def index
      validate_arguments!

      plugins = ::Heroku::Plugin.list

      if plugins.length > 0
        styled_header("Installed Plugins")
        styled_array(plugins)
      end
      ::Heroku::JSPlugin.list
    end
def index
      validate_arguments!

      plugins = ::Heroku::Plugin.list

      if plugins.length > 0
        styled_header("Installed Plugins")
        styled_array(plugins)
      end
      ::Heroku::JSPlugin.list
    end
plugins

 list installed plugins

Example:

 $ heroku plugins
 === Installed Plugins
 heroku-production-check@0.2.0