v1.0 with SW PWA enabled

frontend/node_modules/workbox-precaching/PrecacheStrategy.js

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+/*
+  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 { copyResponse } from 'workbox-core/copyResponse.js';
+import { cacheNames } from 'workbox-core/_private/cacheNames.js';
+import { getFriendlyURL } from 'workbox-core/_private/getFriendlyURL.js';
+import { logger } from 'workbox-core/_private/logger.js';
+import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
+import { Strategy } from 'workbox-strategies/Strategy.js';
+import './_version.js';
+/**
+ * A {@link workbox-strategies.Strategy} implementation
+ * specifically designed to work with
+ * {@link workbox-precaching.PrecacheController}
+ * to both cache and fetch precached assets.
+ *
+ * Note: an instance of this class is created automatically when creating a
+ * `PrecacheController`; it's generally not necessary to create this yourself.
+ *
+ * @extends workbox-strategies.Strategy
+ * @memberof workbox-precaching
+ */
+class PrecacheStrategy extends Strategy {
+    /**
+     *
+     * @param {Object} [options]
+     * @param {string} [options.cacheName] Cache name to store and retrieve
+     * requests. Defaults to the cache names provided by
+     * {@link workbox-core.cacheNames}.
+     * @param {Array<Object>} [options.plugins] {@link https://developers.google.com/web/tools/workbox/guides/using-plugins|Plugins}
+     * to use in conjunction with this caching strategy.
+     * @param {Object} [options.fetchOptions] Values passed along to the
+     * {@link https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch#Parameters|init}
+     * of all fetch() requests made by this strategy.
+     * @param {Object} [options.matchOptions] The
+     * {@link https://w3c.github.io/ServiceWorker/#dictdef-cachequeryoptions|CacheQueryOptions}
+     * for any `cache.match()` or `cache.put()` calls made by this strategy.
+     * @param {boolean} [options.fallbackToNetwork=true] Whether to attempt to
+     * get the response from the network if there's a precache miss.
+     */
+    constructor(options = {}) {
+        options.cacheName = cacheNames.getPrecacheName(options.cacheName);
+        super(options);
+        this._fallbackToNetwork =
+            options.fallbackToNetwork === false ? false : true;
+        // Redirected responses cannot be used to satisfy a navigation request, so
+        // any redirected response must be "copied" rather than cloned, so the new
+        // response doesn't contain the `redirected` flag. See:
+        // https://bugs.chromium.org/p/chromium/issues/detail?id=669363&desc=2#c1
+        this.plugins.push(PrecacheStrategy.copyRedirectedCacheableResponsesPlugin);
+    }
+    /**
+     * @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 response = await handler.cacheMatch(request);
+        if (response) {
+            return response;
+        }
+        // If this is an `install` event for an entry that isn't already cached,
+        // then populate the cache.
+        if (handler.event && handler.event.type === 'install') {
+            return await this._handleInstall(request, handler);
+        }
+        // Getting here means something went wrong. An entry that should have been
+        // precached wasn't found in the cache.
+        return await this._handleFetch(request, handler);
+    }
+    async _handleFetch(request, handler) {
+        let response;
+        const params = (handler.params || {});
+        // Fall back to the network if we're configured to do so.
+        if (this._fallbackToNetwork) {
+            if (process.env.NODE_ENV !== 'production') {
+                logger.warn(`The precached response for ` +
+                    `${getFriendlyURL(request.url)} in ${this.cacheName} was not ` +
+                    `found. Falling back to the network.`);
+            }
+            const integrityInManifest = params.integrity;
+            const integrityInRequest = request.integrity;
+            const noIntegrityConflict = !integrityInRequest || integrityInRequest === integrityInManifest;
+            // Do not add integrity if the original request is no-cors
+            // See https://github.com/GoogleChrome/workbox/issues/3096
+            response = await handler.fetch(new Request(request, {
+                integrity: request.mode !== 'no-cors'
+                    ? integrityInRequest || integrityInManifest
+                    : undefined,
+            }));
+            // It's only "safe" to repair the cache if we're using SRI to guarantee
+            // that the response matches the precache manifest's expectations,
+            // and there's either a) no integrity property in the incoming request
+            // or b) there is an integrity, and it matches the precache manifest.
+            // See https://github.com/GoogleChrome/workbox/issues/2858
+            // Also if the original request users no-cors we don't use integrity.
