PrecacheController.ts 12 KB
/*
  Copyright 2019 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 {cacheNames} from 'workbox-core/_private/cacheNames.js';
import {logger} from 'workbox-core/_private/logger.js';
import {WorkboxError} from 'workbox-core/_private/WorkboxError.js';
import {waitUntil} from 'workbox-core/_private/waitUntil.js';
import {Strategy} from 'workbox-strategies/Strategy.js';
import {RouteHandlerCallback, WorkboxPlugin} from 'workbox-core/types.js';

import {createCacheKey} from './utils/createCacheKey.js';
import {PrecacheInstallReportPlugin} from './utils/PrecacheInstallReportPlugin.js';
import {PrecacheCacheKeyPlugin} from './utils/PrecacheCacheKeyPlugin.js';
import {printCleanupDetails} from './utils/printCleanupDetails.js';
import {printInstallDetails} from './utils/printInstallDetails.js';
import {PrecacheStrategy} from './PrecacheStrategy.js';
import {PrecacheEntry, InstallResult, CleanupResult} from './_types.js';
import './_version.js';

// Give TypeScript the correct global.
declare let self: ServiceWorkerGlobalScope;

declare global {
  interface ServiceWorkerGlobalScope {
    __WB_MANIFEST: Array<PrecacheEntry | string>;
  }
}

interface PrecacheControllerOptions {
  cacheName?: string;
  plugins?: WorkboxPlugin[];
  fallbackToNetwork?: boolean;
}

/**
 * Performs efficient precaching of assets.
 *
 * @memberof workbox-precaching
 */
class PrecacheController {
  private _installAndActiveListenersAdded?: boolean;
  private readonly _strategy: Strategy;
  private readonly _urlsToCacheKeys: Map<string, string> = new Map();
  private readonly _urlsToCacheModes: Map<
    string,
    | 'reload'
    | 'default'
    | 'no-store'
    | 'no-cache'
    | 'force-cache'
    | 'only-if-cached'
  > = new Map();
  private readonly _cacheKeysToIntegrities: Map<string, string> = new Map();

  /**
   * Create a new PrecacheController.
   *
   * @param {Object} [options]
   * @param {string} [options.cacheName] The cache to use for precaching.
   * @param {string} [options.plugins] Plugins to use when precaching as well
   * as responding to fetch events for precached assets.
   * @param {boolean} [options.fallbackToNetwork=true] Whether to attempt to
   * get the response from the network if there's a precache miss.
   */
  constructor({
    cacheName,
    plugins = [],
    fallbackToNetwork = true,
  }: PrecacheControllerOptions = {}) {
    this._strategy = new PrecacheStrategy({
      cacheName: cacheNames.getPrecacheName(cacheName),
      plugins: [
        ...plugins,
        new PrecacheCacheKeyPlugin({precacheController: this}),
      ],
      fallbackToNetwork,
    });

    // Bind the install and activate methods to the instance.
    this.install = this.install.bind(this);
    this.activate = this.activate.bind(this);
  }

  /**
   * @type {workbox-precaching.PrecacheStrategy} The strategy created by this controller and
   * used to cache assets and respond to fetch events.
   */
  get strategy(): Strategy {
    return this._strategy;
  }

  /**
   * Adds items to the precache list, removing any duplicates and
   * stores the files in the
   * {@link workbox-core.cacheNames|"precache cache"} when the service
   * worker installs.
   *
   * This method can be called multiple times.
   *
   * @param {Array<Object|string>} [entries=[]] Array of entries to precache.
   */
  precache(entries: Array<PrecacheEntry | string>): void {
    this.addToCacheList(entries);

    if (!this._installAndActiveListenersAdded) {
      self.addEventListener('install', this.install);
      self.addEventListener('activate', this.activate);
      this._installAndActiveListenersAdded = true;
    }
  }

