I am prototyping browser push notifications with FCM. I just copied the example code from the quickstart (https://github.com/firebase/quickstart-js/tree/master/messaging). Messages are recieved and displayed as they should be. But when I try to modify the message in the Service Worker (messaging.setBackgroundMessageHandler) nothing happens. The service worker is called, and if I implement an event listener in that service worker for the push notifications, it catches the event. But the method setBackgroundMessageHandler is never called. I am trying this on Chrome 54.
Any ideas what I need to do to customize the message in the service worker?
Thank you very much!
For anyone experiencing the same problem, here is the answer: https://github.com/firebase/quickstart-js/issues/71
short summary: do not include a "notification" element in your json message.