Tooling

Linting and Formatting

This monorepo uses the Rust-based oxc toolchain:

• oxlint for linting, with the typescript, import, and unicorn plugins enabled.
• oxfmt for formatting.

Both are dramatically faster than the Prettier + ESLint or Biome alternatives I used previously, and oxlint provides reliable type-aware rules (notably typescript/no-misused-promises and typescript/no-explicit-any).

Configuration lives in:

• .oxlintrc.json
• .oxfmtrc.jsonc and .oxfmtignore

Scripts

Script	Description
lint	Run oxlint in type-aware mode with the import plugin
lint:fix	Same as lint, applying autofixes
format	Run oxfmt (writes changes)
check-format	Run oxfmt in check mode
check-lint	Build all packages first, then run oxlint (CI-equivalent check)

Type-aware lint requires the built .d.ts files of dependencies to be present, which is why check-lint builds first. Day-to-day you can just run lint — the IDE integration will have already warmed the caches.

Circular imports

Circular imports are caught by the import/no-cycle oxlint rule, so there is no separate madge pass. If you ever introduce a cycle, it will surface as a lint error at the root.

Git Hooks

Pre-commit hooks are managed by lefthook. The config in lefthook.yml runs two steps in parallel on staged files:

1. format — oxfmt with stage_fixed: true, so format corrections are automatically added to the commit.
2. lint — oxlint --import-plugin --type-aware, which will block the commit if there are lint errors.

The hook is installed automatically on pnpm install via the root prepare script (lefthook install). There is nothing else to configure.

Type checking and tests are not run pre-commit — they live in CI, where they can take the time they need. The pre-commit hook is intentionally kept fast enough to feel invisible.

Testing

This monorepo uses Vitest for testing. Tests can be run with:

pnpm test

A workspace configuration (vitest.workspace.ts) at the root ensures tests are discovered across all packages.

Build Orchestration

Turborepo orchestrates all tasks across the workspace. Task definitions live in turbo.jsonc. The main tasks are build, check-types, test, and clean; each declares its dependencies on upstream builds so Turborepo can schedule and cache correctly.

See Architecture for how these tasks fit together with the TypeScript project references used in the hybrid build approach.

Node Runtime

The Node version is pinned via .nvmrc and engines.node in the root package.json (currently Node 24). CI and the Firebase Functions runtimes are aligned to the same version.