Rakefile for js project

Rakefile

require_relative 'config/commands'

root = File.expand_path('..', __FILE__)

ENV['PATH'] = "#{File.join(root, 'node_modules', '.bin')}:#{ENV['PATH']}"

scss_dir = File.join(root, 'app', 'css')
css_dir = File.join(root, 'build', 'css')
image_dir = File.join(root, 'app', 'images')
js_dir = File.join(root, 'app', 'js')
app_ts = File.join(root, 'app', 'js', 'app.ts')
app_js = File.join(root, 'build', 'js', 'app.js')

compass_options = "--sass-dir #{scss_dir} --css-dir #{css_dir} --images-dir #{image_dir} --javascripts-dir #{js_dir}"
browserify_options = '-p [ tsify --noImplicitAny ] -t [envify --NODE_ENV production]'

desc 'Install'
task :install do
  sh 'npm install'
  sh 'bundle install'
end

task :build_folder do
  sh "mkdir -p #{File.join(root, 'build', 'js')}"
end

desc 'Server'
task :server => :build_folder do
  sh 'bundle exec rackup -o 0.0.0.0 -p 9292'
end

desc 'Cleanup build'
task :clean do
  sh "rm -fr #{File.join(root, 'build')}"
end

desc 'Build app'
task :build => [:clean, :build_folder] do
  sh "browserify #{app_ts} #{browserify_options} | uglifyjs -cm > #{app_js}"
  sh "compass compile #{compass_options} -s compressed"
end

desc 'Watch files and recompile on change'
task :watch do
  js_watch = "watchify -v -d #{app_ts} #{browserify_options} -o #{app_js}"
  css_watch = "compass watch #{compass_options}"

  js_pid = Process.spawn(js_watch)
  css_pid = Process.spawn(css_watch)

  at_exit do
    Process.kill('TERM', js_pid) if js_pid
    Process.kill('TERM', css_pid) if css_pid
  end

  Process.waitpid(js_pid)
end