<!DOCTYPE html>
<title>SyntaxError thrown when matching CSS-wide keyword</title>
<link rel="help" href="https://drafts.csswg.org/css-font-loading/#font-face-set-load">
<link rel="help" href="https://drafts.csswg.org/css-font-loading/#find-the-matching-font-faces">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>

  function load_on_worker(keyword) {
    return new Promise((resolve, reject) =>{
      var blob = new Blob([`
        self.fonts.load('${keyword}').then(
          ()=>{ self.postMessage('success') },
          (e)=>{ self.postMessage(e) }
        );
      `]);
      var blob_url = window.URL.createObjectURL(blob);
      let worker = new Worker(blob_url);
      worker.onmessage = msg => {
        if (msg === 'success')
          resolve(msg.data)
        else
          reject(msg.data)
      }
    });
  }

  // https://drafts.csswg.org/css-font-loading/#find-the-matching-font-faces
  // forbids CSS-wide keywords as the value of the font given to the
  // load method (equivalent to the font shorthand).  Note that the test
  // for this case will also pass when the system-wide keyword simply
  // isn't supported, since the syntax won't be valid syntax for the
  // 'font' shorthand.
  // https://drafts.csswg.org/css-fonts-4/#family-name-syntax also
  // forbids using the CSS-wide keywords as unquoted keywords within
  // <font-family>.
  for (let [description_prefix, syntax_prefix] of [["", ""], ["value with ", "medium "]]) {
    for (let keyword of ["initial", "inherit", "unset", "default", "revert", "revert-layer"]) {
      promise_test(test => {
        return promise_rejects_dom(test, 'SyntaxError', document.fonts.load(`${syntax_prefix}${keyword}`));
      }, `Loading ${description_prefix}CSS-wide keyword "${keyword}" causes SyntaxError (document)`)
      promise_test(test => {
        return promise_rejects_dom(test, 'SyntaxError', load_on_worker(`${syntax_prefix}${keyword}`));
      }, `Loading ${description_prefix}CSS-wide keyword "${keyword}" causes SyntaxError (worker)`)
    }
  }

</script>
