Set up local dev tooling: lefthook pre-commit hooks + mise

[will-corrigan]

Problem

No pre-commit hooks means formatting/lint issues slip through to CI (or worse, get pushed). Tooling versions (Node, pnpm, Go) aren't pinned for local dev, leading to "works on my machine" issues.

Proposal

Lefthook for pre-commit hooks

• Run prettier --check on staged files
• Run eslint on staged files
• Run turbo type-check (or a lighter check) on affected packages
• Run glot lint / glot compat when lexicon files change

mise for tooling versions

• Pin Node, pnpm, and Go versions in .mise.toml
• Replaces ad-hoc version management
• Note: mise is for local dev only — Vercel manages its own Node version via engines in package.json / dashboard settings. No conflict.

Nice to haves

• Document setup in README/CONTRIBUTING
• Consider adding a pnpm prepare script to auto-install lefthook on pnpm install

[tom-sherman]

We can have pre commit hooks but personally I find negative value in them. If we add them they should be completely optional, so no "prepare" script.

[will-corrigan]

We can have pre commit hooks but personally I find negative value in them. If we add them they should be completely optional, so no "prepare" script.

Any particular reason other than you loving pushing commits to get yelled at by CI? 😂 Runs in like half a second and you don't even know it's happening most of the time.

[tom-sherman]

https://jyn.dev/pre-commit-hooks-are-fundamentally-broken/

[will-corrigan]

Lefthook addresses all of these. You can skip specific hooks during operations like rebase and merge so they never fire when they shouldn't, and you can glob hooks to specific file patterns so they only run when relevant files are actually staged. It also supports both pre-commit and pre-push so we can use whichever we prefer.

mise would only install the lefthook binary, and hooks aren't active unless you explicitly run lefthook install so opt in all you'd like I guess