Mongoose-q一直返回null

Question

Node noob并且第一次在这里问一个问题，所以我希望我能做到这一点..

我使用https://github.com/jkvoorhis/userAuth作为格式化代码的基础，用Mongoose方法替换Orchestra。

每当我向/ register发送POST请求时，我在节点窗口中的响应都是：

null
username already exists
COULD NOT REGISTER
POST /register 302
GET /failed 304

当MongoDB中的文档存在时，为什么它会一直返回null？ User.findOneQ({"username": username})有什么问题吗？我弄乱了mongoose = require('mongoose-q')()吗？非常感谢你。

App.js：

var express             = require('express'),
    http                  = require('http'),
    path                  = require('path'),
    mongoose            = require('mongoose'),
    passport            = require('passport'),
    LocalStrategy   = require('passport-local'),
    morgan              = require('morgan'),
    bodyParser        = require('body-parser'),
    methodOverride  = require('method-override'),
    cookieParser    = require('cookie-parser'),
    cookieSession   = require('cookie-session'),
    session             = require('express-session'),
    redis               = require('redis'),
    RedisStore        = require('connect-redis')(session);

var Config = require('./config/config.js');
var app = module.exports = express();
var auth = require('./server/controllers/auth');


//mongo
var mongoUri = process.env.MONGOLAB_URI ||
  process.env.MONGOHQ_URL || Config.mongo.address

mongoose.connect(mongoUri);

app.set('views', __dirname + '/client/views');
app.set('view engine', 'jade');
app.use(morgan('dev'));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
app.use(methodOverride());
app.use(express.static(path.join(__dirname, 'client')));

//redis session cookie
app.use(cookieParser());
app.use(session({
  store: new RedisStore({
    host: Config.redis.host,
    port: Config.redis.port,
    pass: Config.redis.pass
  }),
  secret: '1234567890QWERTY'
}));

// Passport session setup.
passport.serializeUser(function(user, done) {
  console.log("serializing " + user.username);
  done(null, user);
});

passport.deserializeUser(function(obj, done) {
  console.log("deserializing " + obj);
  done(null, obj);
});

// Use the LocalStrategy within Passport to Register/"signup" users.
passport.use('local-register', new LocalStrategy(
  {passReqToCallback : true}, //allows us to pass back the request to the callback
  function(req, username, password, done) {
    auth.register(username, password)
    .then(function (user) {
      if (user) {
        console.log("REGISTERED: " + user.username);
        req.session.success = 'You are successfully registered and logged in ' + user.username + '!';
        done(null, user);
      }
      if (!user) {
        console.log("COULD NOT REGISTER");
        req.session.error = 'That username is already in use, please try a different one.'; //inform user could not log them in
        done(null, user);
      }
    })
    .fail(function (err){
      console.log(err.body);
    });
  }
));

// Simple route middleware to ensure user is authenticated.
function ensureAuthenticated(req, res, next) {
  if (req.isAuthenticated()) { return next(); }
  req.session.error = 'Please sign in!';
  res.redirect('/signin');
}

app.post('/register', passport.authenticate('local-register', {
  successRedirect: '/success',
  failureRedirect: '/failed'
  })
);

app.post('/login', function(req,res){
  var data = req.body;
  console.log(data.username + ' ' + data.password);
  res.send(data.username + ' ' + data.password);
});

app.post('/logout', function(req,res){
  res.send('logout page');
});

app.get('/users', function(req, res){
  res.send('hello world');
});

app.get('/success', function(req,res){
  res.send('it was a success!');
})

app.get('/failed', function(req,res){
  res.send('it faaailed!');
});

var port = Number(process.env.PORT || 8000);
app.listen(port, function() {
  console.log("Listening on " + port);
});

Auth.js：

var bcrypt = require('bcrypt-nodejs'),
    mongoose = require('mongoose-q')(),
    User = require('../models/UserSchema'),
    Q = require('q');

exports.register = function (username, password) {
  var deferred = Q.defer(); 
  var hash = bcrypt.hashSync(password, bcrypt.genSaltSync(8), null);
  var user = {
    "username": username,
    "password": hash
  };
  //check if username is already assigned in our database
  User.findOneQ({"username": username})
  .then(function (result){ //case in which user already exists in db
    // console.log('result' + result.body);
    console.log(result);
    console.log('username already exists');
    deferred.resolve(false); //username already exists
  })
  .fail(function (result) {//case in which user does not already exist in db
      console.log(result.body);
      if (result.body.message == 'The requested items could not be found.'){
        console.log('Username is free for use');

        user.saveQ()
        .then(function(){
            console.log('user saved!');
            deferred.resolve(user);
        })
        .fail(function (err) {
          console.log("PUT FAIL:" + err.body);
          deferred.reject(new Error(err.body));
        });
      } else {
        deferred.reject(new Error(result.body));
      }
  });

  return deferred.promise;
};

user.js的：

var mongoose = require('mongoose');

//user
var UserSchema = new mongoose.Schema({
    username:   { type: String },
    password:   { type: String }
}, {collection: 'User'});

module.exports = mongoose.model('User', UserSchema);