Rafik-Belkadi-malou

import {Product, IProduct} from './product'
import {Order, IOrder} from './order'

const main = async () => {
  // products to insert
  const productsPayload: IProduct[] = [{name: 'Pokemon', price: 20, stock: 40}, {name: 'Socks', price: 10, stock: 50}]
  // Inserted products result typed with the interface IProduct
  const products: IProduct[] = await Product.insertMany(productsPayload)
  
  // Order to insert

Rafik-Belkadi-malou

import { Schema, model } from 'mongoose'
import { IProduct } from './product'

// Utility type which you can put in your utils file
type ID = Schema.Types.ObjectId

export interface IOrder {
    _id?: ID
    // Represents the relation between the order and the product
    productsIds: ID[]

Rafik-Belkadi-malou

import { Schema, model } from 'mongoose'

// Utility type which you can put in your utils file
type ID = Schema.Types.ObjectId

export interface IProduct {
    // Optional so it is easier to use when trying to create a new document
    _id?: ID
    name: string
    price: number