watch.rb

# -- coding: utf-8

require "grill"

Grill.implant <<-G
source "https://rubygems.org"

gem "sprockets"
gem "fssm"

gem "sass"
gem "coffee-script"
gem "pry"
G


def start(root)
  pid = Process.fork do
    env = Sprockets::Environment.new(root)
    generated = []
    FSSM.monitor(root, "**/*", :directries => false) do
      delete do |_, file|
        path = File.join(root, file)
      end

      [:update, :create].each do |event|
        send(event) do |_, file|
          path = File.join(root, file)
          if path == File.expand_path(".", __FILE__)
            puts "Going to restart the server.."
            Process.kill(:INT, $$)
            next
          end

          if generated.include?(path)
            puts "Ignore: #{path} is generated file"
            next
          end

          dir = File.dirname(path)
          env.append_path(dir) unless env.paths.include?(dir)
          begin
            asset = env.find_asset(File.basename(file))
            ext = env.extension_for_mime_type(asset.content_type)
            dest = "#{path.gsub(%r!/(.*?)\..*$!, "/\\1")}#{ext}"
            File.open(dest, "w") do |f|
              f.write asset.to_s
            end
            generated << dest
            generated.uniq!
            puts "Generate: #{path} -> #{dest}"
          rescue => e
            p e
          end
        end
      end
    end
  end
end

puts "Start watcher"
root = File.expand_path(ARGV.first || File.dirname(__FILE__))
pid = start(root)
Process.waitpid pid
Bundler.with_clean_env do
  exec(ENV, "ruby", *[$0, ARGV].flatten)
end