DEV Community

Lukas Gaucas
Lukas Gaucas

Posted on


CJS's __dirname & __filename for ESM – beginners friendly constants

Okay, you switched from CJS to more standard of ES6, you potentially lost ability to use __constants such as __dirname (most often used) or __filename , you need mock ones from ESM perspective, let's make default export utility lib :

// Within esm-constants.js do :
export default (function(){
import path, {dirname} from 'path';
import {fileURLToPath} from 'url';
const __filename = fileURLToPath(import.meta.url)
const __dirname = dirname(__filename)

// At the very top of some-other-module.js scope do the following: 
// import './path/to/esm-constants.js'
Enter fullscreen mode Exit fullscreen mode

That's it , you're ready to go !

p.s. this snippet flows around web for a while, just tried to capture & emphasize this as a MUST listing in Node-series of mine.

Thanks & see you in the next one !

Top comments (0)

🌚 Friends don't let friends browse without dark mode.

Sorry, it's true.