Mongoose schema methods and “this” updating properties - NodeJS

Question

In my usersSchema I want to set a hashed password to my hash field. The schema looks like this:

// models/user-model.js

const usersSchema = new Schema({
  name: {
    type: String,
    required: true
  },
  email: {
    type: String,
    unique: true,
    required: true
  },
  hash: String,
  salt: String
}, { timestamps: true });

usersSchema.methods.setPassword = (password) => {
  this.salt = crypto.randomBytes(16).toString('hex');
  this.hash = crypto.pbkdf2Sync(password, this.salt, 1000, 64).toString('hex');
};

In my route, I am trying to set a new user with a name, email, and password. Here's the route:

// routes/users.js

router.get('/setup', (req, res) => {
  const user = new User();

  user.name = 'Jacob';
  user.email = 'jacob@gmail.com';

  user.setPassword('password');

  user.save()
    .then((user) => {
      const token = user.generateJwt();
      res.json({ yourToken: token });
    })
    .catch((err) => {
      res.json(err);
    });
});

When I console.log(user) from the route, it gives me the following: { name: 'Jacob', email: 'jacob@gmail.com' }

I know that the setPassword method works as far as creating proper hashes. It does not, however, save those hashes to the user object. How do I apply setPassword to the user object that calls it so that it can set the salt and hash properties?

Answer 1

By using the fat arrow notation, you're changing what this is referring to in setPassword , so it's not pointing to the user document anymore.

Try using a regular function declaration:

usersSchema.methods.setPassword = function(password) {
  this.salt = crypto.randomBytes(16).toString('hex');
  this.hash = crypto.pbkdf2Sync(password, this.salt, 1000, 64).toString('hex');
};