testhooks.js

//running the below produces

//  ~/tmp/mongoose-events-test ⮀  ⮀  ⮀ node test                                                                                                                ⮂ ruby-2.2.1 
// this was new: 
// saved:  { __v: 0, name: 'emitUpdate', _id: 55ea6f4b05de60396e95e961 }
// saved:  { _id: 55ea6f4b05de60396e95e961, name: 'aasdf', __v: 0 }
// saved
// this was removed:  { __v: 0, name: 'emitUpdate', _id: 55ea6f4b05de60396e95e961 }
var mongoose = require('mongoose');
mongoose.connect('localhost', 'events');

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

// plumbing
schema.pre('save', function (next) {
  this._wasnew = this.isNew;
  next();
});
schema.post('save', function () {
  if (this._wasnew) this.emit('new')
  else this.emit('update');
});

// listeners
schema.post('new', function (data) {
   console.log('this was new: ') ;
});

schema.post('update', function (data) {
  console.log('this was an update: ');
});


schema.post('save', function(data) {
        console.log('saved: ', this)
})

schema.post('remove', function (data) {
  console.log('this was removed: ', this);
  mongoose.connection.close();
});

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

mongoose.connection.on('open', function () {

  var a = new A({ name: 'emitUpdate' });

  a.save(function (err, a) {

    if (err) return console.error(err.stack||err);

    A.findById(a, function (err, doc) {

      if (err) console.error(err.stack||err);

      doc.name = 'aasdf';
      doc.save(function (err) {
        console.log("saved")

        a.remove(function(){
         // mongoose.connection.close();
        })
      });
    });
  })
});