Mongoose model as an ES6 class with inheritance chain

[Tony John]

I was trying to create a ES6 class hierarchy to implement a caching layer between mongoose and mongodb queries. I saw this PR https://github.com/Automattic/mongoose/pull/4668 and based on that wrote the below code.

   

'use strict'

    

    const mongoose = require('mongoose');

    mongoose.connect("mongodb://host:port/db", {});

    mongoose.connection.on('error', console.error.bind(console, 'DB connection failed', arguments));

    mongoose.connection.once('open', console.log.bind(console, 'Connected to DB'));

    

    class Base extends mongoose.Model {

    save() {

    console.log('Base class save()')

    return super.save();

    }

    

    findOne(query){

    console.log('Base class find...');

    return super.findOne(query);

    }

    }

    

    class Derived extends Base{

    save(){

    console.log('Derived class save()');

    super.save();

    }

    

    static getOne(){

    console.log('Derived class Get one');

    return this.findOne({});

    }

    }

    

    let usersSchema = new mongoose.Schema({ name: String })

    

    usersSchema.loadClass(Derived);

    

    let User = mongoose.model(Derived, usersSchema, 'users');

    

    setTimeout(function(){

    User.getOne()

    .then(user => console.log('Found user...', user));

    

    let newUser = new User();

    console.log('newUser instance of Derived ? ', (newUser instanceof Derived));

    console.log('newUser instance of Base ? ', (newUser instanceof Base));

    newUser.name = 'Tony';

    newUser.save()

    .then(result => console.log('Saved', result));

    }, 2000);

Since the methods are overridden in the derived class, I was expecting the calls to the methods in Derived class will in turn call the Base class and then I could add additional logic in Base class before / after queries. 

Below is the output which I am getting, which indicates that the method invocations are not hitting the Derived/Base class. 

Output

   

Connected to DB
Derived class Get one
newUser instance of Derived ?  true
newUser instance of Base ?  true
Base class save()
Found user... { _id: 58ec765f9dd99f049c2a833b, name: 'Tony', __v: 0 }

When I call the save method, it does not hit the Derived class and when I call the getOne static method in *Derived* class, the call does not hit the findOne method in Base class. I am not sure where am I going wrong. Can anyone throw some light on this.

[Tony John]

Haven't heard from anyone. Is there any problem with the below code? or it's a bug?

[justin hyland]

Tony, not sure if you found this yet, but you should read over the Mongoose Advanced Schemas documentation.

I was having the exact same problem as you, so hopefully this helps.