self.addEventListener('install', () => self.skipWaiting());
self.addEventListener('activate', e => {
  e.waitUntil((async () => {
    await self.clients.claim();
    const keys = await caches.keys();
    await Promise.all(keys.map(k => caches.delete(k)));
    const all = await self.clients.matchAll({ type: 'window', includeUncontrolled: true });
    for (const c of all) c.navigate(c.url);
    await self.registration.unregister();
  })());
});