5to6-codemod

A collection of codemods that allow you to transform your js code from ES5 to ES6 using jscodeshift.

Usage

1. npm install -g jscodeshift
2. npm install 5to6-codemod
3. jscodeshift -t node_modules/es6-codemod/transforms/[transform].js [files]
4. Review changes via git diff. Keep what you want, throw it out if you don't. Magic!

Transforms

• amd - Transforms AMD style modules to ES6 import/export
• cjs - Transforms CommonJS style require() calls to ES6 import statements
• no-strict - Removes "use strict" statements
• exports - Move CommonJS style module.exports statements to ES6 export statements
• let - Replace all var calls to use let

Known issues

• Currently loses comments if directly before the require() statement.
• require() calls in single var statements get reordered, and moved before the single var after conversion to import.
• Can't automagically figure out when you want to use import * as varName.
• End-of-line comments also missing in many situations

Appendix - Transforms In-Depth

CJS Transform

Before

var jamis = require('jquery');
var $ = require('jquery');
var $ = require("jquery");
require('something');

var foo = bar;

// some comment
var jamis = 'bar',
    _ = require('lodash'),
    lodash = require('underscore'),
    bar,
    foo = 'bar',
    $ = require('jquery');

var routeTo = require('../routeHelper').routeTo;
var fetch = require('../someUtil').pluck;

After

import jamis from 'jquery';
import $ from 'jquery';
import $ from 'jquery';
import 'something';

var foo = bar;

import _ from 'lodash';
import lodash from 'underscore';
import $ from 'jquery';

// some comment
var jamis = 'bar', bar, foo = 'bar';

import {routeTo} from '../routeHelper';
import {pluck as fetch} from '../someUtil';