Contributing

The source is on GitHub. The guidelines below are also in CONTRIBUTING.md.

Setting up

bash

pnpm install
pnpm build
pnpm test

Node.js 22.12 or newer and pnpm 11 are required.

Command	Purpose
`pnpm build`	Compile all packages.
`pnpm test`	Run unit and integration tests. Some use the built packages, so build first.
`pnpm test:browser`	Run tests in Chromium, Firefox and WebKit. Needs `pnpm build:all` and `pnpm browsers:install`.
`pnpm typecheck`	Check types everywhere.
`pnpm lint`	Run ESLint.
`pnpm format`	Run Prettier.
`pnpm docs:dev`	Run the documentation site.
`pnpm bench`	Run the benchmarks.
`pnpm changeset`	Describe your change for the changelog.

Keep parsing, resolution and printing separate.
Add utilities to the registry. The compiler doesn't know about specific utilities.
One name per concept. Don't add aliases. color and scale are the deliberate exceptions.
Add tests. A bug fix starts with a test that fails.
Update the docs in the same change as any public API.
Record significant decisions as an ADR in docs/adr.