Question: How can I track the progress of a job in BullMQ?

Answer

In BullMQ, you can track the progress of a job by using the progress method. This is useful when dealing with long-running jobs where you'd like to provide some kind of feedback or persistence of progress over time.

To set the progress of a job, you would typically do it from within the process function itself:

queue.process(async (job) => {
  // Some processing here...

  // You can set the progress as an integer value or as an object
  await job.updateProgress(42);
  // or
  await job.updateProgress({ step: 1, totalSteps: 5 });

  // Continue processing...
});

You can also listen to the progress updates using on event listener:

job.on('progress', progress => {
  console.log(`Job ${job.id} is progressing: `, progress);
});

Remember that the progress data you send can be any valid JSON data type. This means you could send an object with more complex and detailed information if needed, but keep in mind that this will increase the network overhead, so it's a balance between level of detail and performance impact.