  /**
   * This method will add items to the precache list, removing duplicates
   * and ensuring the information is valid.
   *
   * @param {Array<workbox-precaching.PrecacheController.PrecacheEntry|string>} entries
   *     Array of entries to precache.
   */
  addToCacheList(entries: Array<PrecacheEntry | string>): void {
    if (process.env.NODE_ENV !== 'production') {
      assert!.isArray(entries, {
        moduleName: 'workbox-precaching',
        className: 'PrecacheController',
        funcName: 'addToCacheList',
        paramName: 'entries',
      });
    }

    const urlsToWarnAbout: string[] = [];
    for (const entry of entries) {
      // See https://github.com/GoogleChrome/workbox/issues/2259
      if (typeof entry === 'string') {
        urlsToWarnAbout.push(entry);
      } else if (entry && entry.revision === undefined) {
        urlsToWarnAbout.push(entry.url);
      }

      const {cacheKey, url} = createCacheKey(entry);
      const cacheMode =
        typeof entry !== 'string' && entry.revision ? 'reload' : 'default';

      if (
        this._urlsToCacheKeys.has(url) &&
        this._urlsToCacheKeys.get(url) !== cacheKey
      ) {
        throw new WorkboxError('add-to-cache-list-conflicting-entries', {
          firstEntry: this._urlsToCacheKeys.get(url),
          secondEntry: cacheKey,
        });
      }

      if (typeof entry !== 'string' && entry.integrity) {
        if (
          this._cacheKeysToIntegrities.has(cacheKey) &&
          this._cacheKeysToIntegrities.get(cacheKey) !== entry.integrity
        ) {
          throw new WorkboxError('add-to-cache-list-conflicting-integrities', {
            url,
          });
        }
        this._cacheKeysToIntegrities.set(cacheKey, entry.integrity);
      }

      this._urlsToCacheKeys.set(url, cacheKey);
      this._urlsToCacheModes.set(url, cacheMode);

      if (urlsToWarnAbout.length > 0) {
        const warningMessage =
          `Workbox is precaching URLs without revision ` +
          `info: ${urlsToWarnAbout.join(', ')}\nThis is generally NOT safe. ` +
          `Learn more at https://bit.ly/wb-precache`;
        if (process.env.NODE_ENV === 'production') {
          // Use console directly to display this warning without bloating
          // bundle sizes by pulling in all of the logger codebase in prod.
          console.warn(warningMessage);
        } else {
          logger.warn(warningMessage);
        }
      }
    }
  }

  /**
   * Precaches new and updated assets. Call this method from the service worker
   * install event.
   *
   * Note: this method calls `event.waitUntil()` for you, so you do not need
   * to call it yourself in your event handlers.
   *
   * @param {ExtendableEvent} event
   * @return {Promise<workbox-precaching.InstallResult>}
   */
  install(event: ExtendableEvent): Promise<InstallResult> {
    // waitUntil returns Promise<any>
    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
    return waitUntil(event, async () => {
      const installReportPlugin = new PrecacheInstallReportPlugin();
      this.strategy.plugins.push(installReportPlugin);

      // Cache entries one at a time.
      // See https://github.com/GoogleChrome/workbox/issues/2528
      for (const [url, cacheKey] of this._urlsToCacheKeys) {
        const integrity = this._cacheKeysToIntegrities.get(cacheKey);
        const cacheMode = this._urlsToCacheModes.get(url);

        const request = new Request(url, {
          integrity,
          cache: cacheMode,
          credentials: 'same-origin',
        });

        await Promise.all(
          this.strategy.handleAll({
            params: {cacheKey},
            request,
            event,
          }),
        );
      }

      const {updatedURLs, notUpdatedURLs} = installReportPlugin;

      if (process.env.NODE_ENV !== 'production') {
        printInstallDetails(updatedURLs, notUpdatedURLs);
      }

