Rake task to rebuild all JS/CSS assets with Compass/Jammit, including workaround for the bugs within.

assets.rake

namespace :assets do
  task :rebuild do
    # Config the base names of all the jammit CSS packages you have defined
    # in assets.yml. Could probably parse assets.yml to get this if
    # we wanted to.
    packages = ['common']

    # This is because on OS X, you have to put an explicit empty string to the
    # required extension argument with the -i parameter, but on Linux you
    # do not.
    in_place_option = "-i"
    if `uname` =~ /darwin/i
      in_place_option = '-i ""'
    end

    Dir.chdir(RAILS_ROOT) do
      sh("compass compile --force")

      # This is a workaround for this jammit bug:
      #   https://github.com/documentcloud/jammit/issues/#issue/120
      #
      sh("sed #{in_place_option} -e \"s/^@charset.*$//g\" public/stylesheets/*.css")

      sh("jammit --force")
    
      # This is a workaround for this YuiCompressor bug:
      #   http://yuilibrary.com/projects/yuicompressor/ticket/2528053
      #
      Dir.chdir("public/assets") do
        packages.each do |package|
          Dir.glob("#{package}*.css").each do |file|
            sh("sed #{in_place_option} -e \"s/@media \\([^[:space:]]*\\) and(/@media \\1 and (/g\" #{file}")
            sh("gzip --best --stdout #{file} > #{file}.gz")
          end
        end
      end
    end
  end
end