<style>
  ruby {
    columns: 1px;
  }
  ruby::before {
    display: block;
    content: url();
  }
</style>
<script>
  if (window.testRunner)
    testRunner.dumpAsText();
  onload = () => {
    document.styleSheets[0].insertRule(`ruby {}`);
  };
</script>
<body>
<ruby>PASS if no crash or assert.</ruby>
</body>