Firebase web push notifications show up twice - firebase-cloud-messaging

Question

Using firebase-messaging.js v8.2.0 and using onBackgroundMessage to show notification, the notification is being sent 2 times, the default one and the onBackgroundMessage one.
What are your thoughts abou this problem? Code is same as documented in the firebase mesaging quickstart sample

Answer 1

I changed one of firebase notification scripts code. There was an unexpected bug which is sending the notification two times. I can send you the files. Meanwhile, this is my firebase-messaging.sw.js (I hided the keys).
importScripts("https://www.gstatic.com/firebasejs/8.2.0/firebase-app.js");
importScripts("firebase-messaging.js");
/*
Initialize the Firebase app in the service worker by passing in the messagingSenderId.
* New configuration for app#pulseservice.com
*/
firebase.initializeApp({
apiKey: "",
authDomain: "",
databaseURL: "",
projectId: "",
storageBucket: "",
messagingSenderId: "",
appId: "",
measurementId: ""
});
const messaging = firebase.messaging();
messaging.onBackgroundMessage(function (payload) {
console.log("[firebase-messaging-sw.js] Received background message ", payload);
// Customize notification here
let url = payload.data.notification_url;
const notificationTitle1 = payload.notification.title;
const notificationOptions1 = {
body: payload.notification.body,
icon: "",
data: { url: payload.data.notification_url },
image: payload.notification.image
};
return self.registration.showNotification(notificationTitle1, notificationOptions1);
});
self.addEventListener("notificationclick", function (event) {
let url = event.notification.data.url;
event.notification.close();
event.waitUntil(
clients.matchAll({ type: "window" }).then(windowClients => {
// Check if there is already a window/tab open with the target URL
for (var i = 0; i < windowClients.length; i++) {
var client = windowClients[i];
// If so, just focus it.
if (client.url === url && "focus" in client) {
return client.focus();
}
}
// If not, then open the target URL in a new window/tab.
if (clients.openWindow) {
return clients.openWindow(url);
}
})
);
});
The file I changed is firebase-messaging.js and saved it into the sites static files with the changes I made. Let me know if you need it.