Log messages sent/received

post-message-logger.js

window.addEventListener('message', function MessageLogger (o) {
    console.debug('Message Origin:%s Data:%o', o.origin, o.data);
});

window.__postMessage = Window.prototype.postMessage;
Window.prototype.postMessage = function _postMessage () {
    console.debug('PostMessage %o', Array.from(arguments));
    window.__postMessage.apply(this, arguments);
};