How to export model in mongoose?

Question

MongoDB

Hello gentlemen.
I started to actively study mongodb + mongoose + nodejs, I ran into a problem that I can’t solve for half a day, googling doesn’t help either.
there is a modelGroups.js file :

module.exports = function(mongoose)
{
    var db = mongoose.connection;
 
    var groupSchema = new mongoose.Schema({
        name:  {type: String, default: 'test' },
        name2: {type: String, default: 'none'}
    });
    
    // Специально, чтобы проверить, обьясню позже
    groupSchema.pre('save', function(next){
        console.log('saving ');
        return next();
    })
    // Специально, чтобы проверить, обьясню позже
    groupSchema.post('saved', function(next){console.log('saved');})
  
    var model = db.model('groupModel', groupSchema);
    return model;
}

and accordingly server.js :

var mongoose = require('mongoose');
var db = mongoose.createConnection('mongodb://localhost/notes');
db.on('error', console.error.bind(console, "connection error:"));
db.once('open', function callback () { console.log('Connected to database') });
// .............................................
app.get('/test', function(req, res){

    var model = require('./model/modelGroups.js')(mongoose);
    
    var m1 = new model({name:'test g 1'});
    m1.save(function(){
        res.send('saved');    
    });
});

And so an essence of a problem: does not save, stupidly.
The callback in m1.save is never called, just like post('save', ... ) is also not called/
The pre('save', ...) callback is called.
That is, it does not seem to reach the preservation.
Moreover, if all this is combined into one file, everything works. Please tell me what could be the problem.
Thanks in advance.

Answer 1

Googled.
For anyone interested, here:
stackoverflow.com/questions/10156623/mongoose-js-i...