CloudFlare worker - Enrich tweet using mircolink.io

index.js

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) 
{
    const url = new URL(request.url);
    const id  = url.pathname;

    const tweet = await fetchTweet(id);

    let result = new HTMLRewriter()
      .on('a:first-of-type', { async element(element) {

            if(element.hasAttribute('href')) {
                const link = await fetchLink(element.getAttribute('href'));

                if(link.status == 'success' && link.data.image) {
                    element.after('<img href="'+link.data.image.url+'" >', { html: true });
                } 
            }           

      }}).transform(new Response(tweet.html))

  tweet.html = await result.text();    

  return new Response(JSON.stringify(tweet), {
      status: 200,
      headers: {
        "content-type": "application/json;charset=UTF-8"
      }
    })
}

async function fetchTweet(id)
{
    const tweet = await fetch('https://publish.twitter.com/oembed?omit_script=1&url=https://twitter.com/_/status'+id)
      .then((response) => {
        return response.json()
      });

      console.log(tweet.html);

    return tweet;
}

async function fetchLink(url)
{
    const link = await fetch('https://api.microlink.io/?url='+url)
        .then((response) => {
            return response.json()
        }); 

    return link;              
}