"ReferenceError: Notification is not defined" on Firefox when notifications are disabled

[marauder37]

If a Firefox user has disabled notifications globally by setting dom.webnotifications.enabled:false in prefs (like me!), there will be no Notification object. webpush.js needs to check whether it exists before trying to test its properties.

See also https://miketaylr.com/posts/2017/02/how-not-to-feature-detect.html which helped me work out the problem after a lot of searching. I had forgotten that I disabled notifications.

Thanks!

[safwanrahman]

Thanks a lot @marauder37 for the issue! I did not know about it!
I will try to fix the issue soon!