add service worker versioning

src/component/version/index.js

@@ -1,38 +1,36 @@
-export const version = {};
+export const version = {
+  number: '7.5.0',
+  name: 'Delightful Komodo Dragon',
+  compare: (a, b) => {
 
-version.number = '7.5.0';
+    let pa = a.split('.');
 
-version.name = 'Delightful Komodo Dragon';
+    let pb = b.split('.');
 
-version.compare = (a, b) => {
+    for (let i = 0; i < 3; i++) {
 
-  let pa = a.split('.');
+      let na = Number(pa[i]);
 
-  let pb = b.split('.');
+      let nb = Number(pb[i]);
 
-  for (let i = 0; i < 3; i++) {
+      if (na > nb) {
+        return 1;
+      }
 
-    let na = Number(pa[i]);
+      if (nb > na) {
+        return -1;
+      }
 
-    let nb = Number(pb[i]);
+      if (!isNaN(na) && isNaN(nb)) {
+        return 1;
+      }
 
-    if (na > nb) {
-      return 1;
-    }
-
-    if (nb > na) {
-      return -1;
-    }
+      if (isNaN(na) && !isNaN(nb)) {
+        return -1;
+      }
 
-    if (!isNaN(na) && isNaN(nb)) {
-      return 1;
-    }
-
-    if (isNaN(na) && !isNaN(nb)) {
-      return -1;
     }
 
+    return 0;
   }
-
-  return 0;
 };

src/serviceWorker/service_worker.js

@@ -1,12 +1,15 @@
 import { policies } from './policies';
 import {APP_NAME} from '../constant';
 
+import { version } from '../component/version';
+
+const CACHE_NAME = `${APP_NAME}-${version.number}`;
+
 self.addEventListener('install', event => { // register
   console.log('serviceWorker installing...');
   event.waitUntil(async () => {
 
-    await caches.delete(APP_NAME); // clear old cache
-    await caches.open(APP_NAME).then( cache => {
+    await caches.open(CACHE_NAME).then( cache => {
       // check if running in chrome extension
       if(chrome?.extension) {
         console.log('running in chrome extension, nothing to cache');
@@ -30,5 +33,27 @@ self.addEventListener('fetch', event => { // intercept
   let policy = policies.find(
     pattern => pattern.url.test(event.request.url)
   );
-  event.respondWith(policy.handle(APP_NAME, event));
+  event.respondWith(policy.handle(CACHE_NAME, event));
+});
+
+// Delete outdated caches
+self.addEventListener('activate', function (e) {
+  e.waitUntil(
+    caches.keys().then(function (keyList) {
+      // filter out all caches that are not part of this app
+      let cacheWhitelist = keyList.filter(function (key) {
+        return key.indexOf(APP_NAME);
+      });
+      // add current latest cache to whitelist
+      cacheWhitelist.push(CACHE_NAME);
+
+      return Promise.all(keyList.map(function (key, i) {
+        if (cacheWhitelist.indexOf(key) === -1) {
+          console.log('deleting cache : ' + keyList[i]);
+          return caches.delete(keyList[i]);
+        }
+      }));
+    })
+  );
+  console.log('serviceWorker version ' + version.number + ' activated');
 });