NetworkOnly.ts 3.87 KB
/*
  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 {timeout} from 'workbox-core/_private/timeout.js';
import {WorkboxError} from 'workbox-core/_private/WorkboxError.js';

import {Strategy, StrategyOptions} from './Strategy.js';
import {StrategyHandler} from './StrategyHandler.js';
import {messages} from './utils/messages.js';
import './_version.js';

interface NetworkOnlyOptions
  extends Omit<StrategyOptions, 'cacheName' | 'matchOptions'> {
  networkTimeoutSeconds?: number;
}

/**
 * An implementation of a
 * [network-only](https://developer.chrome.com/docs/workbox/caching-strategies-overview/#network-only)
 * request strategy.
 *
 * This class is useful if you want to take advantage of any
 * [Workbox plugins](https://developer.chrome.com/docs/workbox/using-plugins/).
 *
 * If the network request fails, this will throw a `WorkboxError` exception.
 *
 * @extends workbox-strategies.Strategy
 * @memberof workbox-strategies
 */
class NetworkOnly extends Strategy {
  private readonly _networkTimeoutSeconds: number;

  /**
   * @param {Object} [options]
   * @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 {number} [options.networkTimeoutSeconds] If set, any network requests
   * that fail to respond within the timeout will result in a network error.
   */
  constructor(options: NetworkOnlyOptions = {}) {
    super(options);

    this._networkTimeoutSeconds = options.networkTimeoutSeconds || 0;
  }

  /**
   * @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: Request, handler: StrategyHandler): Promise<Response> {
    if (process.env.NODE_ENV !== 'production') {
      assert!.isInstance(request, Request, {
        moduleName: 'workbox-strategies',
        className: this.constructor.name,
        funcName: '_handle',
        paramName: 'request',
      });
    }

    let error: Error | undefined = undefined;
    let response: Response | undefined;

    try {
      const promises: Promise<Response | undefined>[] = [
        handler.fetch(request),
      ];

      if (this._networkTimeoutSeconds) {
        const timeoutPromise = timeout(
          this._networkTimeoutSeconds * 1000,
        ) as Promise<undefined>;
        promises.push(timeoutPromise);
      }

      response = await Promise.race(promises);
      if (!response) {
        throw new Error(
          `Timed out the network response after ` +
            `${this._networkTimeoutSeconds} seconds.`,
        );
      }
    } catch (err) {
      if (err instanceof Error) {
        error = err;
      }
    }

    if (process.env.NODE_ENV !== 'production') {
      logger.groupCollapsed(
        messages.strategyStart(this.constructor.name, request),
      );
      if (response) {
        logger.log(`Got response from network.`);
      } else {
        logger.log(`Unable to get a response from the network.`);
      }
      messages.printFinalResponse(response);
      logger.groupEnd();
    }

    if (!response) {
      throw new WorkboxError('no-response', {url: request.url, error});
    }
    return response;
  }
}

export {NetworkOnly, NetworkOnlyOptions};