dfdf

1.js

async downloadSomething(mediaUrlList) {
  mediaUrlList.forEach(async mediaUrl => {
    const res = await axios.get(mediaUrl, { responseType: 'arraybuffer' });
    fs.writeFileSync(...);
    await delay(2000);
  });
}

2.js

async function test(urlList) {
  const promiseList = urlList.map(url => async () => axios.get(url));

  return promiseList.reduce((p, fn) => p.then((value) => {
    console.log('value', value);
    return delay(2000);
  }).then(fn), Promise.resolve());
}

test(['http://ip.jsontest.com', 'http://headers.jsontest.com', 'http://time.jsontest.com'])
  .then((value) => {
    console.log('value last', value.data);
  });

3.js

async function test(urlList) {
  if (urlList.length === 0) {
    return;
  }
  const errorUrlList = [];
  for (let i = 0; i < urlList.length; i += 1) {
      const url = urlList[i];
      try {
        const res = Math.random() > 0.5 ? await axios.get(url) : await axios.get(1);
        console.log(res.data);
      } catch (e) {
        errorUrlList.push(url);
      } finally {
        await delay(2000); // eslint-disable-line no-await-in-loop
      }
    }
}
test(errorUrlList);