猫鼬模式无法读取未定义的属性“密码”

我按照教程尝试了护照本地认证。一切似乎都很好，但是使用Postman发出请求时出现此错误：

[nodemon] 1.18.11
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node server.js`
body-parser deprecated bodyParser: use individual json/urlencoded middlewares server.js:17:10
(node:6336) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.
Started listening on PORT: 8080
events.js:167
      throw er; // Unhandled 'error' event
      ^

    TypeError: Cannot read property 'password' of undefined
        at model.userSchema.methods.validPassword.password [as validPassword] (F:\Web Projects\LocalAuth\userModel.js:20:50)
        at F:\Web Projects\LocalAuth\passport.js:34:21
        at F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFel.js:4672:16
        at F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFry.js:4184:12
        at process.nextTick (F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFry.js:2741:28)
        at process._tickCallback (internal/process/next_tick.js:61:11)
    Emitted 'error' event at:
        at F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFel.js:4674:13
        at F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFry.js:4184:12
        at process.nextTick (F:\Web Projects\LT1Kqob5UDEML61gCyjnAcfMXgkdP3wGcgGdBcFry.js:2741:28)
        at process._tickCallback (internal/process/next_tick.js:61:11)
    [nodemon] app crashed - waiting for file changes before starting...

这是我的用户架构：

const mongoose = require('mongoose');
const bcrypt = require('bcrypt-nodejs');
const Config = require ('./config');


mongoose.connect (Config.dbUrl);

let userSchema = new mongoose.Schema({
  local : {
    email: String,
    password: String,
  },
});

userSchema.methods.generateHash = password => {
  return bcrypt.hashSync(password, bcrypt.genSaltSync(8), null);
};

userSchema.methods.validPassword = password => {
  return bcrypt.compareSync(password, this.local.password);
};

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

这是我的server.js文件：

const express = require ('express');
const session = require ('express-session');
const mongoose = require ('mongoose');
const bodyParser = require ('body-parser');
const cookieParser = require ('cookie-parser');
const morgan = require ('morgan');
const flash = require ('connect-flash');
const passport = require ('passport');

const PassHandler = require('./passport');

const app = express ();
const port = process.env.PORT || 8080;


app.use (morgan ('dev'));
app.use (bodyParser ({extended: false}));
app.use (cookieParser ());

app.use (
  session ({secret: 'borkar.amol', saveUninitialized: true, resave: true})
);

//Initialize Passport.js
app.use (passport.initialize ());
app.use (passport.session ());
app.use (flash ());

//Global Vars for flash messages
app.use((req, res, next) => {
  res.locals.successMessage = req.flash('successMessage');
  res.locals.errorMessage = req.flash('errorMessage');
  res.locals.error = req.flash('error');
  next();
});

PassHandler(passport);

//Middleware to check if the user is logged in.
const isLoggedIn = (req, res, next) => {
  if(req.isAuthenticated()) {
    return next();
  }

  res.status(400).json({ message: 'You are not authenticated to acces this route.' });
}

app.get('/', (req, res) => {
  res.json({ message: 'Local Auth API v0.1.0'});
});

app.post('/signup', passport.authenticate('local-signup', {
  successRedirect: '/user',
  failureRedirect: '/signup',
  failureFlash: true,
}));

app.post('/login', passport.authenticate('local-login', {
  successRedirect: '/user',
  failureRedirect: '/',
  failureFlash: true,
}));

app.get('/user', isLoggedIn, (req, res) => {
  res.json({ user: req.user, message: "User is logged in."});
});

app.listen (port, () => {
  console.log (`Started listening on PORT: ${port}`);
});

这是我正在使用的Passport策略：

  passport.use (
    'local-login',
    new LocalStrategy (
      {
        usernameField: 'email',
        passwordField: 'password',
        passReqToCallback: true,
      },
      function (req, email, password, done) {
        User.findOne ({'local.email': email}, function (err, user) {
          if (err) return done (err);

          if (!user)
            return done (
              null,
              {message: 'User not found.'},
              req.flash ('errorMessage', 'No user found.')
            );
          if (!user.validPassword (password))
            return done (
              null,
              {message: 'Invalid email or password.'},
              req.flash ('errorMessage', 'Oops! Wrong password.')
            );

          // all is well, return successful user
          return done (null, user);
        });
      }
    )
  );

老实说，我不知道出了什么问题。请帮忙。

**更新：**注册路线和注册策略运行正常。只有/login路线给问题了。