Prevent updating user's password if the input was left empty? - node.js

Question

I'm struggling to prevent updating user's password in database if the password input was left empty.
Here is the route responsible for updating user data:
router.put('/update', passport.authenticate('jwt', {session: false}), (req, res) => {
let user = req.user;
user.firstname = req.body.firstname;
user.lastname = req.body.lastname;
user.username = req.body.username;
user.email = req.body.email;
user.password = req.body.password || null;
User.updateUser(user, (err) => {
if (err) {
res.json({
success: false,
message: 'User details couldn\'t be updated.'
});
} else {
res.json({
success: true,
message: 'User updated'
});
}
});
});
And here is the User model method which generates a hash of a password and saves the new data in the database:
module.exports.updateUser = function (user, callback) {
if (user.password) {
bcrypt.genSalt(10, (err, salt) => {
bcrypt.hash(user.password, salt, (err, hash) => {
if (err) throw err;
user.password = hash;
});
});
}
user.save(callback);
};
I check if the password value was given but I don't know how to keep the old encrypted password in the database if there is no new value given for the password. If user doesn't fill the password input, it is being saved as null, as expected though...
I hope there is an approach to achieve this, I just can't figure out at the moment as I'm a beginner.
Thank you in advance!

Answer 1

I guess that you are using Mongoose to communicate with the Database.
Change this Line of your code :
user.password = req.body.password || null;
with this :
if(req.body.password != null) {
user.password = req.body.password
}else{
/* find each user with a last name matching 'user.userame', selecting
/*the `password` field and returning the result in 'usr'
*/
User.find({'username' : user.username}, 'password', function (err, usr) {
if (err) return handleError(err);
user.password = usr.password;
})
}

Answer 2

Based on #Neil Lunn's suggestion about checking the documentation, I came up with a solution. I changed the updateUser method to this:
module.exports.updateUser = function (user, callback) {
if (user.password) {
bcrypt.genSalt(10, (err, salt) => {
bcrypt.hash(user.password, salt, (err, hash) => {
if (err) throw err;
user.password = hash;
user.save(callback);
});
});
} else {
User.findById(user.id).update({
username: user.username,
email: user.email,
firstname: user.firstname,
lastname: user.lastname
}, callback);
}
};
If the password is present, then update everything as is, if no password provided, then update only the needed fields except the password.
Maybe this is not the best solution, but it works for now.
Thank you!