add primitive cache busting, update service worker

lib/public/scripts.js

@@ -223,9 +223,29 @@
       setTimeout(() => {
         setServiceWorkerStatus('')
       }, 4500)
+
+      registration.addEventListener('updatefound', () => {
+        console.info('Service worker will be updated...')
+        const newWorker = registration.installing
+
+        newWorker.addEventListener('statechange', () => {
+          if (newWorker.state === 'installed') {
+            newWorker.postMessage({ action: 'skipWaiting' })
+          }
+        })
+      })
     }).catch((err) => {
       setServiceWorkerStatus(`Service worker error: ${err.toString()}`)
     })
+
+    let refreshing
+    serviceWorker.addEventListener('controllerchange', () => {
+      if (refreshing) {
+        return
+      }
+      window.location.reload()
+      refreshing = true
+    })
   }
 
   if (!noJS()) {

lib/public/service-worker.js

@@ -1,9 +1,13 @@
+// Worker v1
+
 self.addEventListener('install', (event) => {
   event.waitUntil(
     caches.open('fb-to-ical').then((cache) => {
       return cache.addAll([
         '/',
         '/favicon.ico',
+        '/scripts.js?1',
+        '/style.css?1',
       ])
     })
   )
@@ -17,3 +21,9 @@ self.addEventListener('fetch', (event) => {
       })
   )
 })
+
+self.addEventListener('message', (event) => {
+  if (event.data.action === 'skipWaiting') {
+    self.skipWaiting()
+  }
+})

lib/views/index.ejs

@@ -5,7 +5,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <link rel="manifest" href="/manifest.json">
     <link rel="apple-touch-icon" sizes="180x180" href="/icon-180.png">
-    <link rel="stylesheet" type="text/css" href="/style.css">
+    <link rel="stylesheet" type="text/css" href="/style.css?1">
     <title>Facebook Event to iCal Converter</title>
   </head>
 
@@ -71,6 +71,6 @@
       Created by <a href="http://ondrejsynacek.com">Ondrej Synacek</a>
     </footer>
 
-    <script src="/scripts.js"></script>
+    <script src="/scripts.js?1"></script>
   </body>
 </html>