cats.js

if (typeof process !== 'undefined' && process.exit)
(async () => {
    const fs = require('fs').promises;
    let cont = (await fs.readFile(__filename)).toString();
    cont = cont.replace(/^.+?(?=\(\(d\) => \{)/s, '');
    cont = cont.replace(/(?<!(?:function|typeof|const|let))\s+(?=(?:[^\'"]*[\'"][^\'"]*[\'"])*[^\'"]*$)/gs, '');
    console.log('javascript:' + cont);
    process.exit(0);
})();
else
((d) => {

    function update() {
        fetch("https://api.giphy.com/v1/gifs/random?api_key=y8CpAcHAapCxnArZIrZHCkSktr8y3IcQ&tag=cat")
          .catch(err => console.error('Unable to fetch cats', err))
          .then(rsp => rsp.text())
          .catch(err => console.error('Unable to get cats response test', err))
          .then(txt => JSON.parse(txt))
          .catch(err => console.error('Unable to parse cats response json', err))
          .then(json => ['data', 'images', 'original', 'url'].reduce((a, n) => a ? a[n] : undefined, json))
          .then(url => {
              d.body.innerHTML = tmpl(url);
              const btnCatz = d.getElementById('catz');
              btnCatz.addEventListener('click', update);
          });
    }
    function tmpl(url) {
        return  [
        '<h1>Random Cats</h1>',
        '<button id="catz">More Please!</button>',
        '<div>',
         url ? '<img src="' + url+ '">' : '<p>Failed to load cats</p>',
        '</div>'
        ].join('');
    }
    d.body = d.createElement('body');
    update();
})(typeof document !== 'undefined' ? document : {});