non_digest_assets.rb

class NonDigestAssets
  include Rake::DSL

  FILES = ["external/app.js"]

  def generate
    assets_files.map do |file|
      non_digested = file.gsub /(\-[a-z0-9]{32})/, ""

      next unless FILES.all? {|s| non_digested =~ /#{s}/}
      copy(file, non_digested)
    end

  end

  def assets_files
    Rake::FileList.new("public/assets/**/*") do |list|
      list.exclude do |file|
        file !~ /\-[a-z0-9]{32}\.[a-z]{2,4}/
      end
    end
  end

  def copy(from, to)
    sh "cp #{from} #{to}"
  end
end