async function run() {
  const queue = []
  for (let i = 0; i < 100; i++) {
    queue.push(i)
  }

  while (queue.length) {
    console.log('loop')
    const items = queue.splice(0, 5)
    await Promise.all(items.map(process))
  }
}

async function process(item) {
  await randomDelay()
  console.log(item)
}

function randomDelay() {
  return new Promise(resolve => setTimeout(resolve, Math.random() * 100))
}

run().catch(console.error)