How do I download multiple things at once?

index.js

// Imagine we have a bunch of URLs we need to check (download and check their status code)
const urls = [
  // Most of these are known to be good...
  'https://damontui.blogspot.com/feeds/posts/default?alt=rss',
  'https://dev.to/feed/henryzerocool/',
  'https://danielsirkovich.blogspot.com/feeds/posts/default?alt=rss',
  'https://abdulosd.blogspot.com/feeds/posts/default?alt=rss',
  'http://palak-chawla.blogspot.com/feeds/posts/default?alt=rss',
  'http://zjjiang2.blogspot.com/feeds/posts/default/-/categorylabel?alt=rss',
  'https://dev.to/feed/phast184',
  'https://hyunjijanelee.blogspot.com/feeds/posts/default/-/Open-Source?alt=rss',
  'https://osdnathanp.wordpress.com/feed/',
  'https://medium.com/feed/@random4900',

  // But this one will fail
  'http://tea.cesaroliveira.net/archives/tag/seneca/feed',
];

// We need to download these, let's use node-fetch (`npm install node-fetch`)
const fetch = require('node-fetch');

// fetch() needs a `url`, and it will return a Promise. So we need to
// transform our Array-of-URLs into an Array-of-Promises.  Let's first
// write a function that takes a URL, and returns a Promise that will
// get resolved with an Object containing the URL and its Status Code.
// We'll use async/await syntax, and specify that our function is `async`,
// meaning that it "returns a Promise" and that we'll be "using the await keyword."
async function checkUrl(url) {
  // We need try/catch to deal with fetch()'s Promise erroring
  try {
    // We will download this resource, and await the response. To show
    // what's happening, we'll log that we're starting
    console.log(`Starting download for ${url}`);
    const res = await fetch(url);
    // If we get here, it worked, and we'll resolve with the url + status
    return { url, status: res.status };
  } catch(err) {
    // If we get here, we encountered an error, so we'll send back -1 to indicate an error
    return { url, status: -1 };
  } finally {
    // We're done processing this URL, log it so you can see things finish
    console.log(`Finished download of ${url}`);
  }
}

// Transform our Array-of-URLs to an Array-of-Promises, and start them all.
const promises = urls.map(checkUrl);

// We'd like to wait on *all* of these fetch() Promises to complete, so
// we'll use Promise.all() to get a single Promise from our Array-of-Promises
Promise
  .all(promises)
  .then(results => console.table(results))
  .catch(err => console.error(err));


/**

$ node index.js

Starting download for https://damontui.blogspot.com/feeds/posts/default?alt=rss
Starting download for https://dev.to/feed/henryzerocool/
Starting download for https://danielsirkovich.blogspot.com/feeds/posts/default?alt=rss
Starting download for https://abdulosd.blogspot.com/feeds/posts/default?alt=rss
Starting download for http://palak-chawla.blogspot.com/feeds/posts/default?alt=rss
Starting download for http://zjjiang2.blogspot.com/feeds/posts/default/-/categorylabel?alt=rss
Starting download for https://dev.to/feed/phast184
Starting download for https://hyunjijanelee.blogspot.com/feeds/posts/default/-/Open-Source?alt=rss
Starting download for https://osdnathanp.wordpress.com/feed/
Starting download for https://medium.com/feed/@random4900
Starting download for http://tea.cesaroliveira.net/archives/tag/seneca/feed
Finished download of http://tea.cesaroliveira.net/archives/tag/seneca/feed
Finished download of https://dev.to/feed/henryzerocool/
Finished download of https://dev.to/feed/phast184
Finished download of https://osdnathanp.wordpress.com/feed/
Finished download of http://zjjiang2.blogspot.com/feeds/posts/default/-/categorylabel?alt=rss
Finished download of https://damontui.blogspot.com/feeds/posts/default?alt=rss
Finished download of https://danielsirkovich.blogspot.com/feeds/posts/default?alt=rss
Finished download of https://hyunjijanelee.blogspot.com/feeds/posts/default/-/Open-Source?alt=rss
Finished download of https://medium.com/feed/@random4900
Finished download of https://abdulosd.blogspot.com/feeds/posts/default?alt=rss
Finished download of http://palak-chawla.blogspot.com/feeds/posts/default?alt=rss
┌─────────┬────────────────────────────────────────────────────────────────────────────────┬────────┐
│ (index) │                                      url                                       │ status │
├─────────┼────────────────────────────────────────────────────────────────────────────────┼────────┤
│    0    │          'https://damontui.blogspot.com/feeds/posts/default?alt=rss'           │  200   │
│    1    │                      'https://dev.to/feed/henryzerocool/'                      │  200   │
│    2    │       'https://danielsirkovich.blogspot.com/feeds/posts/default?alt=rss'       │  200   │
│    3    │          'https://abdulosd.blogspot.com/feeds/posts/default?alt=rss'           │  200   │
│    4    │         'http://palak-chawla.blogspot.com/feeds/posts/default?alt=rss'         │  200   │
│    5    │   'http://zjjiang2.blogspot.com/feeds/posts/default/-/categorylabel?alt=rss'   │  200   │
│    6    │                         'https://dev.to/feed/phast184'                         │  200   │
│    7    │ 'https://hyunjijanelee.blogspot.com/feeds/posts/default/-/Open-Source?alt=rss' │  200   │
│    8    │                    'https://osdnathanp.wordpress.com/feed/'                    │  200   │
│    9    │                     'https://medium.com/feed/@random4900'                      │  200   │
│   10    │            'http://tea.cesaroliveira.net/archives/tag/seneca/feed'             │   -1   │
└─────────┴────────────────────────────────────────────────────────────────────────────────┴────────┘
**/