schema.pre() is not a function-CodePudding

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

CodePudding user response：

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'));