es6ify

browserify >=v2 transform to compile JavaScript.next (ES6) to JavaScript.current (ES5) on the fly.

browserify({ debug: true })
  .add(es6ify.runtime)
  .transform(es6ify)
  .require(require.resolve('./src/main.js'), { entry: true })
  .bundle()
  .pipe(fs.createWriteStream(bundlePath));

Find the full version of this example here.

Installation

npm install es6ify

What You Get

Try it live

<!-- START doctoc generated TOC please keep comment here to allow auto update --> <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->

Table of Contents generated with DocToc

• Enabling sourcemaps and related posts
• API
• Examples
  • es6ify.configure(filePattern : Regex)
  • es6ify.traceurOverrides
• Caching
• Source Maps
• Supported ES6 features
  • arrowFunctions
  • classes
  • defaultParameters
  • destructuring
  • forOf
  • propertyMethods
  • propertyNameShorthand
  • templateLiterals
  • restParameters
  • spread
  • generators
  • modules

<!-- END doctoc generated TOC please keep comment here to allow auto update -->

Enabling sourcemaps and related posts

• In Chrome or Firefox: enabled by default
• In IE: works in IE11 onward by default
• browserify-sourcemaps
• html5 rocks sourcemaps post

API

<!-- START docme generated API please keep comment here to allow auto update --> <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN docme TO UPDATE --> <div> <div class="jsdoc-githubify"> <section> <article> <div class="container-overview"> <dl class="details"> </dl> </div> <dl> <dt> <h4 class="name" id="e6ify::runtime"><span class="type-signature"></span>e6ify::runtime<span class="type-signature"></span></h4> </dt> <dd> <div class="description"> <p>The traceur runtime exposed here so it can be included in the bundle via:</p> <p><code>browserify.add(es6ify.runtime)</code></p> <p>The runtime is quite large and not needed for all ES6 features and therefore not added to the bundle by default. See <a href="https://github.com/google/traceur-compiler/issues/1007#issuecomment-42837067">this comment</a> for details.</p> </div> <dl class="details"> <dt class="tag-source">Source:</dt> <dd class="tag-source"><ul class="dummy"> <li> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js">index.js</a> <span>, </span> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js#L122">lineno 122</a> </li> </ul></dd> </dl> </dd> <dt> <h4 class="name" id="es6ify::traceurOverrides"><span class="type-signature"></span>es6ify::traceurOverrides<span class="type-signature"></span></h4> </dt> <dd> <div class="description"> <p>Allows to override traceur compiler defaults.</p> <p>In order to support async functions (<code>async</code>/<code>await</code>) do:</p> <p><code>es6ify.traceurOverrides = { asyncFunctions: true }</code></p> </div> <dl class="details"> <dt class="tag-source">Source:</dt> <dd class="tag-source"><ul class="dummy"> <li> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js">index.js</a> <span>, </span> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js#L139">lineno 139</a> </li> </ul></dd> </dl> </dd> </dl> <dl> <dt> <h4 class="name" id="es6ify"><span class="type-signature"></span>es6ify<span class="signature">()</span><span class="type-signature"> &rarr; {function}</span></h4> </dt> <dd> <div class="description"> <p>The es6ify transform to be used with browserify.</p> <h4>Example</h4> <p><code>browserify().transform(es6ify)</code></p> </div> <dl class="details"> <dt class="tag-source">Source:</dt> <dd class="tag-source"><ul class="dummy"> <li> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js">index.js</a> <span>, </span> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js#L99">lineno 99</a> </li> </ul></dd> </dl> <h5>Returns:</h5> <div class="param-desc"> <p>function that returns a <code>TransformStream</code> when called with a <code>file</code></p> </div> <dl> <dt> Type </dt> <dd> <span class="param-type">function</span> </dd> </dl> </dd> <dt> <h4 class="name" id="es6ify::compileFile"><span class="type-signature"></span>es6ify::compileFile<span class="signature">(file, src)</span><span class="type-signature"> &rarr; {string}</span></h4> </dt> <dd> <div class="description"> <p>Compile function, exposed to be used from other libraries, not needed when using es6ify as a transform.</p> </div> <h5>Parameters:</h5> <table class="params"> <thead> <tr> <th>Name</th> <th>Type</th> <th class="last">Description</th> </tr> </thead> <tbody> <tr> <td class="name"><code>file</code></td> <td class="type"> <span class="param-type">string</span> </td> <td class="description last"><p>name of the file that is being compiled to ES5</p></td> </tr> <tr> <td class="name"><code>src</code></td> <td class="type"> <span class="param-type">string</span> </td> <td class="description last"><p>source of the file being compiled to ES5</p></td> </tr> </tbody> </table> <dl class="details"> <dt class="tag-source">Source:</dt> <dd class="tag-source"><ul class="dummy"> <li> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js">index.js</a> <span>, </span> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js#L20">lineno 20</a> </li> </ul></dd> </dl> <h5>Returns:</h5> <div class="param-desc"> <p>compiled source</p> </div> <dl> <dt> Type </dt> <dd> <span class="param-type">string</span> </dd> </dl> </dd> <dt> <h4 class="name" id="es6ify::configure"><span class="type-signature"></span>es6ify::configure<span class="signature">(<span class="optional">filePattern</span>)</span><span class="type-signature"> &rarr; {function}</span></h4> </dt> <dd> <div class="description"> <p>Configurable es6ify transform function that allows specifying the <code>filePattern</code> of files to be compiled.</p> </div> <h5>Parameters:</h5> <table class="params"> <thead> <tr> <th>Name</th> <th>Type</th> <th>Argument</th> <th class="last">Description</th> </tr> </thead> <tbody> <tr> <td class="name"><code>filePattern</code></td> <td class="type"> <span class="param-type">string</span> </td> <td class="attributes"> &lt;optional><br> </td> <td class="description last"><p>(default: `/.js$/) pattern of files that will be es6ified</p></td> </tr> </tbody> </table> <dl class="details"> <dt class="tag-source">Source:</dt> <dd class="tag-source"><ul class="dummy"> <li> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js">index.js</a> <span>, </span> <a href="https://github.com/thlorenz/es6ify/blob/master/index.js#L112">lineno 112</a> </li> </ul></dd> </dl> <h5>Returns:</h5> <div class="param-desc"> <p>function that returns a <code>TransformStream</code> when called with a <code>file</code></p> </div> <dl> <dt> Type </dt> <dd> <span class="param-type">function</span> </dd> </dl> </dd> </dl> </article> </section> </div>

