No errors received for unregistered/ invalid tokens

[JaneDawson]

I use the cordova-plugin-fcm for my Ionic 3 app. Thank you for this great plugin.

However, I'm experiencing the following issue and hope you can help figuring out how to solve it. Whenever a user logs in, I store the device token in my database using FCMPlugin.getToken(). When he logs out, I delete the token from my database. When a user logs in and then decides to uninstall the app without logging out first, I don't know about the uninstallation and still have the (invalid) token in my database.

When I send a push notification to this invalid device token using Firebase's sendToDevice() function, I expect to get an error like the firebase error messaging/registration-token-not-registered (see here). However, there is no error returned at all, even if the app was uninstall more than a day ago.

How can I receive error messages to know that the token is invalid?

[blumanski]

What is the catch error coming up with? You use node I guess... https://firebase.google.com/docs/cloud-messaging/admin/send-messages

admin.messaging().sendToDevice(registrationToken, payload)
.then(){

})
.catch(error) {
    console.log(error)
}

Another thing, you may not delete the token ever but update it onTokenRefresh, code i use in a ionic 1 app.

FCMPlugin.onTokenRefresh(function(token){
        $scope.Token = token;
        $scope.clickedSubscribe();
 });

[JaneDawson]

1) Unfortunately, the .catch is not coming up with anything. As I said, there is no error returned at all.

2) I'm using onTokenRefresh.as well. However, I decided to delete the token on logout, since then my app knows if any user is currently signed on with at least one device (1+ device tokens in DB) or not (no device token in DB). If user is not signed on at all, I don't want to send him push notifications.

[JaneDawson]

Nobady an idea? Shouldn't I receive an error in case the app was uninstalled by the user (as it's suggested by firebase)?