Tool to convert Fullscreen from Anolis to Bikeshed

convert.html

<meta charset=utf-8>
<textarea style="width: 100%; height:100%"></textarea>
<script>
function stripIntro(doc) {
  while (doc.body.firstChild.id != 'conformance')
    doc.body.firstChild.remove();
}
function anolisToBikeshed(doc) {
  // remove all internal markup from the IDL block
  var idl = doc.body.querySelector('pre.idl');
  idl.textContent = idl.textContent;
  // loop over and transform all elements/attributes
  const elements = [].slice.call(doc.body.querySelectorAll('*'));
  for (let e of elements) {
    const attributeNames = [].map.call(e.attributes, a => a.name);
    if (e.localName == 'span') {
      // <span> => <a>
      let a = doc.createElement('a');
      for (let name of attributeNames)
        a.setAttribute(name, e.getAttribute(name));
      while (e.firstChild)
        a.appendChild(e.firstChild);
      e.parentNode.replaceChild(a, e);
      e = a;
    }
    for (let name of attributeNames) {
      const value = e.getAttribute(name);
      switch (name) {
        case 'data-anolis-spec':
          // the <pre class=anchors> block replaces data-anolis-spec
          e.removeAttribute(name);
          break;
        case 'data-anolis-ref':
          // <span data-anolis-ref>CSS</span> => [[!CSS]]
          var text = document.createTextNode('[[!' + e.textContent + ']]');
          e.parentNode.replaceChild(text, e);
          break;
        case 'title':
          if (value) {
            if (e.localName == 'code') {
              // wrap in <a>, Bikeshed doesn't autolink <code>
              var a = doc.createElement('a');
              e.parentNode.replaceChild(a, e);
              a.appendChild(e);
            } else {
              if (value.startsWith('concept-')) {
                // drop and fix with <pre class=link-defaults>
              } else {
                // title="foo-bar" -> lt="foo bar"
                const ltValue = value.replace(/-/g, ' ');
                // skip plural forms, Bikeshed understand
                if (e.textContent != ltValue + 's')
                  e.setAttribute('lt', ltValue);
              }
            }
          }
          e.removeAttribute(name);
          break;
      }
    }
  }
}
function serialize(doc) {
  var html = doc.body.innerHTML;
  // strip </p> and similar
  html = html.replace(/<\/(p|li|dd|dt|th|td|tr|thead|tbody)>/g, '');
  // attr="" => attr
  html = html.replace(/=""/g, '');
  // &gt; => >
  html = html.replace(/&gt;/g, '>');
  // attr="no-whitespace" => attr=no-whitespace
  html = html.replace(/="([^ ]+)"/g, '=$1');
  return html;
}
document.querySelector('textarea').addEventListener('paste', event => {
  setTimeout(() => {
    const input = event.target.value;
    var parser = new DOMParser();
    var doc = parser.parseFromString(input, "text/html");
    stripIntro(doc);
    // if anolisToBikeshed() is skipped, there are no interesting differences
    anolisToBikeshed(doc);
    var output = serialize(doc);
    event.target.value = output;
    event.target.select();
  }, 0);
});
</script>