How do I add temporary properties on a mongoose object just for response, which is not stored in database

Question

I would like to fill a couple of extra temporary properties with additional data and send back to the response

'use strict';  var mongoose = require('mongoose'); var express = require('express'); var app = express();  var TournamentSchema = new mongoose.Schema({     createdAt: { type: Date, default: Date.now },     deadlineAt: { type: Date } });  var Tournament = mongoose.model('Tournament', TournamentSchema);  app.get('/', function(req, res) {     var tournament = new Tournament();      // Adding properties like this 'on-the-fly' doesnt seem to work     // How can I do this ?     tournament['friends'] = ['Friend1, Friend2'];     tournament.state = 'NOOB';     tournament.score = 5;     console.log(tournament);     res.send(tournament); });  var server = app.listen(3000, function() {     console.log('Listening on port %d', server.address().port); }); 

But the properties wont get added on the Tournament object and therefor not in the response.

Answer 1

Found the answer here: Unable to add properties to js object

I cant add properties on a Mongoose object, I have to convert it to plain JSON-object using the .toJSON() or .toObject() methods.

EDIT: And like @Zlatko mentions, you can also finalize your queries using the .lean() method.

mongooseModel.find().lean().exec() 

... which also produces native js objects.