# File lib/action_view/helpers/asset_tag_helper.rb, line 238
      def javascript_include_tag(*sources)
        options = sources.extract_options!.stringify_keys
        cache   = options.delete("cache")

        if ActionController::Base.perform_caching && cache
          joined_javascript_name = (cache == true ? "all" : cache) + ".js"
          joined_javascript_path = File.join(JAVASCRIPTS_DIR, joined_javascript_name)

          write_asset_file_contents(joined_javascript_path, compute_javascript_paths(sources))
          javascript_src_tag(joined_javascript_name, options)
        else
          expand_javascript_sources(sources).collect { |source| javascript_src_tag(source, options) }.join("\n")
        end
      end