Implementing a pool of requests

pool.js

const fs = require("fs");
const path = require("path");
const axios = require("axios");
const { pipeline } = require("stream/promises");

const api = axios.create({
  baseURL: "https://pokeapi.co/api/v2/pokemon",
});
const requestsInParallel = 3;
const limit = 10;
let processed = 0;

let id = 1;
const pool = [];

const getPokemonBy = async (id) =>
  api.get(`/${id}`).then(({ data }) => {
    const {
      name,
      sprites: {
        other: {
          "official-artwork": { front_default: artwork },
        },
      },
    } = data;
    const ext = path.extname(artwork);

    return {
      filename: `${name}${ext}`,
      name,
      artwork,
    };
  });

const downloadImage = async (url, filename) =>
  api
    .get(url, { responseType: "stream" })
    .then(({ data: stream }) =>
      pipeline(stream, fs.createWriteStream(filename))
    );

const push = () => {
  while (pool.length - processed < requestsInParallel && id <= limit) {
    pool.push(
      getPokemonBy(id)
        .then(({ filename, name, artwork }) =>
          downloadImage(artwork, filename).then(() => name)
        )
        .then((name) => {
          // delay the requests
          return new Promise((resolve) => {
            setTimeout(() => {
              processed++;
              console.log(`(${processed}/${limit}) ${name} processed`);
              resolve();
            }, 500);
          });
        })
    );
    id++;
  }

  return Promise.all(pool);
};

const run = async () => {
  if (processed < pool.length || processed < limit) {
    return push().then(run);
  }
  return pool;
};

console.time("Pipeline took");
run().then(() => {
  console.timeEnd("Pipeline took");
});