Huge slowdown in resolution of job.finished() promise if add called with some delay after process

Created by: pcernek-spare

Description

Create a queue -> add a (trivial) processor function -> wait 100 ms -> add a job -> wait for job.finished(): takes ~5 seconds Do the same thing, but remove the "wait 100 ms" step: takes ~ 200 ms

Minimal, Working Test code to reproduce the issue.

index.js

const Queue = require('bull');
const Bluebird = require('bluebird')

const queue = new Queue('myTestQueue')
const delayMs = 100

queue.process((job) => {
  return job.data + 1
})
Bluebird.delay(delayMs).then(() => {
  queue.add(42).then((job) => {
    job.finished().then(process.exit)
  })
})

Run time node index.js: takes ~ 5 s Set delayMs to 0 to remove the delay, run the same thing again: takes ~200 ms

Bull version

3.4.2

Additional information

Inserting some print statements suggests that the job gets processed very fast -- the bottleneck seems to be in the job.finished() promise resolving.