v1.0 with SW PWA enabled

frontend/node_modules/workbox-strategies/StaleWhileRevalidate.js

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+/*
+  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 { assert } from 'workbox-core/_private/assert.js';
+import { logger } from 'workbox-core/_private/logger.js';
+import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
+import { cacheOkAndOpaquePlugin } from './plugins/cacheOkAndOpaquePlugin.js';
+import { Strategy } from './Strategy.js';
+import { messages } from './utils/messages.js';
+import './_version.js';
+/**
+ * An implementation of a
+ * [stale-while-revalidate](https://developer.chrome.com/docs/workbox/caching-strategies-overview/#stale-while-revalidate)
+ * request strategy.
+ *
+ * Resources are requested from both the cache and the network in parallel.
+ * The strategy will respond with the cached version if available, otherwise
+ * wait for the network response. The cache is updated with the network response
+ * with each successful request.
+ *
+ * By default, this strategy will cache responses with a 200 status code as
+ * well as [opaque responses](https://developer.chrome.com/docs/workbox/caching-resources-during-runtime/#opaque-responses).
+ * Opaque responses are cross-origin requests where the response doesn't
+ * support [CORS](https://enable-cors.org/).
+ *
+ * If the network request fails, and there is no cache match, this will throw
+ * a `WorkboxError` exception.
+ *
+ * @extends workbox-strategies.Strategy
+ * @memberof workbox-strategies
+ */
+class StaleWhileRevalidate extends Strategy {
+    /**
+     * @param {Object} [options]
+     * @param {string} [options.cacheName] Cache name to store and retrieve
+     * requests. Defaults to cache names provided by
+     * {@link workbox-core.cacheNames}.
+     * @param {Array<Object>} [options.plugins] [Plugins]{@link https://developers.google.com/web/tools/workbox/guides/using-plugins}
+     * to use in conjunction with this caching strategy.
+     * @param {Object} [options.fetchOptions] Values passed along to the
+     * [`init`](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#Parameters)
+     * of [non-navigation](https://github.com/GoogleChrome/workbox/issues/1796)
+     * `fetch()` requests made by this strategy.
+     * @param {Object} [options.matchOptions] [`CacheQueryOptions`](https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions)
+     */
+    constructor(options = {}) {
+        super(options);
+        // If this instance contains no plugins with a 'cacheWillUpdate' callback,
+        // prepend the `cacheOkAndOpaquePlugin` plugin to the plugins list.
+        if (!this.plugins.some((p) => 'cacheWillUpdate' in p)) {
+            this.plugins.unshift(cacheOkAndOpaquePlugin);
+        }
+    }
+    /**
+     * @private
+     * @param {Request|string} request A request to run this strategy for.
+     * @param {workbox-strategies.StrategyHandler} handler The event that
+     *     triggered the request.
+     * @return {Promise<Response>}
+     */
+    async _handle(request, handler) {
+        const logs = [];
+        if (process.env.NODE_ENV !== 'production') {
+            assert.isInstance(request, Request, {
+                moduleName: 'workbox-strategies',
+                className: this.constructor.name,
+                funcName: 'handle',
+                paramName: 'request',
+            });
+        }
+        const fetchAndCachePromise = handler.fetchAndCachePut(request).catch(() => {
+            // Swallow this error because a 'no-response' error will be thrown in
+            // main handler return flow. This will be in the `waitUntil()` flow.
+        });
+        void handler.waitUntil(fetchAndCachePromise);
+        let response = await handler.cacheMatch(request);
+        let error;
+        if (response) {
+            if (process.env.NODE_ENV !== 'production') {
+                logs.push(`Found a cached response in the '${this.cacheName}'` +
+                    ` cache. Will update with the network response in the background.`);
+            }
+        }
+        else {
+            if (process.env.NODE_ENV !== 'production') {
+                logs.push(`No response found in the '${this.cacheName}' cache. ` +
+                    `Will wait for the network response.`);
+            }
+            try {
+                // NOTE(philipwalton): Really annoying that we have to type cast here.
+                // https://github.com/microsoft/TypeScript/issues/20006
+                response = (await fetchAndCachePromise);
+            }
+            catch (err) {
+                if (err instanceof Error) {
+                    error = err;
+                }
+            }
+        }
+        if (process.env.NODE_ENV !== 'production') {
+            logger.groupCollapsed(messages.strategyStart(this.constructor.name, request));
+            for (const log of logs) {
+                logger.log(log);
+            }
+            messages.printFinalResponse(response);
+            logger.groupEnd();
+        }
+        if (!response) {
+            throw new WorkboxError('no-response', { url: request.url, error });
+        }
+        return response;
+    }
+}
+export { StaleWhileRevalidate };