generated with docme

</div> <!-- END docme generated API please keep comment here to allow auto update -->

Examples

es6ify.configure(filePattern : Regex)

The default file pattern includes all JavaScript files, but you may override it in order to only transform files coming from a certain directory, with a specific file name and/or extension, etc.

By configuring the regex to exclude ES5 files, you can optimize the performance of the transform. However transforming ES5 JavaScript will work since it is a subset of ES6.

browserify({ debug: true })
  .add(require('es6ify').runtime)
   // compile all .js files except the ones coming from node_modules
  .transform(require('es6ify').configure(/^(?!.*node_modules)+.+\.js$/))
  .require(require.resolve('./src/main.js'), { entry: true })
  .bundle()
  .pipe(fs.createWriteStream(bundlePath));

es6ify.traceurOverrides

Some features supported by traceur are still experimental: either nonstandard, proposed but not yet standardized, or just too slow to use for most code. Therefore Traceur disables them by default. They can be enabled by overriding these options.

For instance to support the async functions (async/await) feature you'd do the following.

var es6ify = require('es6ify');
es6ify.traceurOverrides = { asyncFunctions: true };
browserify({ debug: true })
  .add(es6ify.runtime)
  .require(require.resolve('./src/main.js'), { entry: true })
  .bundle()
  .pipe(fs.createWriteStream(bundlePath));

Caching

When es6ify is run on a development server to help generate the browserify bundle on the fly, it makes sense to only recompile ES6 files that changed. Therefore es6ify caches previously compiled files and just pulls them from there if no changes were made to the file.

Source Maps

es6ify instructs the traceur transpiler to generate source maps. It then inlines all original sources and adds the resulting source map base64 encoded to the bottom of the transformed content. This allows debugging the original ES6 source when using the debug flag with browserify.

If the debug flag is not set, these source maps will be removed by brows