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https://github.com/esnext/es6-module-transpiler

Tomorrow’s JavaScript module syntax today
https://github.com/esnext/es6-module-transpiler

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Tomorrow’s JavaScript module syntax today

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README 

        
# ES6 Module Transpiler [![Build Status](https://travis-ci.org/esnext/es6-module-transpiler.png)](https://travis-ci.org/esnext/es6-module-transpiler)



## NOTE: This project been deprecated in favor of Babel & Rollup.



This project is part of esnext, which has merged with [Babel]. All the features

of esnext are supported by Babel, and more. All the tests from esnext have been

ported over to Babel to ensure that switchers will have minimal code changes to

make. The maintainers of esnext will continue working on Babel to bring better

spec compliance, ES6 feature support, and performance. If you want a fast tool

with bundling support as found in this project, you should check out [Rollup].



---



ES6 Module Transpiler is an experimental compiler that allows you to write your

JavaScript using a subset of the ES6 module syntax, and compile it into AMD or

CommonJS modules.



This compiler provides a way to experiment with ES6 syntax in real world

scenarios to see how the syntax holds up. It also provides a nicer, more

declarative way to write AMD (or CommonJS) modules.



See the [CHANGELOG](./CHANGELOG.md) for the latest updates.



## Usage



### Build tools



The easiest way to use the transpiler is from an existing build tool. There

several plugins developed for different build tools:



* **Grunt:** [grunt-es6-module-transpiler](https://github.com/joefiorini/grunt-es6-module-transpiler), maintained by @joefiorini (not yet compatible with v0.5.x)

* **Gulp:** [gulp-es6-module-transpiler](https://github.com/ryanseddon/gulp-es6-module-transpiler), maintained by @ryanseddon

* **Brunch:** [es6-module-transpiler-brunch](https://github.com/gcollazo/es6-module-transpiler-brunch), maintained by @gcollazo *(CommonJS only)* (not yet compatible with v0.5.x)

* **Broccoli:** [broccoli-es6-concatenator](https://github.com/joliss/broccoli-es6-concatenator), maintained by @joliss (not yet compatible with v0.5.x)

* **Mimosa:** [mimosa-es6-module-transpiler](https://github.com/dbashford/mimosa-es6-module-transpiler), maintained by @dbashford (not yet compatible with v0.5.x)

* **AMD Formatter:** [es6-module-transpiler-amd-formatter](https://github.com/caridy/es6-module-transpiler-amd-formatter), maintained by @caridy (compatible with v0.5.x+ only)



### Executable



The transpiler can be used directly from the command line:



```

$ npm install -g es6-module-transpiler

$ compile-modules convert foo.js

```



Here is the basic usage:



```

compile-modules convert -I lib -o out FILE [FILE…]

```



### Library



You can also use the transpiler as a library:



```javascript

var transpiler = require('es6-module-transpiler');

var Container = transpiler.Container;

var FileResolver = transpiler.FileResolver;

var BundleFormatter = transpiler.formatters.bundle;



var container = new Container({

  resolvers: [new FileResolver(['lib/'])],

  formatter: new BundleFormatter()

});



container.getModule('index');

container.write('out/mylib.js');

```



## Supported ES6 Module Syntax



### Named Exports



There are two types of exports. *Named exports* like the following:



```javascript

// foobar.js

var foo = 'foo', bar = 'bar';



export { foo, bar };

```



This module has two named exports, `foo` and `bar`.



You can also write this form as:



```javascript

// foobar.js

export var foo = 'foo';

export var bar = 'bar';

```



Either way, another module can then import your exports like so:



```js

import { foo, bar } from 'foobar';



console.log(foo);  // 'foo'

```



### Default Exports



You can also export a *default* export. For example, an ES6ified jQuery might

look like this:



```javascript

// jquery.js

var jQuery = function() {};



jQuery.prototype = {

  // ...

};



export default jQuery;

```



Then, an app that uses jQuery could import it with:



```javascript

import $ from 'jquery';

```



The default export of the "jquery" module is now aliased to `$`.



A default export makes the most sense as a module's "main" export, like the

`jQuery` object in jQuery. You can use default and named exports in parallel.



### Other Syntax



#### `import "foo";`



A "bare import" that doesn't import any identifiers is useful for executing

side effects in a module. For example:



```js

// alerter.js

alert("alert! alert!");



// alertee.js

import "alerter";  // will pop up alert box

```



## Compiled Output



### Default Exports



This is super important:



**Default exports bind to an identifier on the module called `default`!**



Internally, the transpiler will use this default identifer when importing, but

any outside consumer needs to be aware that it should use the `default` key and

not the module itself. For example, a CommonJS consumer should look like this:



```js

var $ = require('jquery')['default'];

```



## Installation



Add this project to your application's package.json by running this:



    $ npm install --save es6-module-transpiler



Or install it globally:



    $ npm install -g es6-module-transpiler



## Acknowledgements



Thanks to [Yehuda Katz](https://twitter.com/wycats) for

[js_module_transpiler](https://github.com/wycats/js_module_transpiler), the

library on which this one is based. Thanks to [Dave

Herman](https://twitter.com/littlecalculist) for his work on ES6 modules.

Thanks to [Erik Bryn](https://twitter.com/ebryn) for providing the initial push

to write this library. Thanks to [Domenic

Denicola](https://twitter.com/domenic), [Jo Liss](https://twitter.com/jo_liss),

& [Thomas Boyt](https://twitter.com/thomasaboyt) for their efforts to make this

project even better. And finally thanks to the JavaScript community at Square

for helping to write and release this library.



## Contributing



1. Fork it

2. Create your feature branch (`git checkout -b my-new-feature`)

3. Commit your changes (`git commit -am 'Add some feature'`)

4. Push to the branch (`git push origin my-new-feature`)

5. Create new Pull Request



Any contributors to the master es6-module-transpiler repository must sign the

[Individual Contributor License Agreement (CLA)][cla].  It's a short form that

covers our bases and makes sure you're eligible to contribute.



[cla]: https://spreadsheets.google.com/spreadsheet/viewform?formkey=dDViT2xzUHAwRkI3X3k5Z0lQM091OGc6MQ&ndplr=1



When you have a change you'd like to see in the master repository, [send a pull

request](https://github.com/esnext/es6-module-transpiler/pulls). Before we merge

your request, we'll make sure you're in the list of people who have signed a

CLA.



Thanks, and enjoy living in the ES6 future!



[Babel]: https://babeljs.io/

[Rollup]: https://github.com/rollup/rollup