XOR encrypt-decrypt location hash

hash-crypt.js

((w) => {

  function superpooper(secret) {
    const pass = encodeURIComponent(secret);
    return function onHashChange(){
      var hash = w.location.hash.replace(/^#/,"");
      if (!hash.length) return;
      
      const xor = s => s.split('').map((c,i)=>String.fromCharCode(c.charCodeAt(0)^pass.charCodeAt(i%pass.length))).join('');
  
      if (hash[0]==='!') {
        hash = hash.substring(1);
        const decoded = decodeURIComponent(xor(atob(hash)));
        history.replaceState(null, null, document.location.pathname + '#' + decoded);
      } else {
        const encoded = btoa(xor(encodeURIComponent(hash)));
        history.replaceState(null, null, document.location.pathname + '#!' + encoded);
      }
    }
  }

  w.addEventListener("hashchange", superpooper("abrakadabra"), false);
  
})(window)