Is data returned from Mongoose immutable?

Question

I want to add to the return data from a mongoose query:

User.findById(userId, function(err, data) {
  if (!err) {
    data.newvar = \'Hello, world\';
  }
});         


        

Answer 1

As it turns out, Mongoose documents are their own special class and not standard Javascript objects. In order to get a javascript option that can be extended, you must use the toObject() method.