Error: Illegal arguments: string, undefined - string

Question

Matching User while logging in
const LocalStrategy = require('passport-local').Strategy;
const mongoose = require('mongoose');
const bcrypt = require('bcryptjs');
// Load User Model
const User = require('../models/User');
module.exports = function(passport) {
passport.use(
new LocalStrategy({ username: 'username' }, (username,
password, done) => {
// Match User
User.findOne({ username: username })
.then(user => {
if (!user) {
return done(null, false, { message: 'username is
not registered' });
}
// Match Password
bcrypt.compare(password, user.hashedPassword, (err,
isMatch) => {
if (err) throw err;
if (isMatch) {
return done(null, user);
} else {
return done(null, false, { message:
'Password incorrect' });
}
});
})
.catch(err => console.error(err))
})
);
passport.serializeUser((user, done) => {
done(null, user.id);
});
passport.deserializeUser((id, done) => {
User.findById(id, (err, user) => {
done(err, user);
});
});
}
Validation pass while registering user
User.findOne({ username: username })
.then(async user => {
if (user) {
//User exists
errors.push({ msg: "username has already taken" });
res.render('register', {
errors,
username,
password
});
} else {
const salt = await bcrypt.genSalt(10);
const hashedPassword = await bcrypt.hash(password,
salt);
const newUser = new User({
username: username,
password: hashedPassword,
});
newUser.save()
.then(user => {
// res.status(201).json(user);
req.flash('success_msg', 'You are now
registered')
res.redirect('/users/login');
})
.catch(err => console.log(err));
}
})
.catch(err => {
console.log(err);
})
}
../models/User
// Importing modules
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const UserSchema = new mongoose.Schema({
username: {
type: String,
lowercase: true,
unique: true,
// required: [true, "can't be blank"],
match: [/^[a-zA-Z0-9]+$/, 'is invalid'],
index: true
},
password: {
type: String,
required: true
},
Date: {
type: Date,
default: Date.now
}
}, { timestamps: true });
// export userschema
module.exports = mongoose.model('User', UserSchema);
why is it showing the error "Error: Illegal arguments: string, undefined". The same error was throwing when saving the password as hash in DB and now the same error throwing while comparing the hashed password. I checked the documentation, the format is the same but I think there is a syntactical error.

Answer 1

In the definition of the User data type, only the fields username and password exist. There is no field hashedPassword. However, you're trying to access this field in the line saying bcrypt.compare(password, user.hashedPassword ....
You're stroring the hased password in the password field here:
const newUser = new User({
username: username,
password: hashedPassword,
});
So later, you also need to read it from the password field:
bcrypt.compare(password, user.password ...