# Github CI Guardrails

> Validate merge readiness with atomic commits and GitHub Actions checks using gh CLI; use for pre-merge verification and CI truth validation.

- Skill: `d-o-hub/github-ci-guardrails` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add d-o-hub/github-ci-guardrails`
- Raw SKILL.md: https://api.skillmd.com/api/skills/d-o-hub/github-ci-guardrails/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: d-o-hub (https://skillmd.com/u/d-o-hub)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/d-o-hub/github-ci-guardrails

---


# GitHub CI Guardrails

1. Ensure change set is one logical unit (atomic commit).
2. Run local gates from `references/local-gates.md`.
3. **Commitlint full PR range** before push:
   `npx commitlint --from origin/main --to HEAD --verbose`
4. Validate GitHub checks with `references/gh-ci-truth.md`.
5. If checks fail, report failing job and log URL; map failure class via
   `references/ci-pitfalls-pr-triage.md` (commitlint scope, mutation surface,
   clippy `duplicated_attributes`, Jules force-push regression).
6. Do not claim green until `gh pr checks` shows no failures.

## Mutation gate (fast in-diff)

- Score = killed / (killed + missed); threshold typically 85% (`MUTATION_THRESHOLD`).
- **Minimize unrelated churn** in the PR diff — cosmetic rewrites of adjacent
  functions put them in the mutant set (e.g. `import_json -> Ok(1)` survives a
  test that only imports one concept).
- **Kill comparison boundary mutants** when using `select_nth_unstable_by(k)`:
  test the `len == k` path so `>` → `>=` panics and is caught.
- **CLI async entry points** (`run_query -> Ok(())`) are usually unkillable under
  `--lib`-only mutation CI; prefer exclude in `scripts/mutation_test.sh` with a
  one-line rationale, not path-excluding whole production modules.

## Pre-merge re-check (multi-PR or bot PRs)

```bash
git fetch origin main
git diff --stat origin/main...HEAD   # unexpected reverts?
npx commitlint --from origin/main --to HEAD --verbose
gh pr checks <n>
```