Remap Events Event Time Parameter as an Event Parameter

GA4_eventTimeRemap.js

(function() {
    /*
    *  
    * ( David Vallejo @thyng )
    * MIT  License
    * Remap _et ( Event Time ) as a customEvent Perameter    
    * 
    */
    try {
        // Monkey Patch, sendBeacon 
        var proxied = window.navigator.sendBeacon;
        var remapEventTime = (payload)=> {
            // object.entries polyfill
            // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries#Polyfill
            if (!Object.entries)
                Object.entries = function(obj) {
                    var ownProps = Object.keys(obj)
                      , i = ownProps.length
                      , resArray = new Array(i);
                    // preallocate the Array            
                    while (i--)
                        resArray[i] = [ownProps[i], obj[ownProps[i]]];
                    return resArray;
                }
                ;

            var eventPayload = payload.replace(/(^\?)/, '').split("&").map(function(n) {
                return n = n.split("="),
                this[n[0]] = decodeURIComponent(n[1]),
                this;
            }
            .bind({}))[0];

            if (eventPayload._et)
                eventPayload["epn.event_time"] = eventPayload._et

            return Object.keys(eventPayload).map(function(key) {
                return (key) + '=' + encodeURIComponent(eventPayload[key]);
            }).join('&');
        }

        window.navigator.sendBeacon = function() {
            if (arguments && arguments[0].match(/google-analytics\.com.*v\=2\&/)) {

                var endpoint = arguments[0].split('?')[0];
                var query = arguments[0].split('?')[1];
                var beacon = {
                    endpoint: endpoint,
                    // Check for PII
                    query: remapEventTime(query),
                    events: []
                };
                // This is a multiple events hit
                if (arguments[1]) {
                    arguments[1].split("\r\n").forEach(function(event) {
                        beacon.events.push(remapEventTime(event));
                    });
                }

                // We're all done, let's reassamble everything
                arguments[0] = [beacon.endpoint, beacon.query].join('?');
                if (arguments[1] && beacon.events.length > 0) {
                    arguments[1] = beacon.events.join("\r\n");
                }
            }
            return proxied.apply(this, arguments);
        }
        ;
    } catch (e) {
        // In case something goes wrong, let's apply back the arguments to the original function
        return proxied.apply(this, arguments);
    }
}
)();