+            // See https://github.com/GoogleChrome/workbox/issues/3096
+            if (integrityInManifest &&
+                noIntegrityConflict &&
+                request.mode !== 'no-cors') {
+                this._useDefaultCacheabilityPluginIfNeeded();
+                const wasCached = await handler.cachePut(request, response.clone());
+                if (process.env.NODE_ENV !== 'production') {
+                    if (wasCached) {
+                        logger.log(`A response for ${getFriendlyURL(request.url)} ` +
+                            `was used to "repair" the precache.`);
+                    }
+                }
+            }
+        }
+        else {
+            // This shouldn't normally happen, but there are edge cases:
+            // https://github.com/GoogleChrome/workbox/issues/1441
+            throw new WorkboxError('missing-precache-entry', {
+                cacheName: this.cacheName,
+                url: request.url,
+            });
+        }
+        if (process.env.NODE_ENV !== 'production') {
+            const cacheKey = params.cacheKey || (await handler.getCacheKey(request, 'read'));
+            // Workbox is going to handle the route.
+            // print the routing details to the console.
+            logger.groupCollapsed(`Precaching is responding to: ` + getFriendlyURL(request.url));
+            logger.log(`Serving the precached url: ${getFriendlyURL(cacheKey instanceof Request ? cacheKey.url : cacheKey)}`);
+            logger.groupCollapsed(`View request details here.`);
+            logger.log(request);
+            logger.groupEnd();
+            logger.groupCollapsed(`View response details here.`);
+            logger.log(response);
+            logger.groupEnd();
+            logger.groupEnd();
+        }
+        return response;
+    }
+    async _handleInstall(request, handler) {
+        this._useDefaultCacheabilityPluginIfNeeded();
+        const response = await handler.fetch(request);
+        // Make sure we defer cachePut() until after we know the response
+        // should be cached; see https://github.com/GoogleChrome/workbox/issues/2737
+        const wasCached = await handler.cachePut(request, response.clone());
+        if (!wasCached) {
+            // Throwing here will lead to the `install` handler failing, which
+            // we want to do if *any* of the responses aren't safe to cache.
+            throw new WorkboxError('bad-precaching-response', {
+                url: request.url,
+                status: response.status,
+            });
+        }
+        return response;
+    }
+    /**
+     * This method is complex, as there a number of things to account for:
+     *
+     * The `plugins` array can be set at construction, and/or it might be added to
+     * to at any time before the strategy is used.
+     *
+     * At the time the strategy is used (i.e. during an `install` event), there
+     * needs to be at least one plugin that implements `cacheWillUpdate` in the
+     * array, other than `copyRedirectedCacheableResponsesPlugin`.
+     *
+     * - If this method is called and there are no suitable `cacheWillUpdate`
+     * plugins, we need to add `defaultPrecacheCacheabilityPlugin`.
+     *
+     * - If this method is called and there is exactly one `cacheWillUpdate`, then
+     * we don't have to do anything (this might be a previously added
+     * `defaultPrecacheCacheabilityPlugin`, or it might be a custom plugin).
+     *
+     * - If this method is called and there is more than one `cacheWillUpdate`,
+     * then we need to check if one is `defaultPrecacheCacheabilityPlugin`. If so,
+     * we need to remove it. (This situation is unlikely, but it could happen if
+     * the strategy is used multiple times, the first without a `cacheWillUpdate`,
+     * and then later on after manually adding a custom `cacheWillUpdate`.)
+     *
+     * See https://github.com/GoogleChrome/workbox/issues/2737 for more context.
+     *
+     * @private
+     */
+    _useDefaultCacheabilityPluginIfNeeded() {
+        let defaultPluginIndex = null;
+        let cacheWillUpdatePluginCount = 0;
+        for (const [index, plugin] of this.plugins.entries()) {
+            // Ignore the copy redirected plugin when determining what to do.
+            if (plugin === PrecacheStrategy.copyRedirectedCacheableResponsesPlugin) {
+                continue;
+            }
+            // Save the default plugin's index, in case it needs to be removed.
+            if (plugin === PrecacheStrategy.defaultPrecacheCacheabilityPlugin) {
+                defaultPluginIndex = index;
+            }
+            if (plugin.cacheWillUpdate) {
+                cacheWillUpdatePluginCount++;
+            }
+        }
+        if (cacheWillUpdatePluginCount === 0) {
+            this.plugins.push(PrecacheStrategy.defaultPrecacheCacheabilityPlugin);
+        }
+        else if (cacheWillUpdatePluginCount > 1 && defaultPluginIndex !== null) {
+            // Only remove the default plugin; multiple custom plugins are allowed.
+            this.plugins.splice(defaultPluginIndex, 1);
+        }
+        // Nothing needs to be done if cacheWillUpdatePluginCount is 1
+    }
+}
+PrecacheStrategy.defaultPrecacheCacheabilityPlugin = {
+    async cacheWillUpdate({ response }) {
+        if (!response || response.status >= 400) {
+            return null;
+        }
+        return response;
+    },
+};
+PrecacheStrategy.copyRedirectedCacheableResponsesPlugin = {
+    async cacheWillUpdate({ response }) {
+        return response.redirected ? await copyResponse(response) : response;
+    },
+};
+export { PrecacheStrategy };