如何在 cra-template-pwa 模板 create-react-app 应用程序中正确使用 Workbox 文件 service-worker.js？

Question

我尝试使用 create-react-app 同时使用 3.4.1 和 4.0.0-next.77（生成的两个应用程序没有区别）通过

创建一个新的 PWA 应用程序

create-react-app my-app --template cra-template-pwa

代码在https://github.com/Hongbo-Miao/react-4-js-wb-test

有两个与service worker/Workbox相关的文件。

• service-worker.js
• serviceWorkerRegistration.js

这里是原始service-worker.js：

/* eslint-disable no-restricted-globals */

// This service worker can be customized!
// See https://developers.google.com/web/tools/workbox/modules
// for the list of available Workbox modules, or add any other
// code you'd like.
// You can also remove this file if you'd prefer not to use a
// service worker, and the Workbox build step will be skipped.

import { clientsClaim } from 'workbox-core';
import { ExpirationPlugin } from 'workbox-expiration';
import { precacheAndRoute, createHandlerBoundToURL } from 'workbox-precaching';
import { registerRoute } from 'workbox-routing';
import { StaleWhileRevalidate } from 'workbox-strategies';

clientsClaim();

// Precache all of the assets generated by your build process.
// Their URLs are injected into the manifest variable below.
// This variable must be present somewhere in your service worker file,
// even if you decide not to use precaching. See https://cra.link/PWA
precacheAndRoute(self.__WB_MANIFEST);

// Set up App Shell-style routing, so that all navigation requests
// are fulfilled with your index.html shell. Learn more at
// https://developers.google.com/web/fundamentals/architecture/app-shell
const fileExtensionRegexp = new RegExp('/[^/?]+\\.[^/]+$');
registerRoute(
  // Return false to exempt requests from being fulfilled by index.html.
  ({ request, url }) => {
    // If this isn't a navigation, skip.
    if (request.mode !== 'navigate') {
      return false;
    } // If this is a URL that starts with /_, skip.

    if (url.pathname.startsWith('/_')) {
      return false;
    } // If this looks like a URL for a resource, because it contains // a file extension, skip.

    if (url.pathname.match(fileExtensionRegexp)) {
      return false;
    } // Return true to signal that we want to use the handler.

    return true;
  },
  createHandlerBoundToURL(process.env.PUBLIC_URL + '/index.html')
);

// An example runtime caching route for requests that aren't handled by the
// precache, in this case same-origin .png requests like those from in public/
registerRoute(
  // Add in any other file extensions or routing criteria as needed.
  ({ url }) => url.origin === self.location.origin && url.pathname.endsWith('.png'), // Customize this strategy as needed, e.g., by changing to CacheFirst.
  new StaleWhileRevalidate({
    cacheName: 'images',
    plugins: [
      // Ensure that once this runtime cache reaches a maximum size the
      // least-recently used images are removed.
      new ExpirationPlugin({ maxEntries: 50 }),
    ],
  })
);

// This allows the web app to trigger skipWaiting via
// registration.waiting.postMessage({type: 'SKIP_WAITING'})
self.addEventListener('message', (event) => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});

// Any other custom service worker logic can go here.

根据里面的评论和the official doc，我想我应该可以自定义Workbox了。

我在 index.js 中通过将 unregister() 更改为 register() 来打开 service worker：

import * as serviceWorkerRegistration from './serviceWorkerRegistration';
serviceWorkerRegistration.register();

但是，我找不到使用 service-worker.js 的代码的任何部分，所以即使我添加了

console.log('Workbox got called in service-worker.js');

在内部，console.log 在开发环境中从未被调用过

yarn start

在 prod 环境中也没有

yarn build
serve build --ssl-cert ./my.crt --ssl-key ./my.key

我尝试添加

import './service-worker';

在 index.js

之上

但是，它会给我错误

not-an-array：传入'workbox-precaching.PrecacheController.addToCacheList()'的参数'entries'必须是一个数组。

根据报错，如果我把precacheAndRoute(self.__WB_MANIFEST);改成precacheAndRoute([self.__WB_MANIFEST]);，报错就变成了

add-to-cache-list-unexpected-type：一个意外的条目被传递到'workbox-precaching.PrecacheController.addToCacheList()' 不支持条目'undefined'。您必须提供包含一个或多个字符的字符串数组、具有 url 属性的对象或 Request 对象。

如何正确使用 Workbox 文件 service-worker.js？谢谢

---

更新：

我发现即使我删除了src/service-worker.js，再次yarn build，它仍然会生成一个build/service-worker.js（内容复制下面）与原始 src/service-worker.js 完全无关。

/**
 * Welcome to your Workbox-powered service worker!
 *
 * You'll need to register this file in your web app and you should
 * disable HTTP caching for this file too.
 *
 * The rest of the code is auto-generated. Please don't update this file
 * directly; instead, make changes to your Workbox build configuration
 * and re-run your build process.
 */

importScripts("https://storage.googleapis.com/workbox-cdn/releases/4.3.1/workbox-sw.js");

importScripts(
  "/precache-manifest.e90b8a1c98bf449d45dd07f902f9c090.js"
);

self.addEventListener('message', (event) => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});

workbox.core.clientsClaim();

/**
 * The workboxSW.precacheAndRoute() method efficiently caches and responds to
 * requests for URLs in the manifest.
 */
self.__precacheManifest = [].concat(self.__precacheManifest || []);
workbox.precaching.precacheAndRoute(self.__precacheManifest, {});

workbox.routing.registerNavigationRoute(workbox.precaching.getCacheKeyForURL("/index.html"), {
  
  blacklist: [/^\/_/,/\/[^/?]+\.[^/]+$/],
});

Answer 1

看看 serviceWorkerRegistration.js 里面，它正在注册 service-worker：

window.addEventListener("load", () => {
            const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

AFAIK 您无法移动此文件（由于 Workbox InjectManifest 工具将 self.__WB_MANIFEST 替换为您的静态资产列表）。

在使用具有正确模板的 CRA 后，一切都可以开箱即用（当然，调用 .register() 方法除外）。

我个人选择不在src\service.worker.js 中添加太多自定义代码，而是将我自己的代码导入其中（因为它已被转译，您可以添加任何您想要的内容）。