xs-search library:

for more check xsleaks' git :)


// utils.js function receiveMessage() { return new Promise(r => { window.onmessage = r; }); } async function tick() { window.postMessage(0,'*'); return await receiveMessage(); } async function isCrossOrigin(ref) { await tick(); // skip task (responsive) try { ref.URL; // access cross-origin property return false; } catch(e) { return true; } }