mini-tsdown

A minimal TypeScript library bundler built with Rolldown and Oxc, created for learning purposes.

Features

• 🚀 Fast bundling - Powered by Rolldown (Rust-based bundler)
• 📦 Multi-format output - ESM and CJS
• 📝 Type declarations - Automatic .d.ts generation
• 👀 Watch mode - Rebuild on file changes
• 🔌 Hook system - Customize build lifecycle
• ⚙️ Config file support - .ts, .js, .json

Installation

pnpm add -D mini-tsdown

Usage

CLI

# Basic usage
npx mini-tsdown src/index.ts

# With options
npx mini-tsdown src/index.ts --format esm --format cjs --dts

# Watch mode
npx mini-tsdown src/index.ts --watch

CLI Options

| Option | Description | |--------|-------------| | -o, --out-dir <dir> | Output directory (default: dist) | | -f, --format <format> | Output format: esm or cjs | | --dts | Generate TypeScript declarations | | --sourcemap | Generate sourcemap | | --minify | Minify output | | -w, --watch | Enable watch mode | | --external <pkg> | Mark packages as external |

Configuration

Create mini-tsdown.config.ts in your project root:

import { defineConfig } from 'mini-tsdown'

export default defineConfig({
  entry: 'src/index.ts',
  outDir: 'dist',
  format: ['esm', 'cjs'],
  dts: true,
  sourcemap: true,
  external: ['some-external-package'],

  // Lifecycle hooks
  hooks: {
    'build:prepare': (ctx) => {
      console.log('Building...', ctx.options.entry)
    },
    'build:done': () => {
      console.log('Build complete!')
    },
  },
})

Programmatic API

import { build, defineConfig } from 'mini-tsdown'

await build({
  entry: 'src/index.ts',
  format: ['esm', 'cjs'],
  dts: true,
})

Hooks

mini-tsdown provides three lifecycle hooks:

| Hook | Description | |------|-------------| | build:prepare | Called before any build starts | | build:before | Called before each Rolldown build | | build:done | Called after build completes |

Project Structure

src/
├── cli.ts      # CLI entry point
├── index.ts    # Core build logic
├── config.ts   # Config file loader
├── hooks.ts    # Hook system
├── types.ts    # TypeScript definitions
└── main.ts     # Public API exports

Build mini-tsdown with itself

pnpm build

This will:

1. Build src/main.ts → dist/main.mjs + dist/main.d.mts
2. Build src/cli.ts → dist/cli.mjs

License

MIT