Fast client-side asset builder


A fast, reliable asset pipeline, supporting constant-time rebuilds and compact build definitions. Comparable to the Rails asset pipeline in scope, though it runs on Node and is backend-agnostic. For background and architecture, see the introductory blog post.

For the command line interface, see broccoli-cli.

This is 0.x beta software.

Windows support appears to still be spotty. Reports (on GitHub or IRC) about specific failures are much appreciated -- we love collecting stack traces!

npm install --save-dev broccoli
npm install --global broccoli-cli

Check out broccoli-sample-app.

A Brocfile.js file in the project root contains the build specification. It should export a tree which may simply be the directory path (as a string). To build more advanced output trees you may want to use some of the plugins listed below.

The following would export the app/ subdirectory as a tree:

module.exports = 'app'

Alternatively, the following would export the app/ subdirectory as appkit/:

var pickFiles = require('broccoli-static-compiler')
module.exports = pickFiles('app', {
  srcDir: '/',
  destDir: 'appkit'

You can find plugins on or under the broccoli-plugin-keyword on npm.

Shared code for writing plugins.

Broccoli defines a single plugin API: a tree. A tree object represents a tree (directory hierarchy) of files that can be regenerated on each build.

By convention, plugins will export a function that takes one or more input trees, and returns an output tree object.

A tree object must supply two methods that will be called by Broccoli:

The .read method must return a path or a promise for a path, containing the tree contents.

It receives a readTree function argument from Broccoli. If .read needs to read other trees, it must not call directly. Instead, it must call readTree(otherTree), which returns a promise for the path containing otherTree's contents. It must not call readTree again until the promise has resolved; that is, it cannot call readTree on multiple trees in parallel.

Broccoli will call the .read method repeatedly to rebuild the tree, but at most once per rebuild; that is, if a tree is used multiple times in a build definition, Broccoli will reuse the path returned instead of calling .read again.

The .read method is responsible for creating a new temporary directory to store the tree contents in. Subsequent invocations of .read should remove temporary directories created in previous invocations.

For every tree whose .read method was called one or more times, the .cleanup method will be called exactly once. No further .read calls will follow .cleanup. The .cleanup method should remove all temporary directories created by .read.

When it is known which file caused a given error, plugin authors can make errors easier to track down by setting the .file property on the generated error.

This .file property is used by both the console logging, and the server middleware to display more helpful error messages.

As of 0.11 Broccoli prints a log of any trees that took a significant amount of the total build time to assist in finding which trees are consuming the largest build times.

To determine the name to be printed Broccoli will first look for a .description property on the plugin instance then fall back to using the plugin constructor's name.

  • Do not run broccoli serve on a production server. While this is theoretically safe, it exposes a needlessly large amount of attack surface just for serving static assets. Instead, use broccoli build to precompile your assets, and serve the static files from a web server of your choice.
  • IRC: #broccolijs on Freenode. Ask your question and stick around for a few hours. Someone will see your message eventually.
  • Twitter: mention @jo_liss with your question
  • GitHub: Open an issue on a specific plugin repository, or on this repository for general questions.

Broccoli was originally written by Jo Liss and is licensed under the MIT license.

The Broccoli logo was created by Samantha Penner (Miric) and is licensed under CC0 1.0.