generate a service worker

npm install workbox-cli
./node_modules/.bin/workbox injectManifest workbox-config.js

service worker: ignore query string for fonts

The compilation was run with 'ASSET_PATH="dist/" make'. This is needed
for officejs app because the HTML is not at the root of the domain
(https://converse.app.officejs.com/563950fb93/fullscreen.html).

fullscreen.html

@@ -47,6 +47,10 @@
     For more information, please refer to <http://unlicense.org/>
     @licend
     */
+    window.addEventListener('load', () => {
+         navigator.serviceWorker.register('sw.js');
+    });
+
     converse.initialize({
         authentication: 'login',
         auto_away: 300,

sw.template.js

+importScripts('https://storage.googleapis.com/workbox-cdn/releases/5.1.4/workbox-sw.js');
+
+workbox.core.setCacheNameDetails({
+  prefix: 'converse.nexedi',
+});
+
+// Note: this is populated at build time.
+workbox.precaching.precacheAndRoute(self.__WB_MANIFEST,
+  // we ignore wvi0ht for urls like :
+  //  /fonticons/fonts/icomoon.ttf?wvi0ht
+  { ignoreUrlParametersMatching: [/^wvi0ht/] }
+)
+

workbox-config.js

+module.exports = {
+  globDirectory: '.',
+  globPatterns: [
+    '*.html',
+    'manifest.json',
+    'dist/**',
+    'css/**',
+    'locale/**',
+    'sounds/**',
+    'logo/**',
+  ],
+  swSrc: 'sw.template.js',
+  swDest: 'sw.js',
+  maximumFileSizeToCacheInBytes: 1024**4
+};