Check url params for XSS: window.location = 'javascript://a%0aalert%28document.cookie%29'

checkParams.js

window.location.search.substr(1).split('&').map(value => {
  return value.split('=')[1];
}).filter(value => {
  const parser = document.createElement('a');
  
  parser.href = value;
  
  return parser.protocol === "javascript:";
}).length;