tiny-pattern-ts/AGENTS.md

AGENTS.md

Machine entry point for AI coding agents working in this repo. The authoritative guidance for humans lives in CONTRIBUTING.md and README.md; this file only points at it and states the stable first-action facts. Do not restate evolving prose here — it will drift.

First action

• Project: F#-style pattern matching for TypeScript/ESM. Node >=26 (pinned via .node-version), ESM-only (no CommonJS shim).

• Mandatory while iterating: npm run test (runs check:tsc, then the unit suite). This is the gate you are responsible for.

• On commit: write a good message (see CONTRIBUTING.md § Commit messages). Lefthook's pre-commit hook already runs the fast, offline, staged-file checks (tsc + oxlint + oxfmt + cspell) — don't run them by hand. If the hook fails on style, npm run fix, restage, recommit.

• Optional final gate: npm run check (the fast, offline, whole-project correctness ladder: tsc → oxlint → oxfmt → cspell). Safe to run whenever you want a project-wide confirmation; pre-commit already covers staged files.

• npm run maintain is NOT part of the feature loop. maintain:knip (dead-code/deps) and maintain:outdated (registry) are advisory maintenance scans. Run them only on an explicit maintenance / update-deps branch; CI surfaces them via a non-blocking job, never as a gate.

  npm run test    # mandatory gate
  npm run check   # optional project-wide confirmation
  

  The bot's definition of done: npm run test green, commit normally after.

Never do

Don't silence the type system to force a green run. As an agent these are forbidden:

• // @ts-nocheck, // @ts-ignore, // @ts-expect-error
• // oxlint-disable / // oxlint-disable-next-line
• as casts used to push an expression through (type-aware oxlint already flags unsafe assertions)

Fix the root cause with the type system instead — narrowing, generics, satisfies, conditional / mapped types, utility types (NonNullable, Exclude, …). TypeScript can express it; that's the intended tool. The oxlint-disable-location rule in CONTRIBUTING.md § Rules the tools don't enforce is a human last-resort convention (so a reviewer can spot a deliberate suppression) — it is not permission for you to add one. If the types genuinely cannot express something, stop and surface the conflict (commit message / MR) rather than suppress it.

The same applies to the checks themselves: never git commit --no-verify (or otherwise skip a pre-commit / pre-push hook). The checks are fast and offline, so a redundant run is fine — bypassing a hook to get green is the identical anti-pattern. If a commit already skipped a hook, redo it through one: git reset --soft HEAD~1 && git commit -C <skipped-sha>.

Read these

• CONTRIBUTING.md § Rules the tools don't enforce — the constraints the linters don't catch; CI/review bounce these. The most important section.
• CONTRIBUTING.md § Script prefix convention — adding an npm run script? reuse an existing prefix or it doesn't belong.
• CONTRIBUTING.md § Commit messages — gitmoji + imperative + 50/72.
• CONTRIBUTING.md § Feedback tiers — what runs when (watch / pre-commit / pre-push / check / fix / CI).
• README.md § Tooling decisions — the rationale behind each tool choice; read before changing tooling.
• package.json #scripts — the source of truth for every command (the LEFTHOOK_FILES convention scopes them to staged files vs. the whole project).