v1.0 with SW PWA enabled

frontend/node_modules/workbox-recipes/src/offlineFallback.ts

@@ -0,0 +1,87 @@
+/*
+  Copyright 2020 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import {setCatchHandler} from 'workbox-routing/setCatchHandler.js';
+import {matchPrecache} from 'workbox-precaching/matchPrecache.js';
+import {RouteHandler, RouteHandlerCallbackOptions} from 'workbox-core/types.js';
+
+import './_version.js';
+
+export interface OfflineFallbackOptions {
+  pageFallback?: string;
+  imageFallback?: string;
+  fontFallback?: string;
+}
+
+// Give TypeScript the correct global.
+declare let self: ServiceWorkerGlobalScope;
+
+/**
+ * An implementation of the [comprehensive fallbacks recipe]{@link https://developers.google.com/web/tools/workbox/guides/advanced-recipes#comprehensive_fallbacks}. Be sure to include the fallbacks in your precache injection
+ *
+ * @memberof workbox-recipes
+ *
+ * @param {Object} [options]
+ * @param {string} [options.pageFallback] Precache name to match for pag fallbacks. Defaults to offline.html
+ * @param {string} [options.imageFallback] Precache name to match for image fallbacks.
+ * @param {string} [options.fontFallback] Precache name to match for font fallbacks.
+ */
+function offlineFallback(options: OfflineFallbackOptions = {}): void {
+  const pageFallback = options.pageFallback || 'offline.html';
+  const imageFallback = options.imageFallback || false;
+  const fontFallback = options.fontFallback || false;
+
+  self.addEventListener('install', (event) => {
+    const files = [pageFallback];
+    if (imageFallback) {
+      files.push(imageFallback);
+    }
+    if (fontFallback) {
+      files.push(fontFallback);
+    }
+
+    event.waitUntil(
+      self.caches
+        .open('workbox-offline-fallbacks')
+        .then((cache) => cache.addAll(files)),
+    );
+  });
+
+  const handler: RouteHandler = async (
+    options: RouteHandlerCallbackOptions,
+  ) => {
+    const dest = options.request.destination;
+    const cache = await self.caches.open('workbox-offline-fallbacks');
+
+    if (dest === 'document') {
+      const match =
+        (await matchPrecache(pageFallback)) ||
+        (await cache.match(pageFallback));
+      return match || Response.error();
+    }
+
+    if (dest === 'image' && imageFallback !== false) {
+      const match =
+        (await matchPrecache(imageFallback)) ||
+        (await cache.match(imageFallback));
+      return match || Response.error();
+    }
+
+    if (dest === 'font' && fontFallback !== false) {
+      const match =
+        (await matchPrecache(fontFallback)) ||
+        (await cache.match(fontFallback));
+      return match || Response.error();
+    }
+
+    return Response.error();
+  };
+
+  setCatchHandler(handler);
+}
+
+export {offlineFallback};