Hashing password before update a user in mongoose - node.js

Question

I create the user, hash his password and save on mongo. My problem begins when I try to update that user. For now, when I update the hash isn't generated, cause I really don't know how to do it.
The middleware to get the user that I'm talking about:
exports.userByID = function(req, res, next, id) {
User.findOne(
{
_id: id
},
function(err, user) {
if (err) {
return next(err);
} else {
req.user = user;
next();
}
}
);
};
The user controller, to update an user:
exports.update = async function(req, res, next) {
User.findByIdAndUpdate(req.user.id, req.body, function(err, user) {
if (err) {
return next(err);
} else {
res.json(user);
}
});
};
The pre 'save' on User's model:
UserSchema.pre("save", function(next) {
var user = this;
if (user.password) {
var md5 = crypto.createHash("md5");
user.password = md5.update(user.password).digest("hex");
console.log("Password após o save (hasheando):" + user.password);
}
next();
});
I'm using passport authentication ('local'). Already tried user.save() on the controller update:
user.save();
res.json(user);
But, without success.

Answer 1

This is may be because you are not storing the new_password in the mongo.
In update controller you have to do like this:
User.findByIdAndUpdate(req.user.id, req.body, function (err, user) {
if (err) {
return next(err);
} else {
user.password = req.body.new_password;
user.save(function (err, user) {
if (err) {
res.send("Error: ", err);
} else {
res.send("password updated successfully!");
}
})
}
});

Answer 2

Before saving the password just hash it and update it in DB. it will be something like below.
exports.update = async function(req, res, next) {
let { body} = req;
if(body['password']){
var md5 = crypto.createHash("md5");
body['password']= md5.update(body['password']).digest("hex");
}
let updateUser = await User.findByIdAndUpdate(req.user.id, body)
};