安装directives.module.js

mkdir -p  app/assets/javascripts/directives
touch  app/assets/javascripts/directives/directives.module.js

//  app/assets/javascripts/directives.module.js

(function () {
    'use strict';

    angular.module('app.directives', []);

//   angular
//        .module('app.directives');
//        .factory('testService', function(){
//            return {
//                ping: function(){ return 'pong'; }
//            };
//        });

})();