tryMySQL.js

const mysql = require('mysql')
const config = ini.parse(fs.readFileSync('../credentials.ini', 'utf-8')) /* only happens once on server start */
const db = mysql.createPool(config.labsdb)
    

    tryMySQL(input){
        return new Promise((resolve, reject) => {
            if(!input.mysql) return resolve(input)            
            db.getConnection((err, conn) => {
                if(err) reject({dbError: err})
                conn.query(input.mysql)
                    .on('end', () => conn.release() || resolve(input))
                    .on('error', err => reject({queryError: err}))
                    .on('fields', fields => this.send({fields}))
                    .on('result', row => this.send({row}))
            })
        })
    }

I think this strategy of rejecting with err and resolving with original input is a good way to do the promise chain recursive array.
If a 'try' is unnecessary in the case of 'post-chat' then it just moves to the next one

in the case of pre-chat, maybe you'll only try if some kind of err exists (Array.some(Object.keys(input).includes('err'))

Very good for this.send to return the result as well so these try-promises can go downstream