NodeJS with Bull: Cant run job / queue twice, getting : Error: Cannot define the same handler twice __default__

Question

I created a job that allows me to create a pdf file with dynamic content inside. It works when I do a post request the first time and start the job, but the second time it fails with the errror above.

what I basically have in the invoiceWorker.ts file is this:

const bull = require("bull")
import { Job } from "bull"

import { Order } from "./../entities/order"
const queue = new bull("pdf-generation")
const pdfKit = require("pdfkit")
const fs = require("fs")

export async function startProcess() {
  await queue.close()
  queue.process(async (job: Job) => {
    console.log(`Processing Job with id ${job.id}`)
    await generatePdfInvoice(job.data)

    console.log(job.finished())
  })
}

async function generatePdfInvoice(data: Order) {
  let doc = new pdfKit()
  const pdfName = data.id + ".pdf"

  var s = doc.pipe(fs.createWriteStream(pdfName))

  doc
    .fontSize(14)
    .text(
      `It doesnt take long... we received your order, ${data.customer.username}`,
      100,
      100
    )

  doc
    .moveDown(2)

    .fontSize(14)
    .text(`The prize of your order is: ${data.burgers[0].totalPrize} $`)

  doc
    .moveDown(2)

    .fontSize(14)
    .text(`We are delivering it to: ${data.customer.adress} $`)

  doc.end()

  console.log(`Generated PDF document`)
  await queue.close()
}

the start process function adds a process handler and runs the generatedPDfInvoice function which basically creats a pdf file.

In another file I got:

import { Job } from "bull"
import { Order } from "../entities/order"

const bull = require("bull")

export const queue = new bull("pdf-generation")

export async function startJob(invoiceData: Order) {
  console.log("startjob")
  let job: Job = await queue.add(invoiceData)
}

which adds a job to the queue. In my controller I have the following:`

 order = await orderRepo.save(order)
      await startJob(order)
      console.log(order)
      await startProcess()

``````````````

where I just run those functions.


Why I am getting this error? Am I not allowed to run queue.process() every request? If not,
how do I structure my code properly?

Thx:)