@vrowzer/node-polyfill

Browser-compatible Node.js module polyfills for vrowzer.

Features

• Individual subpath exports for tree-shaking
• Browser / Service Worker ready
• Full EventEmitter with Node.js v23+ features
• ANSI cursor/clear functions for readline
• Promise-based timer APIs with AbortSignal support
• TypeScript support with full type definitions

💿 Installation

# npm
npm install --save @vrowzer/node-polyfill

# pnpm
pnpm add @vrowzer/node-polyfill

# yarn
yarn add @vrowzer/node-polyfill

# deno
deno add npm:@vrowzer/node-polyfill

# bun
bun add @vrowzer/node-polyfill

🚀 Usage

Direct Usage

import { EventEmitter, once, on } from '@vrowzer/node-polyfill/events'
import { clearLine, cursorTo, createInterface } from '@vrowzer/node-polyfill/readline'
import { setTimeout as delay } from '@vrowzer/node-polyfill/timers/promises'

const ee = new EventEmitter()
ee.on('data', msg => console.log(msg))
ee.emit('data', 'hello')

// Promise-based once
const [value] = await once(ee, 'result')

// Async timer
await delay(1000, 'done')

As Node.js Module Polyfill (Vite/Vitest/Rolldown)

// vite.config.ts / vitest.config.ts / rolldown.config.ts
export default defineConfig({
  resolve: {
    alias: {
      'node:url': '@vrowzer/node-polyfill/url',
      'node:util': '@vrowzer/node-polyfill/util',
      'node:events': '@vrowzer/node-polyfill/events',
      'node:perf_hooks': '@vrowzer/node-polyfill/perf_hooks',
      'node:os': '@vrowzer/node-polyfill/os',
      'node:dns': '@vrowzer/node-polyfill/dns',
      'node:dns/promises': '@vrowzer/node-polyfill/dns/promises',
      'node:process': '@vrowzer/node-polyfill/process',
      'node:readline': '@vrowzer/node-polyfill/readline',
      'node:timers': '@vrowzer/node-polyfill/timers',
      'node:timers/promises': '@vrowzer/node-polyfill/timers/promises'
    }
  }
})

API

Entry Points

| Entry Point | Node.js Module | Description | | ---------------------------------------- | ---------------------- | ------------------------------------------------------------------------------------------------- | | @vrowzer/node-polyfill/url | node:url | fileURLToPath, pathToFileURL, URL | | @vrowzer/node-polyfill/util | node:util | promisify, inspect, stripVTControlCharacters | | @vrowzer/node-polyfill/events | node:events | EventEmitter, once, on, addAbortListener, getEventListeners | | @vrowzer/node-polyfill/perf_hooks | node:perf_hooks | performance, PerformanceObserver, stubs for monitorEventLoopDelay, createHistogram | | @vrowzer/node-polyfill/os | node:os | endianness, hostname, platform, availableParallelism, stubs for getPriority, userInfo | | @vrowzer/node-polyfill/dns | node:dns | Stub implementations for all DNS APIs | | @vrowzer/node-polyfill/dns/promises | node:dns/promises | Promise-based DNS stubs | | @vrowzer/node-polyfill/process | node:process | cwd/chdir, nextTick, hrtime, env, stdout/stderr/stdin stubs | | @vrowzer/node-polyfill/readline | node:readline | ANSI cursor/clear, Interface, promises API with Readline utility | | @vrowzer/node-polyfill/timers | node:timers | setTimeout/setInterval, setImmediate (MessageChannel fallback) | | @vrowzer/node-polyfill/timers/promises | node:timers/promises | Promise setTimeout/setImmediate, async iterator setInterval, scheduler |

Implementation Notes

Fully implemented (browser-native or equivalent):

• url - fileURLToPath/pathToFileURL with Windows path support
• events - Complete EventEmitter with captureRejections, errorMonitor, async once/on, addAbortListener
• perf_hooks - Browser-native performance, PerformanceObserver via globalThis
• readline - ANSI escape sequences for terminal control, Interface with async iteration
• timers - Native re-exports with setImmediate polyfill via MessageChannel
• timers/promises - Promise/AsyncIterator APIs with AbortSignal support

Stub implementations (browser-safe defaults):

• os - Returns browser defaults (platform: 'browser', arch: 'javascript')
• dns - Returns stub values (127.0.0.1 for lookup, empty arrays for resolve*)
• process - Minimal process with cwd/chdir, env, nextTick, hrtime.bigint()

🤝 Sponsors

©️ License

MIT