. Both workflows share name: Build & Test so the status context is identical.

Path list

Files that cannot break the action runtime (skip e2e):

**/*.md
LICENSE
LICENSES/**
REUSE.toml
renovate.json
.gitignore
.github/workflows/codeql.yml
.github/codeql/**
.github/dependabot.yml
.github/CODEOWNERS

Notably not in the list (they still run e2e):

• .github/workflows/build-and-test.yml — changes to the test workflow itself must be exercised end-to-end.
• .github/workflows/release.yml — release logic uses the same composite actions.
• .github/actions/** — the action source itself.
• action.yml — composite action entry point.
• test-resources/** — e2e test fixtures.
• package.json, tsconfig.json, jest.config.* — change the build/test toolchain.

Behavior matrix

PR changes	build-and-test.yml (real)	build-and-test-skip.yml (paired)	Final all-tests-passed status
Only docs/workflow-metadata	Skipped (paths-ignore)	Runs → success	success (from skip)
Only action source	Runs full e2e	Skipped (paths)	success/failure (from real)
Mixed (docs + code)	Runs full e2e	Also runs → success	Real is last write — wins

The mixed case is benign because the skip workflow finishes in ~30s while the real run takes ~3min, so the real result is always the last write to the commit status. (Even in the unlikely race where skip wrote last, GitHub recomputes mergeability on each status update — the real workflow's eventual write would still settle the merge gate.)

Compatibility & impact

Breaking changes

• None.

CI impact

• Saves ~5 min × ~5 docs/workflow-only PRs/month ≈ 25 minutes/month of e2e runtime.
• Eliminates the "pending Build & Test" perception on workflow-only PRs (this exact issue manifested on ci: switch CodeQL to advanced setup with JS/TS, same-repo and fork PR scanning #99 today).
• No change for PRs touching action source.

Status-context identity

Confirmed: the ruleset rule is required_status_checks: [{context: "all-tests-passed", integration_id: 15368}] — integration_id: 15368 is the GitHub Actions app, and both workflows post via set-commit-status-action using ${{ secrets.GITHUB_TOKEN }}, so the status integration_id matches.

Verification

After merge, expected behavior on a docs-only PR:

• Build & Test / build-dist, test-* checks: not present (skipped).
• Build & Test / all-tests-passed check: present and green (from skip workflow).
• Commit status all-tests-passed: success.
• Ruleset gate: satisfied.

On a source-only PR, behavior is unchanged.

Checklist

• paths-ignore covers only files that demonstrably cannot affect runtime
• build-and-test.yml itself is excluded from the ignore list (test changes still run)
• Paired skip workflow shares name: Build & Test for status-context identity
• Skip workflow uses the same set-commit-status-action and context name as the real one
• Mixed-path race condition analyzed and documented as benign
• After merge, verify on a doc-only follow-up PR that all-tests-passed is reported by the skip workflow

[ricogu]

@mdanish98 . please kindly help do a review, thanks!

[mdanish98]

lgtm!