my rails helper for webpack dev server, and compiled into public

anonymous-gist.rb

  def include_js(file)
    @_js_includes ||= {}
    @_js_includes[file] ||= begin
      manifest_path = Rails.root.join('public', 'assets', 'manifest.json')

      if File.exist?(manifest_path)
        manifest = JSON.parse(File.read(manifest_path))
        path = "/assets/#{manifest[file]}"
      else
        path = "http://127.0.0.1:8080/#{file}"
      end

      %(<script type="text/javascript" src="#{path}"></script>).html_safe
    end