promise-all-with-concurrency.ts

export const promiseAllWithConcurrency = async <T>(
  queue: (() => Promise<T>)[],
  concurrency: number = 1
) => {
  let index = 0;
  const results: T[] = [];

  const execThread = async () => {
    while (index < queue.length) {
      const curIndex = index++;
      results[curIndex] = await queue[curIndex]();
    }
  };

  const threads = [];
  for (let thread = 0; thread < concurrency; thread++)
    threads.push(execThread());

  await Promise.all(threads);

  return results;
};