Guard::CoffeeScript

Guard::CoffeeScript compiles or validates your CoffeeScripts automatically when files are modified. If you're looking for a CoffeeScript merge tool, please checkout Guard::CoffeeDripper.

Tested on MRI Ruby 1.9.3, 2.0.0, 2.1.0 and the latest versions of JRuby & Rubinius.

If you have any questions please join us on our Google group or on #guard (irc.freenode.net).

The simplest way to install Guard is to use Bundler. Please make sure to have Guard installed.

Add Guard::Coffeescript to your Gemfile:

group :development do
  gem 'guard-coffeescript'
end

Add the default Guard::Coffeescript template to your Guardfile by running:

$ guard init coffeescript

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.

Guard::CoffeeScript uses Ruby CoffeeScript to compile the CoffeeScripts, that in turn uses ExecJS to pick the best runtime to evaluate the JavaScript.

• With CRuby you want to use a V8 JavaScript Engine or Mozilla SpiderMonkey.
• With JRuby you want to use the Mozilla Rhino.
• On Mac OS X you want to use Apple JavaScriptCore.
• On Linux or as a node.js developer you want to use Node.js (V8).
• On Windows you want to use Microsoft Windows Script Host.

The following sections gives you a short overview of the available JavaScript runtimes and how to install it.

You can install node.js and use its V8 engine. On OS X you may want to install it with Homebrew, on Linux with your package manager and on Windows you have to download and install the executable.

To use the V8 JavaScript Engine, simple add therubyracer to your Gemfile. The Ruby Racer acts as a bridge between Ruby and the V8 engine, that will be automatically installed by the Ruby Racer.

group :development do
  gem 'therubyracer'
end

Another alternative is Mustang, a Ruby proxy library for the awesome Google V8 JavaScript engine. Just add mustang to your Gemfile:

group :development do
  gem 'mustang'
end

To use Mozilla SpiderMonkey, simple add johnson to your Gemfile. Johnson embeds the Mozilla SpiderMonkey JavaScript runtime as a C extension.

group :development do
  gem 'johnson'
end

If you're using JRuby, you can embed the Mozilla Rhino runtime by adding therubyrhino to your Gemfile:

group :development do
  gem 'therubyrhino'
end

JavaScriptCore is Safari's Nitro JavaScript Engine and only usable on Mac OS X. You don't have to install anything, because JavaScriptCore is already packaged with Mac OS X.

Microsoft Windows Script Host is available on any Microsoft Windows operating systems.

Please read the Guard usage documentation.

Guard::CoffeeScript can be adapted to all kind of projects. Please read the Guard documentation for more information about the Guardfile DSL.

In a Ruby project you want to configure your input and output directories.

guard 'coffeescript', :input => 'coffeescripts', :output => 'javascripts'

If your output directory is the same as the input directory, you can simply skip it:

guard 'coffeescript', :input => 'javascripts'

With the introduction of the asset pipeline in Rails 3.1 there is no need to compile your CoffeeScripts with this Guard.

However, if you would still like to have feedback on the validation of your CoffeeScripts (preferably with a Growl notification) directly after you save a change, then you can still use this Guard and simply skip generation of the output file:

guard 'coffeescript', :input => 'app/assets/javascripts', :noop => true

This give you a faster compilation feedback compared to making a subsequent request to your Rails application. If you just want to be notified when an error occurs you can hide the success compilation message:

guard 'coffeescript', :input => 'app/assets/javascripts', :noop => true, :hide_success => true

Without the asset pipeline you just define an input and output directory like within a normal Ruby project:

guard 'coffeescript', :input => 'app/coffeescripts', :output => 'public/javascripts'

There following options can be passed to Guard::CoffeeScript:

:input => 'coffeescripts'           # Relative path to the input directory.
                                    # Files will be added that match a suffix
                                    # of /(.+\.(coffee|coffee\.md|litcoffee))
                                    # default: nil

:output => 'javascripts'            # Relative path to the output directory.
                                    # default: the path given with the :input option

:noop => true                       # No operation: do not write an output file.
                                    # default: false

:bare => true                       # Compile without the top-level function wrapper.
                                    # Provide either a boolean value or an Array of
                                    # filenames.
                                    # default: false

:shallow => true                    # Do not create nested output directories.
                                    # default: false

:source_map => true                 # Do create the source map file.
                                    # default: false

:source_root => 'coffeescripts'     # Root path for coffeescript sources.
                                    # Used in source map to determine root URL for
                                    # all sources
                                    # default: nil (using the `:input` directory)

:hide_success => true               # Disable successful compilation messages.
                                    # default: false

:all_on_start => true               # Regenerate all files on startup
                                    # default: false

:error_to_js => true                # Print the Coffeescript error message directly in
                                    # the JavaScript file
                                    # default: false

The :source_map option needs at least CoffeeScript version 1.6.1.

