Illusionist

Illusionist will make you believe ES6 is already available in browsers

Installation

$ npm install -g illusionist

Command-line

Usage: illusionist [options] [< in [> out]]
                   [file|dir ...]

  Options:

    -h, --help         Display help information
    -m, --module-name  Module name for stdin
    -M, --module-type  Module type [default: amd] (Options: amd, cjs, globals)
    -o, --out <dir>    Output to <dir> when passing files
    -v, --version      Display the version of Illusionist
    -w, --watch        Watch file(s) for changes and re-compile

STDIO Transpilation Example

Illusionist reads from stdin and outputs to stdout:

$ illusionist < es6-file.js > es5-file.js

You can also test transpilation right in the terminal. Type Ctrl-D for EOF.

$ illusionist
class Foo {
  constructor() {
    console.log('Foo');
  }
}

Compiling files and directories

Illusionist also accepts files and directories.

This would compile files in assets/javascripts to public/javascripts

illusionist assets/javascripts --out public/javascripts

You can also pass multiple paths:

illusionist foo-1.js foo-2.js some-folder/ --out public/

Compiling a directory tree

Say you have a structure like this:

/my-app/app/assets/javascripts
├── application.js
├── components
│   └── foo_component.js
├── controllers
│   └── foo_controller.js
└── models
    └── foo.js

You can keep this structure when outputing to the --out directory with:

illusionist --tree --out public/ app/assets/javascripts/

Node module

The module can take 3 options:

• moduleName - defines the AMD module name.
  Passing this option will ignore fileName and basePath.
• fileName - path to the file, used to define the AMD module name
• basePath - when passing basePath and fileName, the AMD module name will be fileName relative to basePath

// Module will be named 'controllers/foo_controller'
illusionist(stringOfES6, {moduleName: 'controllers/foo_controller'}).render();

// Module will be named 'controllers/foo_controller'
illusionist(stringOfES6, {
  basePath: '/Volumes/mirego/MyApp/assets/js/',
  fileName: '/Volumes/mirego/MyApp/assets/js/controllers/foo_controller.js'
}).render();

// Module will be named 'foo_controller'
illusionist(stringOfES6, {
  fileName: '/Volumes/mirego/MyApp/assets/js/controllers/foo_controller.js'
}).render();

Async version

var illusionist = require('illusionist');
illusionist(stringOfES6, {fileName: 'outputFileName.js'}).render(function(err, stringOfES5) {
  // yay we have ES5 code!
});

Sync version

var illusionist = require('illusionist');
var es5Code = illusionist(stringOfES6, {fileName: 'outputFileName.js'}).render();

Supported ES6 features

Illusionist is really just a wrapper for jstransform and es6-module-transpiler.
So for now, the features are:

Arrow functions

$('#element').on('click', (e) => {
  // `this` refers to the parent scope
});

class, extends, super and short method definitions

class Triangle extends Polygon {
  constructor(sides) {
    this.sides = sides;
    super();
  }
 
  render() {
    // ...
    super.render();
  }
}

Object short notation

function foo(x, y) {
  return {x, y}; // => {x: x, y: y}
};
 
function init({port, ip, coords: {x, y}}) {}

Rest parameters

function myConsole(...args) {
  console.log.apply(console, args);
}

Templates

var foo = `
  <div>Hello ${this.name.toUpperCase()}!</div>
  <div>This is nice</div>
`;

import, export and module

Note that for the time being, all modules are transpiled to AMD.

Named Exports

You can export specific variables:

// foobar.js
var foo = "foo", bar = "bar";
export { foo, bar };
 
// OR
 
export var foo = "foo";
export var bar = "bar";

And import them like this:

import { foo, bar } from 'foobar';

Default Exports

You can export a default export:

// jquery.js
var jQuery = function() {};
 
jQuery.prototype = {
  // ...
};
 
export default = jQuery;

And import it like this:

import $ from 'jquery';

Other syntax

Whereas the import keyword imports specific identifiers from a module, the module keyword creates an object that contains all of a module’s exports:

module foobar from 'foobar';
console.log(foobar.foo);

Rails Asset Pipeline

If you wish to use Illusionist in your Ruby on Rails project, you can easily do so by using the sprockets-illusionist gem which will seamlessly compile .js.es6 files to .js files.

License

Illusionist is © 2014 Mirego and may be freely distributed under the New BSD license.
See the LICENSE.md file.

About Mirego

Mirego is a team of passionate people who believe that work is a place where you can innovate and have fun. We’re a team of talented people who imagine and build beautiful Web and mobile applications. We come together to share ideas and change the world.

We also love open-source software and we try to give back to the community as much as we can.