NestJS and mongo two way relation between post schema and user schema - mongodb

Question

I am new to nest and mongo I am trying to do a relation where a user schema embeds a posts array with ids of posts and in the posts schema I want to embed the author which is a user schema with the user id but I keep running into this error in my console
Error: Cannot determine a type for the "Post.author" field (union/intersection/ambiguous type was used). Make sure your property is decorated with a "#Prop({ type: TYPE_HERE })" decorator.
this is my code
UserSchema
import { Prop, Schema, SchemaFactory } from "#nestjs/mongoose";
import { Document } from "mongoose";
import { Post, PostSchema } from "src/posts/entities/post.entity";
export type UserDocument = User & Document;
#Schema()
export class User extends Document{
#Prop({ index: true})
name: string;
#Prop([{ type: PostSchema}])
posts: Post[]
}
export const UserSchema = SchemaFactory.createForClass(User)
PostSchema
import { Prop, Schema, SchemaFactory } from "#nestjs/mongoose";
import { Document } from "mongoose";
import { User, UserSchema } from "src/users/entities/user.entity";
export type PostDocument = Post & Document;
#Schema()
export class Post extends Document{
#Prop({index: true})
title: string;
#Prop({index:true})
body: string;
#Prop({type: UserSchema})
author: User;
}
export const PostSchema = SchemaFactory.createForClass(Post)
at the end what I am trying to achive in my database is this
users collection
{
"_id" : "U1",
"name":"user1",
"posts": [
{
"_id": "P1",
"title":"title 1",
"body":"body 1"
}
]
}
posts collection
{
"_id" : "P1",
"title":"title 1",
"body":"body 1",
"author": {
"_id": "U1",
"name":"user1",
}
}
I am trying to embed doucments into each other with the ids so I can read fast and use the ids to update

Answer 1

your user schema have a problem.
the way you define an array is wrong. use this one :
#Prop({type: [PostSchema]})
posts: Post[]