nestedvalidation.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var assert = require('assert')
mongoose.connect('localhost', 'testing_findone');

var schema = new Schema({
  name: { last: { type: String, required: true} }
});

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

mongoose.connection.on('open', function () {
  A.findOne({}, ['name'], function (err, doc) {
    if (err) console.error(err.stack||err);
    assert.equal(null, doc);
    console.error('all good');

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

will test it on my huge model with lots of usecases ...

nice!

This is my next issue, custom validation functions are still called on fields which are not selected.

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var assert = require('assert')
mongoose.connect('localhost', 'testing_findone');
var schema = new Schema({
  name: {
    type: String,
    required: true,
    validate: [function(str) {
        return str.length < 20;
    }, 'MaxLength']
  },
  nick: {
    type: String,
    required: true
  },
  soemthing: String
}, {strict: true});

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

mongoose.connection.on('open', function () {
  var a = new A({
    name: 'name',
    nick: 'nick'
  });
  a.save(function(err) {
    assert.equal(null, err);

    A.findOne({},['nick'], function (err, doc) {
      if (err) console.error(err.stack||err);
      console.log('"name" in doc should be false but it is - ', 'name' in doc);

      doc.nick = 'blubb';
      doc.save(function(err) {
        console.error(err);
        mongoose.connection.db.dropDatabase(function () {
          mongoose.connection.close();
        });
      });
    });

  });
});

please open a ticket on the repo. :)