无法使用MongoDB在node.js中导出用户数据

Question

我似乎无法找到一种方法来导出我从数据库中获取的用户数据。当我在另一个文件中需要它时，我得到未定义的值或空对象。请帮助我想要的是导出用户信息，以便我可以在另一个文件中使用它。

我的auth.js文件：

// Modules
var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var url = 'mongodb://localhost:27017/affinity';
window.$ = window.jQuery = require('jquery');

$(document).ready(function () {

   // Look through db for user
   // Flters through the db to find the user and their password to authenticate them in.
   userInfo = function (db, callback) {
      var username = $('#username').val();
      var password = $('#password').val();
      var users = db.collection('users');

      // Searches through each user in the db to find one which meets conitions.
      var cursor = users.find({
         "username": username
      }, {"limit": 1} ).each(function (err, doc) {
         if (doc != null) {
            if (doc.password === password) {
               module.exports.user_data = doc;
               window.location.replace(__dirname + '/assets/views/main.html');
            } else {
               $("#error-hint").css(
                  'visibility', 'visible'
               );
            }
         } else {
            // Skip user if it isn't matching
         }
      });
   }

   // Connects to database.
   // Inserts all user data to the database.
   MongoClient.connect(url, function (err, db) {
      if (err) {
         console.log('Couldn\'t connect to the mongoDB server. \nERROR: ' + err);
      } else {
         var collection = db.collection('users');

         // When login button run authUser function
         $('#auth-btn').click(function () {
            userInfo(db, function () {
               db.close();
            });
         });
      }
   });

});

我的app.js文件：

// Modules
var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var url = 'mongodb://localhost:27017/affinity';
var exported = require("/Users/mac/Desktop/projects/Affinity/assets/scripts/auth.js");
window.$ = window.jQuery = require('jquery');

$(document).ready(function () {

   var userInfo = exported;
   console.log(userInfo);

   MongoClient.connect(url, function (err, db) {
      if (err) {
         console.log("Wasn't able to connect to mongoDB server. \n" + url);
      } else {
         console.log("Connection established to " + url);
         db.close();
      }
   });

});

提前谢谢！