Guard

Guard is a command line tool that easily handle events on files modifications.

Features

• FSEvent support on Mac OS X 10.5+ (without RubyCocoa!, rb-fsevent gem, >= 0.3.5 required).
• Inotify support on Linux (rb-inotify gem, >= 0.5.1 required).
• Polling on the other operating systems (help us to support more OS).
• Automatic & Super fast (when polling is not used) files modifications detection (even new files are detected).
• Growl notifications (growlnotify & growl gem required).
• Libnotify notifications (libnotify gem required).
• Tested on Ruby 1.8.6, 1.8.7 & 1.9.2.

Install

Install the gem:

$ gem install guard

Add it to your Gemfile (inside the test group):

gem 'guard'

Generate an empty Guardfile with:

$ guard init

Add the guards you need to your Guardfile (see the existing guards below).

On Mac OS X

Install the rb-fsevent gem for FSEvent support:

$ gem install rb-fsevent

Install the Growl gem if you want notification support:

$ gem install growl

And add it to you Gemfile:

gem 'growl'

On Linux

Install the rb-inotify gem for inotify support:

$ gem install rb-inotify

Install the Libnotify gem if you want notification support:

$ gem install libnotify

And add it to you Gemfile:

gem 'libnotify'

Usage

Just launch Guard inside your Ruby / Rails project with:

$ guard [start]

or if you use Bundler, to run the Guard executable specific to your bundle:

$ bundle exec guard

Command line options

Shell can be cleared after each change with:

$ guard --clear
$ guard -c # shortcut

Notifications (growl/libnotify) can be disabled with:

$ guard --notify false
$ guard -n false # shortcut

The guards to start can be specified by group (see the Guardfile DSL below) specifying the --group (or -g) option:

$ guard --group group_name another_group_name
$ guard -g group_name another_group_name # shortcut

Options list is available with:

$ guard help [TASK]

Signal handlers

Signal handlers are used to interact with Guard:

• Ctrl-C - Calls each guard's stop method, in the same order they are declared in the Guardfile, and then quits Guard itself.
• Ctrl-\ - Calls each guard's run_all method, in the same order they are declared in the Guardfile.
• Ctrl-Z - Calls each guard's reload method, in the same order they are declared in the Guardfile.

Available Guards

Available Guards list (on the wiki now)

Add a guard to your Guardfile

Add it to your Gemfile (inside the test group):

gem '<guard-name>'

Insert default guard's definition to your Guardfile by running this command:

$ guard init <guard-name>

You are good to go!

Guardfile DSL

The Guardfile DSL consists of just three simple methods: guard, watch & group.

Required:

• The guard method allows you to add a guard with an optional hash of options.
• The watch method allows you to define which files are supervised by this guard. An optional block can be added to overwrite the paths sent to the run_on_change guard method or to launch any arbitrary command.

Optional:

• The group method allows you to group several guards together. Groups to be run can be specified with the Guard DSL option --group (or -g). This comes in handy especially when you have a huge Guardfile and want to focus your development on a certain part.

Example:

group 'backend' do
  guard 'bundler' do
    watch('Gemfile')
  end

  guard 'rspec', :cli => '--color --format doc' do
    # Regexp watch patterns are matched with Regexp#match
    watch(%r{^spec/.+_spec\.rb})
    watch(%r{^lib/(.+)\.rb})         { |m| "spec/lib/#{m[1]}_spec.rb" }
    watch(%r{^spec/models/.+\.rb})   { ["spec/models", "spec/acceptance"] }
    watch(%r{^spec/.+\.rb})          { `say hello` }

    # String watch patterns are matched with simple '=='
    watch('spec/spec_helper.rb') { "spec" }
  end
end

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

  guard 'livereload' do
    watch(%r{^app/.+\.(erb|haml)})
  end
end

Create a new guard

Creating a new guard is very easy, just create a new gem (bundle gem if you use Bundler) with this basic structure:

lib/
  guard/
    guard-name/
      templates/
        Guardfile (needed for guard init <guard-name>)
    guard-name.rb

Guard::GuardName (in lib/guard/guard-name.rb) must inherit from Guard::Guard and should overwrite at least one of the five basic Guard::Guard instance methods. Example:

require 'guard'
require 'guard/guard'

module Guard
  class GuardName < Guard

    def initialize(watchers=[], options={})
      super
      # init stuff here, thx!
    end

    # =================
    # = Guard methods =
    # =================

    # If one of those methods raise an exception, the Guard::GuardName instance
    # will be removed from the active guards.

    # Called once when Guard starts
    # Please override initialize method to init stuff
    def start
      true
    end

    # Called on Ctrl-C signal (when Guard quits)
    def stop
      true
    end

    # Called on Ctrl-Z signal
    # This method should be mainly used for "reload" (really!) actions like reloading passenger/spork/bundler/...
    def reload
      true
    end

    # Called on Ctrl-/ signal
    # This method should be principally used for long action like running all specs/tests/...
    def run_all
      true
    end

    # Called on file(s) modifications
    def run_on_change(paths)
      true
    end

  end
end

Please take a look at the existing guards' source code (see the list above) for more concrete example.

Alternatively, a new guard can be added inline to a Guardfile with this basic structure:

require 'guard/guard'

module ::Guard
  class Example < ::Guard::Guard
    def run_all
      true
    end

    def run_on_change(paths)
      true
    end
  end
end

Guard Hooks and Callbacks

Guard provides a mechanism for you to hook into the execution of individual Guards. Checkout the Wiki page for more details.

Development

• Source hosted at GitHub.
• Report Issues/Questions/Feature requests on GitHub Issues.

Pull requests are very welcome! Make sure your patches are well tested. Please create a topic branch for every separate change you make.

Author

Thibaud Guillaume-Gentil