mixpanel-patch.js

// Patch the a `track` method on the mixpanel library
// This method is identical to `mixpanel.track`, but it executes the callback if mixpanel has not returned within 350ms
// Addresses an issue in the mixpanel library where the library has not been loaded (becuase of a timeout or blocked by ad blocker),
// and the initialized version is used instead. Due to a bug in the mixpanel loader, callbacks are never triggered when this occurs
var unpatchedMixpanelTrack = mixpanel.track;
mixpanel.track = function(event_name, properties, callback) {
    if(!callback) {
        return unpatchedMixpanelTrack(event_name, properties);
    } else {
        // make it 50ms over mixpanel's default 300ms callback timeout
        var callbackSafetyTimeout = setTimeout(function() { callback(); }, 350);
        unpatchedMixpanelTrack(event_name, properties, function() {
            clearTimeout(callbackSafetyTimeout);
            callback();
        });
    }
};