akf-forum/models/Category.js

const mongoose = require("mongoose")

const schema = new mongoose.Schema({
    name: { type: String, unique: true },
    desp: String, position: Number,
    id: { type: String, unique: true },
    authorID: { type: String }

});
schema.methods.takeId = async function () {
    this.id = String(await model.count() || 0);
    return this;
}
const model = mongoose.model('category', schema);

module.exports = model;