JavaScript Bookmarklet for Adding a cookie to your current domain

index.js

javascript: (() => {
  const COOKIE_NAME = 'FOOBAR';
  const COOKIE_VALUE = 1;
  /**
   * Should we show the alert popup after setting the cookie?
   */
  const SHOULD_ALERT = true;

  var date = new Date();
  date.setYear(date.getFullYear() + 1);
  var origHost = window.location.host;
  var domain = origHost.split('.').splice(-2).join('.');
  document.cookie = `${COOKIE_NAME}=${COOKIE_VALUE}; SameSite=None; Secure; Domain=.${domain}; Path=/; Expires=${date.toGMTString()}`;
  if (SHOULD_ALERT) {
    alert(`Set ${COOKIE_NAME} cookie`);
  }
})();