Mongoose toJSON

test.js

var mongoose = require('mongoose')
  , Schema = mongoose.Schema

mongoose.connect('localhost', 'testing_tojsonWithVirtuals');

var PersonSchema = new Schema({
    name    : String
  , age     : Number
});

var StorySchema = new Schema({
    _creator : { type: Schema.ObjectId, ref: 'Person' }
  , title    : String
});

var Story  = mongoose.model('Story', StorySchema);
var Person = mongoose.model('Person', PersonSchema);

Story.prototype._toJSON = Story.prototype.toJSON;
Story.prototype.toJSON = function() {
  var res = this._toJSON();
  res.was_in_to_json = true;
  return res;
}

Person.prototype._toJSON = Person.prototype.toJSON;
Person.prototype.toJSON = function() {
  var res = this._toJSON();
  res.was_in_to_json = true;
  return res;
}

mongoose.connection.on('open', function () {
  Person.create({ name: 'Jerem', age: 42 }, function (err, person) {
    if (err) return console.error(err.stack||err);

    Story.create({ title: 'Test', _creator: person }, function (err, story) {
      if (err) return console.error(err.stack||err);

      Story.findById(story).populate('_creator').run(function (err, doc) {
        if (err) return console.error(err.stack||err);
        console.error(doc.toJSON());

        mongoose.connection.db.dropDatabase(function () {
          mongoose.connection.close();
        });
      });
    });
  });
});