Post middleware hooks not triggered when referenced from a model.

[EliKrumholz]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?
Mongoose >=4.8.0 is not running post middleware in the following case.

If the current behavior is a bug, please provide the steps to reproduce.

var mongoose = require('mongoose');
var events = require('events');
var ThingEvents = new events.EventEmitter();

mongoose.connect(`mongodb://localhost:27017/mongoose-bug`);

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

var Thing = mongoose.model('Thing', ThingSchema);

ThingEvents.on('test event', function(doc) {
  console.log('test event emitted');
});

Thing.schema.post('save', function(doc) {
  ThingEvents.emit('test event', doc);
});

Thing.create({name: 'test'});

What is the expected behavior?
Mongoose 4.7.9 logs test event emitted to the console, as expected.
Mongoose >=4.8.0 does not.

Please mention your node.js, mongoose and MongoDB version.
Node: 6.9.5
Mongoose: 4.8.1
MongoDB: 3.2.10

[EliKrumholz]

Sorry, no need for an event emitter, here is a simpler example:

var mongoose = require('mongoose');

mongoose.connect(`mongodb://localhost:27017/mongoose-bug`);

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

var Thing = mongoose.model('Thing', ThingSchema);

Thing.schema.post('save', function(doc) {
  console.log('Post hook triggered');
});

Thing.create({name: 'test'});

[sobafuchs]

Hey @EliKrumholz, so mutating the underlying schema after the Thing model has been created by mongoose.model() isn't a supported behavior. Make sure you define all your hooks before calling mongoose.model().

[EliKrumholz]

Got it, thanks for the reply @varunjayaraman.