ascjs

ascjs

ES2015 to CommonJS import/export transformer

---

This module does one thing only: it loosely transpiles ES2015 import/export statements into valid CommonJS in order to fix the only part of Node that's incompatible with modern JS.

Features

• extremely lightweight, based on cherow for performance and reliability, it transforms only imports/exports ignoring everything else
• produces modern JavaScript, you are in charge of extra transformations if needed
• indentation, spaces, semi or no-semi are preserved: beautiful source code remains beautiful
• uses same Babel convention, resolving export default ... intent as exports.default
• you can finally write .js code and transform it for Node only before publishing on npm
• you could write .mjs modules and transform them into CommonJS for Browserify or other bundlers as target

Constrains

• live bindings for exported values are not preserved. You need to delegate in scope eventual changes
• dynamic import(...) is untouched. If you write that, let Webpack handle it for you later on
• there is no magic whatsoever in module names resolution, what you write in ESM is what you get as CJS

Example

This module can transform the following ES2015+ code

import func, {a, b} from './module.js';
import * as tmp from 'other';

const val = 123;

export default function test() {
  console.log('ascjs');
};

export {func, val};

into the following one:

const func = (m => m.__esModule ? m : {default: m})(require('./module.js')).default;
const {a, b} = func;
const tmp = require('other');

const val = 123;

function test() {
  console.log('ascjs');
}
Object.defineProperty(exports, '__esModule', {value: true}).default = test;

exports.func = func;
exports.val = val;