Bublé

input

 
/*
  Thanks for trying Bublé! Quickstart:
​
  $ npm install -g buble
  $ echo "const answer = () => 42" > input.js
  $ buble input.js > output.js
  $ cat output.js
​
  This is a relatively new project – please report
  any bugs you find by clicking 'report bugs' and
  linking to a version of this page demonstrating
  the issue. Thanks!
​
  Note that some ES2015 features are deliberately
  unsupported - click the 'guide' link in nav.
*/
​
// arrow functions
const add = ( a, b ) => a + b;
​
// classes
class Circle extends Shape {
  constructor ( radius ) {
    super();
    this.radius = this;
  }
​
  area () {
    return Math.PI * Math.pow( this.radius, 2 );
  }
}
​
// object literals
let obj = {
  shorthandProperty,
  shorthandMethod () {
    console.log( 'hello!' );
  },
  [computed]: 42
};
​
// template strings
let message = `
  hello ${name}!
  it's good to see you`;
​
// destructuring
let { x, y } = point;
let { top, left } = element.getBoundingClientRect();
let [ one, two, three ] = document.querySelectorAll( 'p' );
​
// default parameters
function foo ( options = {} ) {
  if ( options.bar ) alert( options.baz );
}
​
// rest parameters
function sprintf ( str, ...values ) {
  return str.replace( /%(w+)/g, ( match, type ) => {
    return format( values.shift(), type );
  });
}
​
// spread operator
var max = Math.max( ...values );
​
// block scoping
for ( let i = 0; i < 10; i += 1 ) {
  const square = i * i;
  setTimeout( () => console.log( square ), i * 100 );
}
​
// binary and octal literals
0b101010 === 0o52;

output

 
/*
  Thanks for trying Bublé! Quickstart:
​
  $ npm install -g buble
  $ echo "const answer = () => 42" > input.js
  $ buble input.js > output.js
  $ cat output.js
​
  This is a relatively new project – please report
  any bugs you find by clicking 'report bugs' and
  linking to a version of this page demonstrating
  the issue. Thanks!
​
  Note that some ES2015 features are deliberately
  unsupported - click the 'guide' link in nav.
*/
​
// arrow functions
var add = function ( a, b ) { return a + b; };
​
// classes
var Circle = (function (Shape) {
  function Circle ( radius ) {
    Shape.call(this);
    this.radius = this;
  }
​
  if ( Shape ) Circle.__proto__ = Shape;
  Circle.prototype = Object.create( Shape && Shape.prototype );
  Circle.prototype.constructor = Circle;
​
  Circle.prototype.area = function area () {
    return Math.PI * Math.pow( this.radius, 2 );
  };
​
  return Circle;
}(Shape));
​
// object literals
var obj = {
  shorthandProperty: shorthandProperty,
  shorthandMethod: function shorthandMethod () {
    console.log( 'hello!' );
  }
};
obj[computed] = 42;
​
// template strings
var message = "\n  hello " + name + "!\n  it's good to see you";
​
// destructuring
var x = point.x;
var y = point.y;
var ref = element.getBoundingClientRect();
var top = ref.top;
var left = ref.left;
var ref$1 = document.querySelectorAll( 'p' );
var one = ref$1[0];
var two = ref$1[1];
var three = ref$1[2];
​
// default parameters
function foo ( options ) {
  if ( options === void 0 ) options = {};
​
  if ( options.bar ) { alert( options.baz ); }
}
​
// rest parameters
function sprintf ( str ) {
  var values = [], len = arguments.length - 1;
  while ( len-- > 0 ) values[ len ] = arguments[ len + 1 ];
​
  return str.replace( /%(w+)/g, function ( match, type ) {
    return format( values.shift(), type );
  });
}
​
// spread operator
var max = Math.max.apply( Math, values );
​
// block scoping
var loop = function ( i ) {
  var square = i * i;
  setTimeout( function () { return console.log( square ); }, i * 100 );
};
​
for ( var i = 0; i < 10; i += 1 ) loop( i );
​
// binary and octal literals
42 === 42;