testmodelfindtoObject.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.connect('localhost', 'testing_testmodelfindtoObject');
mongoose.connection.on('error', function () {
  console.error(arguments);
});

var schema = new Schema({
    name: String
});

var A = mongoose.model('A', schema);

mongoose.connection.on('open', function () {
  A.create({ name: '1' },  {name: '2' }, function (err) {
    if (err) return console.error(err.stack||err);

    A.find(function (err, docs) {
      if (err) console.error(err.stack||err);

      console.error(JSON.stringify(docs)); // [{"name":"1","_id":"4fca5e1c201c42e893000001"},{"name":"2","_id":"4fca5e1c201c42e893000002"}]

      var vanilla = docs.map(function(d){ return d.toObject() });
      vanilla[0].asdf= 23;
      console.error('vanilla', JSON.stringify(vanilla)); // [{"name":"1","_id":"4fca5e1c201c42e893000001","asdf":23},{"name":"2","_id":"4fca5e1c201c42e893000002"}]

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