1062.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var assert = require('assert')

console.log('\n===========');
console.log('    mongoose version: %s', mongoose.version);
console.log('========\n\n');

mongoose.set('debug', true);
mongoose.connect('localhost', 'testing_1062');
mongoose.connection.on('error', function () {
  console.error('connection error', arguments);
});

var schema = new Schema({
    category: { type: String, unique: true }
  , counts: {}
});

schema.statics.test = function (category, keys, cb) {
  var conditions = {'category': category};
  var update = {'$inc': {'counts.total': 1}};
  var options = {'safe': true, 'upsert': true, 'multi': false};

  var key;
  for (var i = 0, len = keys.length; i < len; i++) {
    key = keys[i];
    update['$inc']['counts.' + key] = 1;
  }

  return this.update(conditions, update, options, cb);
}

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

mongoose.connection.on('open', function () {
  mongoose.connection.db.dropDatabase(function () {
    var a = new A({ category: 'testing' });

    a.save(function (err, a) {
      if (err) return done(err);

      A.test('testing', 'a b.e.f c'.split(' '), function (err, numAffected) {
        console.error(arguments);
        done(err);
      });

    })
  })
});

function done (err) {
  if (err) console.error(err.stack);
  mongoose.connection.db.dropDatabase(function () {
    mongoose.connection.close();
  });
}