Intercept unauthorized requests for Elm

intercept.js

XMLHttpRequest = class extends XMLHttpRequest {
  send() {
    const onreadystatechange = this.onreadystatechange;
    this.onreadystatechange = () => {
      console.log(this.readyState);
      if (typeof onreadystatechange === 'function') {
        this._onreadystatechange();
      }
    };
    super.send();
  }
};

const open = XMLHttpRequest.prototype.open;
const send = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.open = function(method, url) {
  return open.apply(this, arguments);
};

XMLHttpRequest.prototype.send = function(data) {
  function handleResponse() {
    if (this.status === 401) {
      app.ports.notAuthorizedIncoming.send(window.location.pathname);
    }
  }

  this.addEventListener("load", handleResponse);
  this.addEventListener("error", handleResponse);
  this.addEventListener("timeout", handleResponse);

  send.apply(this, arguments);
};