@o3osatoshi/config

Shared configuration for my TypeScript projects.

• tsup presets (browser/public-dual/functions)
• TypeScript tsconfig bases (base/node/browser/next/functions/storybook)
• Biome shared configs (base, react, next)
• ESLint flat config (perfectionist import/order rules)

Exports

• @o3osatoshi/config/tsup
• @o3osatoshi/config/tsconfig/*
• @o3osatoshi/config/biome/*
• @o3osatoshi/config/eslint/*

Installation

pnpm add -D @o3osatoshi/config

# Optional peers (depending on what you use)
# - For tsup presets / tsconfig usage
pnpm add -D tsup typescript
# - For ESLint flat config
pnpm add -D eslint @typescript-eslint/parser eslint-plugin-perfectionist

Notes

• Requires Node >= 22 (matches this repo engines).

Usage

tsup presets

Import presets from @o3osatoshi/config/tsup and export a config in tsup.config.mjs.

import { browserBundlePreset, publicDualBundlePreset, functionsBundlePreset } from "@o3osatoshi/config/tsup";

// Browser/React library (ESM, externals React/Next). DTS optional via { dts: true }.
export default await browserBundlePreset({ entry: { index: "src/index.tsx" }, dts: true });

// Public library (ESM + CJS, with DTS).
//    Default sourcemap: enabled in production/CI, disabled in dev.
// export default await publicDualBundlePreset({ entry: { index: "src/index.ts" } });

// Firebase Functions (ESM, Node target). Adjust target per runtime.
// export default await functionsBundlePreset({ entry: { index: "src/index.ts" } });

Notes

• Externals are automatically derived from dependencies/peerDependencies of the nearest package.json. In addition, common UI libs are always externalized: react, react-dom, next.
• The browser bundle preset explicitly marks React/Next as externals for UI packages.
• Each preset accepts standard tsup Options and sets sensible defaults.
• publicDualBundlePreset enables sourcemap by default in production/CI; pass { sourcemap: false } to disable.
• You can pass through env, banner, external, outDir, and onSuccess as needed.

Defaults (high-level)

• browserBundlePreset: ESM, platform browser, React/Next external, dts off by default.
• publicDualBundlePreset: ESM + CJS, DTS on, sourcemap on in CI/prd, off in dev.
• functionsBundlePreset: ESM, platform node, target: node22, sourcemap enabled.

tsconfig bases

Pick a base that fits your project (TS 5+, moduleResolution: "Bundler").

// Node/Library (default)
{
  "extends": "@o3osatoshi/config/tsconfig/node.json"
}

// Next.js app
{
  "extends": "@o3osatoshi/config/tsconfig/next.json"
}

// Browser library (React/Vite)
{
  "extends": "@o3osatoshi/config/tsconfig/browser.json"
}

// Firebase Functions (typecheck‑only; output is handled by your bundler)
{
  "extends": "@o3osatoshi/config/tsconfig/functions.json"
}

// Storybook (React + Vite)
{
  "extends": "@o3osatoshi/config/tsconfig/storybook.json"
}

ESLint (flat config)

This package ships a small ESLint flat-config focused on import/export/property sorting via eslint-plugin-perfectionist.

Usage in a project root eslint.config.mjs:

import config from "@o3osatoshi/config/eslint/config.mjs";

export default [...config];

What it does

• Registers @typescript-eslint/parser for TS files.
• Enables perfectionist rules for sorting imports/exports/objects, etc.
• Adds JSX prop sorting for React files.
• Ignores common output folders: dist, .next, .turbo, storybook-static, etc.

Peer deps

• eslint >= 9
• @typescript-eslint/parser
• eslint-plugin-perfectionist

Biome (shared config)

This package also exports a shared Biome configuration so multiple repositories can share the same lint/format rules.

Usage in another repository:

1. Install the package as a dev dependency.

   pnpm add -D @o3osatoshi/config

2. Create biome.json at the repository root and extend the shared config (using the package export):

   {
     "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
     "extends": ["@o3osatoshi/config/biome/base.json"]
   }

3. (Recommended) Mark it as the root config so Biome doesn’t traverse upward:

   {
     "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
     "root": true,
     "extends": ["@o3osatoshi/config/biome/base.json"]
   }

Variants (optional)

If you need different presets for specific contexts, you can publish additional files under packages/config/biome/ and extend them from the package export. This repo currently ships:

• @o3osatoshi/config/biome/base.json (common base)
• @o3osatoshi/config/biome/react.json (additional React/JSX rules)
• @o3osatoshi/config/biome/next.json (Next.js recommended rules)

Example: For a React project that also uses Next.js, extend both react.json and next.json.

{
  "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
  "extends": ["@o3osatoshi/config/biome/react.json", "@o3osatoshi/config/biome/next.json"]
}

Within this monorepo, the root already extends @o3osatoshi/config/biome/base.json.

What it enforces

• Base: double quotes (formatter), space indentation, import/key sorting, recommended rules, Project/Test domains.
• React: detect duplicate JSX props (noDuplicateJsxProps); sort class names for clsx/cva/tw (useSortedClasses).
• Next: enable next domain recommended rules.

Ready-made variants

• Next.js app:

  {
    "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
    "extends": ["@o3osatoshi/config/biome/react.json", "@o3osatoshi/config/biome/next.json"]
  }

Publishing

• Build: pnpm build (generates dist/)
• Publish to npm: pnpm publish --access public

The package exposes tsup presets, tsconfig, biome, and eslint exports. Install it as a dev dependency and import what you need per project.