References in another Schema - mongoose - node.js

Question

I'm doing some tests with MongoDB and NodeJS for a new project.
Searching the documentation I found that it is possible to make references to other collections and bring this data to JSON.
It was then that I decided to perform the following test:
const mongoose = require('mongoose')
const Schema = mongoose.Schema
const userSchema = new Schema({
name: {
type: String,
required: true,
unique: true
},
email: {
type: String,
required: true,
unique: true,
},
posts: [{
type: Schema.Types.ObjectId,
ref: 'Post'
}]
})
const userModel = mongoose.model('User', userSchema)
const postSchema = new Schema({
title: {
type: String
},
content: {
type: String
},
author: {
type: Schema.Types.ObjectId,
ref: 'User'
}
})
const postModel = mongoose.model('Post', postSchema)
const saveUser = new userModel({
name: 'user',
email: 'user#email.com'
})
saveUser.save()
const savePost = new postModel({
title: 'Lorem',
content: 'Lorem Ipsum',
author: saveUser._id
})
savePost.save()
postModel.find()
.populate('User')
.exec((err, post) => {
console.log(post)
})
However the return of JSON is:
{
_id: 5edd0c24a4f42b0e126f4b15,
title: 'Lorem',
content: 'Lorem Ipsum',
author: 5edd0c24a4f42b0e126f4b14,
__v: 0
}
When should it be:
{
_id: 5edd0c24a4f42b0e126f4b15,
title: 'Lorem',
content: 'Lorem Ipsum',
author: {
_id: 5edd0c24a4f42b0e126f4b14,
name: user,
email: user#email.com
},
__v: 0
}
Does anyone know any solution to this problem where I can insert for all my new Schemas?

Answer 1

Regarding populate you should provide the field name provided in postSchema. So should replace .populate('User') with .populate('author').
Since the post requires the author _id you should save the post only after the author is successfully saved
const saveUser = new userModel({
name: "user",
email: "user#email.com",
});
saveUser.save((err, data) => {
if (err) console.log(err);
else {
const savePost = new postModel({
title: "Lorem",
content: "Lorem Ipsum",
author: saveUser._id,
});
savePost.save();
}
});