Watch for closed Google Sign In oauth window

google-sign-in-window-onclose.js

/*
 * This is a snippet used to track Google Sign In oauth window
 * Based on this comment https://github.com/google/google-api-javascript-client/issues/25#issuecomment-76695596
 * You can wrap this into function to use promises, timeouts etc
 * Shame on you, Google!
 */

// Get current open function
var winOpen = window.open;
// Regexp to valiate if it is really Googe Oauth page
var googleRegex = /^.*(google\.com).*(oauth).*$/i;

window.open = function(){

    if (!googleRegex.test(arguments[0])) {
        winOpen.apply(this, arguments);
        return;
    }

    // Return stock open function
    window.open = winOpen;

    // Get Google window
    var googWndw = winOpen.apply(this, arguments);
    // Check if it is closed periodically
    var interval = setInterval(function(){

        if (!googWndw.closed) {
            return;
        }
        
        clearInterval(interval);
        interval = undefined;
        googWndw = undefined;

        console.log('google window was closed!')
    }, 1000);
};