addEventListener("error", function (e) {
  var obj = {};
  for (var prop of ["message", "filename", "lineno"]) {
    obj[prop] = e[prop];
  }
  obj.type = "event";
  postMessage(obj);
});
onerror = function (message, filename, lineno) {
  var obj = {
    message,
    filename,
    lineno,
    type: "callback",
  };
  postMessage(obj);
  return false;
};
throw new Error("workerhello");