/nodejs-require-to-import-converter

Convert your NodeJS sources from a require dynamic usage => to static imports ✨

Primary LanguageTypeScript

NodeJS require to import converter

Assist you in require() to import usage

This is a dumb project... which could make you win a lot of time ⏳ You are in the situation where:

  • You've got a legacy NodeJS project in Javascript

    • tons of module.exports 🕸,
    • with tons of require() 🕸

  • You want to improve by:

    • switching to Typescript with allowJs ✨ (or by switching to Ts at once!)
    • taking benefit of ES import interdependency fix unlike CommonJS

This script will (try to) handle all basic replacements to make a big change at once 🚀

About Dynamic / static

One of the main difference between NodeJs and Typescript is:

  • NodeJS can import modules dynamically
  • Typescript module relied on static ES6 modules definition

The update will be a required step to Typescript, so do it! One important thing is you have to do all at once (or on standalone modules)

  • use only require() / module.exports 🚫
  • or only import / export 🚫

The purpose of this script is to make you FAST in this mission 🚀

How to use

Install and run:

npm i
node ./dist/main.js /path/to/your/project
# Follow the instructions, step by step

Watch changes and test

Your project has to be on Git. Use your file editor to see if the script worked as expected.

Package config

Two steps are mandatory to use import in Nodejs:

  1. All "type":"module" to your package.json
  2. Run your node program with node --es-module-specifier-resolution=node

Step 2 is required in order to not specify file extension in imports, which is more common to switch to Typscript. By not writing extension, you will be able to switch a file ext from .js to .ts and not update every imports.

Eslint

Add to you eslint config file

"parserOptions": {
    "ecmaVersion": 2020,
    "sourceType": "module"
},

Capacities

Import support

🕸 CommonJS version

// Global imports
const _ = require('lodash');
const sinon = require('sinon');
const { ObjectId } = require('mongodb');
const CustomNameRouter = require('express').Router;

// Local imports
const someFile = require(`../path/file`);
const myFunc = require(`../file2`).func;
const { myUtil } = require(`../file2`);

✨ ES6 import version

// Global imports
import _ from 'lodash';
import * as sinon from 'sinon';
import { ObjectId } from 'mongodb';
import { Router as CustomNameRouter } from 'express';

// Local imports
import * as someFile from "../path/file.js";
import { func as myFunc, myUtil } from "../file2.js";

Export support

Exports

🕸 CommonJS version

const MYCONST = 89;
module.exports = { myFunc, MYCONST };
Object.assign(module.exports, { myFunc, MYCONST });
module.exports.someConst = {};
function myFunc(){}

✨ ES6 import version

export const MYCONST = 89;
export const someConst = {};
export function myFunc(){}

Handle index.js interface import / export

It's usual with Nodejs to have index.js files export like this:

🕸 CommonJS version

const myLib = require('./myLib');
const lib2 = require('./lib2/');
module.exports = { ...myLib, lib2, }

✨ ES6 import version

export * from './myLib.js';
export lib2 from './lib2/index.js';