ES modules in Node.js (basic idea)

cjs-module.js

// Import CJS module
const otherCJSModule = require('./other-cjs-module');

// Import ES module, relying on upcoming standard
import('./es-module').then(function (esModule) {
 ...
});
 
// Import core module
const fs = require('fs');

es-module.js

// Import ES module
import * from './other-es-module';

// Import CJS module
// This may need to look a bit different, as 'require' is expected to be different function
// in each module that imports it
import { require } from 'nodejs';
const cjsModule = require('./cjs-module');

// Import core module
import fs from 'fs';

initialization.md

Run CJS module

node cjs-module.js

Run ES module

node --esm es-module.js

Or introduce other binary:

nodejs es-module.js

(Possibly with some major Node.js version ES module could start being default)