esnext 

Bring your JavaScript into the future.

Installation

``
$ yarn global add esnext


or, with npm:


$ npm install -g esnext
`

Usage

After installing, run esnext -h for comprehensive usage instructions.

Features

$3

Translate some regular functions to arrow functions:

`js
list.map(function(item) { return item.name; });

// ↑ becomes ↓

list.map(item => item.name);
`

$3

Convert var declarations to let or const as appropriate:

`js
var arr = [];
for (var i = 0; i < 5; i++) {
arr.push(i);
}

// ↑ becomes ↓

const arr = [];
for (let i = 0; i < 5; i++) {
arr.push(i);
}
`

$3

Use shorthand syntax for various object constructs:

`js
let person = {
first: first,
last: last,

fullName: function() {
return ${first} ${last};
}
};

// ↑ becomes ↓

let person = {
first,
last,

fullName() {
return ${first} ${last};
}
};
`

$3

Convert string concatenation to string or template literals:

`js
let name = 'Brian' + ' ' + 'Donovan';
let greeting = 'Hello, ' + name;

// ↑ becomes ↓

let name = 'Brian Donovan';
let greeting = Hello, ${name};
`

$3

Convert assignments and declarations to use object destructuring syntax:

`js
let a = obj.a, b = obj.b;
a = obj2.a, b = obj2.b;

// ↑ becomes ↓

let { a, b } = obj;
({ a, b } = obj2);
`

$3

Translate CommonJS modules into ES6 modules:

`js
var readFile = require('fs').readFile;
const MagicString = require('magic-string');
let { ok, strictEqual: eq } = require('assert');

exports.doSomething = function() {
ok(1);
};

// ↑ becomes ↓

import { readFile } from 'fs';
import MagicString from 'magic-string';
import { ok, strictEqual as eq } from 'assert';

export function doSomething() {
ok(1);
}
`

Options

`js
{
'declarations.block-scope': {
/**
* Set this to true to only turn var into let, never const.
*/
disableConst: boolean
}
}
``