In addition to the standard configuration, this Guard has a short notation for configure projects with a single input and output directory. This notation creates a watcher from the :input parameter that matches all CoffeeScript files under the given directory and you don't have to specify a watch regular expression.

guard 'coffeescript', :input => 'javascripts'

The :bare option can take a boolean value that indicates if all scripts should be compiled without the top-level function wrapper.

:bare => true

But you can also pass an Array of filenames that should be compiled without the top-level function wrapper. The path of the file to compile is ignored, so the list of filenames should not contain any path information:

:bare => %w{ a.coffee b.coffee }

In the above example, all a.coffee and b.coffee files will be compiled with option :bare => true and all other files with option :bare => false.

The Guard detects by default nested directories and creates these within the output directory. The detection is based on the match of the watch regular expression:

A file

/app/coffeescripts/ui/buttons/toggle_button.coffee

that has been detected by the watch

watch(%r{^app/coffeescripts/(.+\.coffee)$})

with an output directory of

:output => 'public/javascripts/compiled'

will be compiled to

public/javascripts/compiled/ui/buttons/toggle_button.js

Note the parenthesis around the .+\.coffee. This enables Guard::CoffeeScript to place the full path that was matched inside the parenthesis into the proper output directory.

This behavior can be switched off by passing the option :shallow => true to the Guard, so that all JavaScripts will be compiled directly to the output directory.

The Guard short notation

guard 'coffeescript', :input => 'app/coffeescripts', :output => 'public/javascripts/compiled'

will be internally converted into the standard notation by adding /(.+\.coffee) to the input option string and create a Watcher that is equivalent to:

guard 'coffeescript', :output => 'public/javascripts/compiled' do
  watch(%r{^app/coffeescripts/(.+\.coffee)$})
end

To add a second source directory that will be compiled to the same output directory, just add another watcher:

guard 'coffeescript', :input => 'app/coffeescripts', :output => 'public/javascripts/compiled' do
  watch(%r{lib/coffeescripts/(.+\.coffee)})
end

which is equivalent to:

guard 'coffeescript', :output => 'public/javascripts/compiled' do
  watch(%r{app/coffeescripts/(.+\.coffee)})
  watch(%r{lib/coffeescripts/(.+\.coffee)})
end

You can report issues and feature requests to GitHub Issues. Try to figure out where the issue belongs to: Is it an issue with Guard itself or with a Guard::Cucumber? Please don't ask question in the issue tracker, instead join us in our Google group or on #guard (irc.freenode.net).

When you file an issue, please try to follow to these simple rules if applicable:

• Make sure you run Guard with bundle exec first.
• Add debug information to the issue by running Guard with the --debug option.
• Add your Guardfile and Gemfile to the issue.
• Make sure that the issue is reproducible with your description.

• Documentation hosted at RubyDoc.
• Source hosted at GitHub.

Pull requests are very welcome! Please try to follow these simple rules if applicable:

• Please create a topic branch for every separate change you make.
• Make sure your patches are well tested.
• Update the Yard documentation.
• Update the README.
• Update the CHANGELOG for noteworthy changes.
• Please do not change the version number.

For questions please join us in our Google group or on #guard (irc.freenode.net).

Developed by Michael Kessler, sponsored by FlinkFinger.

If you like Guard::CoffeeScript, you can watch the repository at GitHub and follow @netzpirat on Twitter for project updates.

See the GitHub list of contributors.

• Jeremy Ashkenas for CoffeeScript, that little language that compiles into JavaScript and makes me enjoy the frontend.
• The Guard Team for giving us such a nice piece of software that is so easy to extend, one has to make a plugin for it!
• All the authors of the numerous Guards available for making the Guard ecosystem so much growing and comprehensive.

(The MIT License)

Copyright (c) 2010-2013 Michael Kessler

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.