unshift does not work as expected in a retry demo.

[aguegu]

import fastq from 'fastq';

const worker = async ({ index, retries }) => {
  console.log({ index, retries });
  throw new Error('Oops');
};

const queue = fastq.promise(worker, 1);

queue.error((err, { index, retries }) => {
  if (err) {
    if (retries) {
      queue.unshift({ index, retries: retries - 1 });
      // queue.push({ index, retries: retries - 1 });
    } else {
      console.log({ err }, 'all retries failed');
    }
  }
});

queue.push({ index: 0, retries: 3 });

await queue.drain();

I would like to implement a simple retry mechanism with fastq(1.15.0)'s error handler, like every task got 3 more chances. So for the following tries, I would prefer them to be unshifted into the queue. But the log looks like:

{ index: 0, retries: 3 }
{ index: 0, retries: 2 }

What I expected is the log like this which is replacing unshift() with push() :

{ index: 0, retries: 3 }
{ index: 0, retries: 2 }
{ index: 0, retries: 1 }
{ index: 0, retries: 0 }
{
  err: Error: Oops
      at worker (file:///home/agu/workspace/TimeFabric/livefeed/api/src/queDemo.js:5:9)
      at asyncWrapper (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:213:12)
      at Task.release (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:149:16)
      at worked (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:201:10)
} all retries failed

so the worker got executed 4 times before giving up.

I do not know why unshift only got the work executed once. But unshift is what I want in this queue, because an immediate retry may just get it done. It does not have to retry it later or wait all over again.

[mcollina]

You've found yourself a bug! If you would like to send a PR, it would be amazing. Otherwise, I'll take a look when I can.

[aguegu]

Thanks @mcollina for your encouragement. Feel proud and lucky to contribute.

[catdevnull]

fixed?

[aguegu]

Fixed with #78