PromiseAllWithLimit.ts

export async function promiseAllWithLimit<T>(
    promiseGenerators: Array<() => Promise<T>>,
    poolLimit: number
): Promise<T[]> {
    let currentIndex = poolLimit - 1;
    const total = promiseGenerators.length;
    const results: T[] = Array(total);

    const next = async (index: number): Promise<void> => {
        if (index >= total) {
            return;
        }

        return promiseGenerators[index]().then((result) => {
            results[index] = result;
            currentIndex++;
            return next(currentIndex);
        });
    };

    const workers = Array(poolLimit)
        .fill(null)
        .map((_, index) => next(index));

    return Promise.all(workers).then(() => results);
}