Need Promise.all but without running in parallel

Question

How do I make the last console.log line of the code snippet execute only after ALL the updateInkLevel functions finish executing?

  for (let i = 0; i < activeDevices.length; i++) {

    updateInkLevel(accessToken, deviceId, logIndex) 
    await new Promise((r) => setTimeout(r, 500)) // add a small sleep delay
  }
  console.log("everything completed")

updateInkLevel is an async function, returning a promise. I was thinking of using Promise.all, but that would run each iteration in parallel, which is not I want here. Here, I'm firing each iteration sequentially one at a time, with a small sleep delay before firing the next call.

I'm looking for something like Promise.all, but without running in parallel.

References, Is Node.js native Promise.all processing in parallel or sequentially?

Answer 1

await new Promise((r) => setTimeout(r, 500)) // add a small sleep delay

Don't do that.

You are guessing how long updateInkLevel will take

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Just await the promise returned by updateInkLevel.

That will pause the loop until the promise resolves.

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I was thinking of using Promise.all, but that would run each iteration in parallel, which is not I want here.

Are you sure you don't want them in parallel? That would often be more efficient.