Javascript Modules CommonJS and ES6

EcmaScript Modules (ESM)

• from ES2005, Javascript supports modules
• uses export keyword and import
• in node .mjs extenstions are supported

lib.js:

export function hello () {
  console.log("hello world");
}
packagel.json
{
  "name":"es-modules",
   "type":"module"
}

main.js:

import { hello } from './lib.js';

hello();

running:

node main.js

bundling to out.js:

esbuild --bundle --outfile=out.js main.js
node out.js

CommonJS Modules (CJS)

• used in node
• uses require and module.exports

lib.js:

function add (a, b) { return a + b }
function minus (a, b) { return a + b }

module.exports = { add, minus };

main.js

const  { add, minus }  = require('./lib');

sources: - https://www.sitepoint.com/understanding-module-exports-exports-node-js/ - https://2ality.com/2019/04/nodejs-esm-impl.html

id: bt-20200424gcoe