Find the globals defined by the current page on window

find-defined-window-globals.js

// find the globals defined by the current page
(function(){
    var iframe = document.createElement('iframe');
    iframe.src = "about:blank";
    document.body.appendChild(iframe);

    var windowVars = Object.keys(iframe.contentWindow);
    var globalVars = Object.keys(window).filter(key => !windowVars.includes(key));

    console.log("global Vars:", globalVars);
    document.body.removeChild(iframe);
})();