      return {updatedURLs, notUpdatedURLs};
    });
  }

  /**
   * Deletes assets that are no longer present in the current precache manifest.
   * Call this method from the service worker activate event.
   *
   * Note: this method calls `event.waitUntil()` for you, so you do not need
   * to call it yourself in your event handlers.
   *
   * @param {ExtendableEvent} event
   * @return {Promise<workbox-precaching.CleanupResult>}
   */
  activate(event: ExtendableEvent): Promise<CleanupResult> {
    // waitUntil returns Promise<any>
    // eslint-disable-next-line @typescript-eslint/no-unsafe-return
    return waitUntil(event, async () => {
      const cache = await self.caches.open(this.strategy.cacheName);
      const currentlyCachedRequests = await cache.keys();
      const expectedCacheKeys = new Set(this._urlsToCacheKeys.values());

      const deletedURLs = [];
      for (const request of currentlyCachedRequests) {
        if (!expectedCacheKeys.has(request.url)) {
          await cache.delete(request);
          deletedURLs.push(request.url);
        }
      }

      if (process.env.NODE_ENV !== 'production') {
        printCleanupDetails(deletedURLs);
      }

      return {deletedURLs};
    });
  }

  /**
   * Returns a mapping of a precached URL to the corresponding cache key, taking
   * into account the revision information for the URL.
   *
   * @return {Map<string, string>} A URL to cache key mapping.
   */
  getURLsToCacheKeys(): Map<string, string> {
    return this._urlsToCacheKeys;
  }

  /**
   * Returns a list of all the URLs that have been precached by the current
   * service worker.
   *
   * @return {Array<string>} The precached URLs.
   */
  getCachedURLs(): Array<string> {
    return [...this._urlsToCacheKeys.keys()];
  }

  /**
   * Returns the cache key used for storing a given URL. If that URL is
   * unversioned, like `/index.html', then the cache key will be the original
   * URL with a search parameter appended to it.
   *
   * @param {string} url A URL whose cache key you want to look up.
   * @return {string} The versioned URL that corresponds to a cache key
   * for the original URL, or undefined if that URL isn't precached.
   */
  getCacheKeyForURL(url: string): string | undefined {
    const urlObject = new URL(url, location.href);
    return this._urlsToCacheKeys.get(urlObject.href);
  }

  /**
   * @param {string} url A cache key whose SRI you want to look up.
   * @return {string} The subresource integrity associated with the cache key,
   * or undefined if it's not set.
   */
  getIntegrityForCacheKey(cacheKey: string): string | undefined {
    return this._cacheKeysToIntegrities.get(cacheKey);
  }

  /**
   * This acts as a drop-in replacement for
   * [`cache.match()`](https://developer.mozilla.org/en-US/docs/Web/API/Cache/match)
   * with the following differences:
   *
   * - It knows what the name of the precache is, and only checks in that cache.
   * - It allows you to pass in an "original" URL without versioning parameters,
   * and it will automatically look up the correct cache key for the currently
   * active revision of that URL.
   *
   * E.g., `matchPrecache('index.html')` will find the correct precached
   * response for the currently active service worker, even if the actual cache
   * key is `'/index.html?__WB_REVISION__=1234abcd'`.
   *
   * @param {string|Request} request The key (without revisioning parameters)
   * to look up in the precache.
   * @return {Promise<Response|undefined>}
   */
  async matchPrecache(
    request: string | Request,
  ): Promise<Response | undefined> {
    const url = request instanceof Request ? request.url : request;
    const cacheKey = this.getCacheKeyForURL(url);
    if (cacheKey) {
      const cache = await self.caches.open(this.strategy.cacheName);
      return cache.match(cacheKey);
    }
    return undefined;
  }

  /**
   * Returns a function that looks up `url` in the precache (taking into
   * account revision information), and returns the corresponding `Response`.
   *
   * @param {string} url The precached URL which will be used to lookup the
   * `Response`.
   * @return {workbox-routing~handlerCallback}
   */
  createHandlerBoundToURL(url: string): RouteHandlerCallback {
    const cacheKey = this.getCacheKeyForURL(url);
    if (!cacheKey) {
      throw new WorkboxError('non-precached-url', {url});
    }
    return (options) => {
      options.request = new Request(url);
      options.params = {cacheKey, ...options.params};

      return this.strategy.handle(options);
    };
  }
}

export {PrecacheController};