Introduction

The import syntax is specific to ES6 Modules(introduced in ES2015) since JavaScript never had a package system besides the old <script></script>.

Nodejs uses Commonjs Pattern adopted as the de facto standard for using modules in Nodejs applications.

All code for this example can be found in: this repo

Using the import syntax

The import syntax is pretty intuitive. The syntax for import is:

// default
import utils from './utils'

// non-default multiple exports
import {parser, reader } from './utils'

Here’s how we can use the same syntax in Nodejs:

  1. In your package.json, add "type": "module"
{
  "name": "node-js-import-syntax",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "type": "module",
  "scripts": {
    "start": "node src/index.js"
  }
}
  1. Use the import/export syntax as you would in ES6 Modules:
import express from 'express'
// Note: remember to include the file extension (.js) for this to work!
import indexRouter from './router.js'

const app = express()
const PORT = process.env.PORT || 3000

// enable JSON parsing middleware to parse json.
app.use(express.json())
app.use('/index', indexRouter)

async function main() {
  app.listen(PORT, () => console.log('HTTP server up at PORT'))
}

main().catch((err) => console.error(err))

Inside router.js module:

import { Router } from 'express'

// create an Instance of the Router
const indexRouter = Router()

indexRouter.get('/', (req, res) => {
  res.json({ message: 'Hello Champ!' })
})

export default indexRouter

That’s how easy to use the import/export syntax in a Nodejs codebase!

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