Ruby CoffeeScript

Ruby CoffeeScript is a bridge to the official CoffeeScript compiler.

CoffeeScript.compile File.read(“script.coffee”)

Installation

gem install coffee-script

Note: This compiler library has replaced the original CoffeeScript
compiler that was written in Ruby.

Dependencies

This library depends on the coffee-script-source gem which is
updated any time a new version of CoffeeScript is released. (The
coffee-script-source gem’s version number is synced with each
official CoffeeScript release.) This way you can build against
different versions of CoffeeScript by requiring the correct version of
the coffee-script-source gem.

In addition, you can use this library with unreleased versions of
CoffeeScript by setting the COFFEESCRIPT_SOURCE_PATH environment
variable:

export COFFEESCRIPT_SOURCE_PATH=/path/to/coffee-script/extras/coffee-script.js

JSON

The json library is also required but is not explicitly stated as a
gem dependency. If you’re on Ruby 1.8 you’ll need to install the
json or json_pure gem. On Ruby 1.9, json is included in the
standard library.

ExecJS

The ExecJS library is used to automatically choose the best JavaScript engine for your platform. Check out its README for a complete list of supported engines.