delete property doesn't work in node.js

Question

I wonder why I can't delete password object, my console result shows the password is still there, I wonder why.

User.comparePassword(password, user.password , (err, result) => {
  if (result === true){
    User.getUserById(user._id, (err, userResult) => {
      delete userResult.password

      const secret = config.secret;
      const token = jwt.encode(userResult, secret);

      console.log(userResult)

      res.json({success: true, msg: {token}});
    });
  } else {
    res.json({success: false, msg: 'Error, Incorrect password!'});
  }
}

please check this, https://stackoverflow.com/questions/33239464/javascript-delete-object-property-not-working — Raghav Garg, Aug 27 '17 at 09:41
please try this, `let userObj = Object.assign({}, userResult)` then delete the property `password` of object `userObj`, like: `delete userObj.password` — Raghav Garg, Aug 27 '17 at 09:53
if that doesn't work, can you move `console.log(userResult)` right below `delete userResult.password`? just to be sure that `jwt.encode` doesn't mutate `userResult` somehow. — Federkun, Aug 27 '17 at 10:13

score 9 · Accepted Answer · answered Aug 27 '17 at 11:26

There are multiple solutions to your problem. You cannot delete property from Mongoose query, because you get some Mongoose wrapper. In order to manipulate object you need to transform it to JSON object. So there are three possible way that I can remember to do that:

1) Call toObject method mongoose object (userResult) like this:

 let user = userResult.toObject();
 delete user['password'];

2) Redefine toJson method of User model:

UserSchema.set('toJSON', {
        transform: function(doc, ret, options) {
            delete ret.password;
            return ret;
        }
});

3) Query can return object without specified field, so that you don't need to delete anything:

 User.findById(user._id, {password: 0}, function (err, userResult) {
   ...
 }

Wow thanks so much didn't know it has anything to do with mongoose. — Jenny Mok, Aug 27 '17 at 11:43

delete property doesn't work in node.js

1 Answers1