unenv

unenv provides polyfills to add Node.js compatibility for any JavaScript runtime, including browsers and edge workers.

🌟 Used by

• Nitro
• Nuxt
• Cloudflare
• ESM.sh

Usage

The defineEnv utility can generate a target environment configuration.

import { defineEnv } from "unenv";

const { env } = defineEnv({
  nodeCompat: true,
  npmShims: true,
  resolve: true,
  overrides: {},
  presets: [],
});

const { alias, inject, external, polyfill } = env;

You can then integrate the env object with your build tool:

Options

• nodeCompat: (default: true)
  • Add alias entries for Node.js builtins as <id> and node:<id>.
  • Add inject entries for Node.js globals global, Buffer, and process.
• npmShims: (default: false)
  • Add alias entries to replace npm packages like node-fetch with lighter shims.
• resolve: (default: false) Resolve config values to absolute paths.
• overrides: Additional overrides for env config.
• presets: Additional presets (for example @cloudflare/unenv-preset).

unenv/ polyfills

You can also directly import unenv/ polyfills:

Node.js compatibility

unenv replaces Node.js built-in modules compatible with any runtime (view source).

Manual mocking

// Magic proxy to replace any unknown API
import MockProxy from "unenv/mock/proxy";

// You can also create named mocks
const lib = MockProxy.__createMock__("lib", {
  /* overrides */
});

(view source)

Nightly release channel

You can use the nightly release channel to try the latest changes in the main branch via unenv-nightly.

{
  "devDependencies": {
    "unenv": "npm:unenv-nightly"
  }
}

{
  "resolutions": {
    "unenv": "npm:unenv-nightly"
  }
}

License

Published under the MIT license. Made by @pi0 and community 💛