collect_asset_files

# File actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 914
        def collect_asset_files(*path)
          dir = path.first

          Dir[File.join(*path.compact)].collect do |file|
            file[-(file.size - dir.size - 1)..-1].sub(/\.\w+$/, '')
          end.sort
        end