url-search-params.user.js

// ==UserScript==
// @name     URLSearchParams test
// @version  1
// @grant    none
// ==/UserScript==

// Test for https://github.com/greasemonkey/greasemonkey/issues/3136

const searchParams = new URLSearchParams("key1=value1&key2=value2");
for (const key of searchParams.keys()) {
  console.log(key);
}