Rake file for executing guard to prepare your environment

prepare.rake

desc "compiles all coffeescripts and scss stylesheets in the project"
task :prepare => 'prepare:all'.to_sym

namespace :prepare do

  desc "compiles all coffeescripts in the project"
  task :coffeescript do
    run_guards "Guard::CoffeeScript"
  end

  desc "compiles all coffeescripts in the project"
  task :sass do
    run_guards "Guard::Sass"
  end

  desc "compiles all coffeescripts and scss stylesheets in the project"
  task :all do
    run_guards "Guard::CoffeeScript", "Guard::Sass"
  end

end

def run_guards *guards
  require 'guard'
  Guard.setup
  Guard::Dsl.evaluate_guardfile

  Guard::guards.reject! { |guard| !guards.include? guard.class.name }

  Guard::guards.each do |guard|
    guard.run_all if guards.include? guard.class.name
  end

end

Override task behaviour.

http://metaskills.net/2010/05/26/the-alias_method_chain-of-rake-override-rake-task/

Rake::TaskManager.class_eval do
def alias_task(fq_name)
new_name = "#{fq_name}:original"
@tasks[new_name] = @tasks.delete(fq_name)
end
end

def alias_task(fq_name)
Rake.application.alias_task(fq_name)
end

def override_task(_args, &block)
name, params, deps = Rake.application.resolve_args(args.dup)
fq_name = Rake.application.instance_variable_get(:@scope).dup.push(name).join(':')
alias_task(fq_name)
Rake::Task.define_task(_args, &block)
end

override_task :environment do
Rake::Task["prepare:all"].execute
Rake::Task["environment:original"].execute
end