firebase-messaging-sw.js

// Give the ServiceWorker access to Firebase Messaging.
// In version 9 it uses modules, so to simplify will use a 'compat' version for the ServiceWorker.
importScripts('https://www.gstatic.com/firebasejs/9.11.0/firebase-app-compat.js');
importScripts('https://www.gstatic.com/firebasejs/9.11.0/firebase-messaging-compat.js');

// Web app's Firebase configuration
const firebaseConfig = {
    apiKey: "AIzaSyD4kj2g3e_SOQTmzBUtDn2_vx6UvcdWiG8",
    authDomain: "kulikov-dev.firebaseapp.com",
    projectId: "kulikov-dev",
    storageBucket: "kulikov-dev.appspot.com",
    messagingSenderId: "441130914859",
    appId: "1:441130914859:web:2cb9c5736e4a595af0066e"
};

// Retrieve an instance of Firebase Messaging so that it can handle background messages.
firebase.initializeApp(firebaseConfig);
const messaging = firebase.messaging();

messaging.onBackgroundMessage(function (payload) {
    console.log('[firebase-messaging-sw.js] Received background message ', payload);

    // Copy data object to get parameters in the click handler
    payload.data.data = JSON.parse(JSON.stringify(payload.data));

    return self.registration.showNotification(payload.data.title, payload.data);
});

// Open/focus link in a notification message.
self.addEventListener('notificationclick', function (event) {
    const target = event.notification.data.click_action || '/';
    event.notification.close();

    event.waitUntil(clients.matchAll({
        type: 'window',
        includeUncontrolled: true
    }).then(function (clientList) {
        for (let i = 0; i < clientList.length; i++) {
            const client = clientList[i];
            if (client.url === target && 'focus' in client) {
                return client.focus();
            }
        }

        return clients.openWindow(target);
    }));
});