fune/devtools/client/webreplay/mochitest/examples/doc_rr_error.html

<html lang="en" dir="ltr">
<body>
<div id="maindiv" style="padding-top:50px">Hello World!</div>
</body>
<script>
const cpmm = SpecialPowers.Services.cpmm;
function recordingFinished() {
  cpmm.sendAsyncMessage("RecordingFinished");
}
var number = 0;
function f() {
  number++;
  document.getElementById("maindiv").innerHTML = "Number: " + number;
  if (number >= 10) {
    window.setTimeout(recordingFinished);
    return;
  }
  window.setTimeout(f, 1);
  throw new Error("Number " + number);
}
window.setTimeout(f, 1);
</script>
</html>