sw.js

self.addEventListener('push', (event) => {
    if (!(self.Notification && self.Notification.permission === 'granted')) {
        return;
    }

    let data = {};
    if (event.data) {
        data = event.data.json();
    }
    const title = data.title;
    const message = data.message;

    self.clickTarget = data.clickTarget;

    event.waitUntil(self.registration.showNotification(title, {
        body: message,
        tag: 'schnack'
    }));
});

self.addEventListener('notificationclick', (event) => {
    event.notification.close();

    if(clients.openWindow){
        event.waitUntil(clients.openWindow(self.clickTarget));
    }
});