schema.pre() is not a function

Question

I am trying to add markup and sanitize my input but I keep getting an error; This is my code;

const mongoose = require('mongoose');
const slug = require('slugify');
const createDomPurify = require('dompurify');
const marked = require('marked');
const {JSDOM} = require('jsdom');
const dompurify = createDomPurify( new JSDOM().window);

const CPASchema = {
   

   //SOME PART OF THIS CODE BUT UNNECESSARY TO THE QUESTION 

    answer:{
        type:String
    },

    sanitizedHTML:{
        type: String,
        required: true
    }
}

CPASchema.pre('validate', async function(data, next){ 

    if(data.answer) {
         console.log('JUST BEFORE SANITIZING')
        data.sanitizedHTML = await dompurify.sanitize(marked(data.answer));
    }
    next()

})

module.exports = mongoose.model('CPASchema', CPASchema);

This is the error I keep getting

CPASchema.pre('validate', async function(data, next){
          ^

TypeError: CPASchema.pre is not a function

EDIT I have tried changing the mongoose verion but that did not help

Answer 1

You're calling the mongoose's methods before introducing your schema.

The part of your schema is nothing just a simple Javascript object, you need to pass it to the mongoose and use the returned object.

The below snippet might help you to understand the behavior.

const schema = new mongoose.Schema({ name: String });

schema.pre('save', () => console.log('Hello from pre save'));