self.addEventListener("install", function (event) { event.waitUntil( caches.open("cache").then(function (cache) { var synth = new Response( '', { headers: { "Content-Type": "text/html" } } ); return Promise.all([ cache.add("index.html"), cache.put("synth-sw.html", synth), ]); }) ); }); self.addEventListener("fetch", function (event) { if (event.request.url.includes("index.html")) { event.respondWith(caches.match(event.request)); } else if (event.request.url.includes("synth-sw.html")) { event.respondWith(caches.match(event.request)); } else if (event.request.url.includes("synth-window.html")) { event.respondWith(caches.match(event.request)); } else if (event.request.url.includes("synth.html")) { event.respondWith( new Response( '', { headers: { "Content-Type": "text/html" } } ) ); } });