Fake progress update for bullMQ worker

fakeProgress.ts

import { Job } from 'bullmq';
import ms from 'ms';


// taken from https://github.com/tanem/react-nprogress/blob/ec007096e08af79179b8530a4915e225075d37ac/src/clamp.ts
function clamp(num: number, lower: number, upper: number): number {
  num = num <= upper ? num : upper;
  num = num >= lower ? num : lower;

  return num;
}

// taken from https://github.com/tanem/react-nprogress/blob/ec007096e08af79179b8530a4915e225075d37ac/src/increment.ts
function increment(progress: number): number {
  let amount = 0;
  if (progress >= 0 && progress < 0.2) {
    amount = 0.1;
  } else if (progress >= 0.2 && progress < 0.5) {
    amount = 0.04;
  } else if (progress >= 0.5 && progress < 0.8) {
    amount = 0.02;
  } else if (progress >= 0.8 && progress < 0.99) {
    amount = 0.005;
  }

  return clamp(progress + amount, 0, 0.994);
}

export function startFakeProgress(job: Job) {
  let progress = 0;

  const id = setInterval(async () => {
    await job.updateProgress(Math.floor(progress * 100));
    progress = increment(progress);
  }, ms('1sec'));

  return async (error?: Error) => {
    clearInterval(id);

    if (!error) {
      await job.updateProgress(100);
    }
  };
}

worker.ts

import { Worker } from 'bullmq';
import { fakeProgerss } from './fakeProgress';

const worker = new Worker(queueNames.predictions, async (job) => {
  const finishWork = await startFakeProgress(job);

  try {
    // do your work
  } catch (e) {
    finishWork(e);
    throw e;
  }

  finishWork();
});

This Gists uses the same fake progress function as nprogress does.