User with favourites and likes system in Mongoose schemas - node.js

Question

I want to create a DB with Users which also have a reference to another DB called "Library" which has "favourites" and "likes". I will show the idea here:
User Model
const userSchema = Schema({
username: {type: String, minlength: 4, maxlength: 10, required: true, unique: true},
email: {type: String, required: true, unique: true},
password: {type: String, required: true},
isVerified: { type: Boolean, default: false },
library: {type: Schema.Types.ObjectId, ref: 'Library'}
}, { timestamps: true});
Library Model
const librarySchema = new Schema({
likes: [{
likeId: {type: String},
mediaType: {type: String}
}],
favourites: [{
favId: {type: String},
mediaType: {type: String}
}],
user: {type: Schema.Types.ObjectId, ref: 'User'}
});
Can you please tell me if this is the right way to implement these models or if there is a better way?
At the moment if I try to call
User.findOne({email: 'xxx#xxx.com'}).populate('library').exec(function (err, library)
it doesn't find anything...
Library POST request
router.post('/favourites', passport.authenticate('jwt', {session: false}), function (req, res) {
const favouritesFields = {};
if (req.body.favId) favouritesFields.favId = req.body.favId;
if (req.body.mediaType) favouritesFields.mediaType = req.body.mediaType;
Library.findOne({user: req.user._id}).then(library => {
if (library) {
Library.update({user: req.user._id}, {$push: {favourites: favouritesFields}})
.then(library => res.json(library));
} else {
new Library({user: req.user._id, favourites: favouritesFields}).save().then(library => res.json(library));
}
});
});
User POST request
router.post('/signup', function (req, res) {
const {errors, isValid} = validateSignupInput(req.body);
if (!isValid) {
return res.status(400).json(errors);
}
// Check if email already exists
User.findOne({email: req.body.email}, function (user) {
if (user) {
return res.status(400).json({
title: 'Email already exists'
});
}
});
// Create and save the new user
let user = new User({
username: req.body.username.toLowerCase(),
email: req.body.email.toLowerCase(),
password: bcrypt.hashSync(req.body.password, 10)
});
user.save(function (err, result) {
if (err) {
return res.status(500).json({
title: 'An error occurred during the signup',
error: err
});
}
res.status(201).json({
title: 'User created',
obj: result
});

Answer 1

Your problem is not with the query you're making. there is no foundUser.library because one was never added.
You're adding users to libraries, but you're not adding libraries to your users. if you run the following code in your app:
Library.find({}).populate("user").exec(function(err, foundLibraries){
if (err){
console.log(err);
} else {
console.log(foundLibraries);
}
});
You would see that the libraries have their "user" properties, that when populated contain the entire user document as an object. But, the reason that isn't working for foundUser.library when you query for users is that foundUser.library was never assigned. you know how you're assigning the email, username and password when creating users, you have to do the same for the library property. Or, in your case, since a library is only created after the user, you can just set the value of user.library in the callback of creating/saving the library.