v1.0 with SW PWA enabled

frontend/node_modules/workbox-strategies/src/plugins/cacheOkAndOpaquePlugin.ts

@@ -0,0 +1,29 @@
+/*
+  Copyright 2018 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 {WorkboxPlugin} from 'workbox-core/types.js';
+import '../_version.js';
+
+export const cacheOkAndOpaquePlugin: WorkboxPlugin = {
+  /**
+   * Returns a valid response (to allow caching) if the status is 200 (OK) or
+   * 0 (opaque).
+   *
+   * @param {Object} options
+   * @param {Response} options.response
+   * @return {Response|null}
+   *
+   * @private
+   */
+  cacheWillUpdate: async ({response}) => {
+    if (response.status === 200 || response.status === 0) {
+      return response;
+    }
+    return null;
+  },
+};