monaco-editor/website/public/sw.js

const CACHE = 'switch-cache-v1';
const ASSETS = [
  '/',
  '/index.html',
  '/playground.html',
  '/monarch.html',
  '/switch.html'
];
self.addEventListener('install', (e) => {
  e.waitUntil(caches.open(CACHE).then(c=>c.addAll(ASSETS)).then(()=>self.skipWaiting()));
});
self.addEventListener('activate', (e) => {
  e.waitUntil(caches.keys().then(keys=>Promise.all(keys.filter(k=>k!==CACHE).map(k=>caches.delete(k)))).then(()=>self.clients.claim()));
});
self.addEventListener('fetch', (e) => {
  const url = new URL(e.request.url);
  if (url.origin === location.origin) {
    e.respondWith(caches.match(e.request).then(r=> r || fetch(e.request).then(resp=>{
      if (e.request.method==='GET' && resp.ok && resp.type==='basic') {
        const clone = resp.clone();
        caches.open(CACHE).then(c=>c.put(e.request, clone));
      }
      return resp;
    }).catch(()=>caches.match('/index.html'))));
  }
});