Conventional Commits

conventional-commits

Write the message from the diff, not from the conversation. The reader is a stranger running git log in two years.

Procedure

1. Read what is actually staged: git diff --cached --stat then the diff itself.
2. Classify the change — pick ONE primary type:
   • feat new user-visible capability · fix corrects wrong behavior
   • refactor no behavior change · perf faster, same behavior
   • docs · test · build · ci · chore (only when nothing else fits)
3. Scope = the subsystem a reader would filter by: feat(parser): …. Omit if the repo doesn't use scopes (check git log --oneline -20 and match style).
4. Subject line: imperative, lowercase, no period, ≤ 72 chars, and it must state the effect, not the activity — "fix: reject expired tokens" not "fix: update token check".
5. Body (when the why isn't obvious): 1–3 sentences on why the change was needed and any non-obvious consequence. Wrap at 72. Never narrate the diff.
6. Breaking change → footer BREAKING CHANGE: <what breaks and the migration>, and add ! after the type: feat(api)!: ….

Anti-patterns to reject

• One commit doing two unrelated things — split it (git add -p).
• "update", "misc fixes", "address comments" — say what changed.
• Restating the conversation ("as discussed…") — the log has no conversation.
• Explaining that the change is correct — that belongs in the PR, not the log.

Example

fix(ingest): treat mtime regressions as edits, not new files

Restored backups can move mtime backwards; we indexed those as fresh
documents, duplicating every chunk. Key on inode+path instead.