attempt to recursively hook iframe postMessages (doesn't work due to browser security policies)

hookAll.js

((() => {
console.log("postMessage hook added");
new MutationObserver((mutations, observer) => {
const flatten = (a,c) => a.concat(c);
const allNodes =  mutations.filter(({ type }) => type == "childList")
    .map(({ addedNodes }) => Array.from(addedNodes)).reduce(flatten, []);
  
allNodes
  .forEach(parentNode => {
    if (!parentNode.getElementsByTagName) return;
    [...parentNode.getElementsByTagName("iframe")].forEach(iframe => {
      let x = iframe.contentWindow.postMessage;
      console.log("hooked", iframe);
      iframe.contentWindow.postMessage = function(...a) {
        console.log(`SEND to`, iframe, `${a}`);
        x.apply(iframe, [...a]);
      }
    })
  })
  
  
}).observe(document.documentElement, {childList: true, subtree: true });

window.addEventListener("message", e => console.log(`RCV from`, e.origin, {...e}))
})(),false);