网站PWA升级

self: 表示 Service Worker 作用域, 也是全局变量
caches: 表示缓存
skipWaiting: 表示强制当前处在 waiting 状态的脚本进入 activate 状态
clients: 表示 Service Worker 接管的页面

    <script>
      (function() {
        if('serviceWorker' in navigator) {
          navigator.serviceWorker.register('/service-worker.js');
        }
      })()
    </script>

    const SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin');
    new SWPrecacheWebpackPlugin({
      // By default, a cache-busting query parameter is appended to requests
      // used to populate the caches, to ensure the responses are fresh.
      // If a URL is already hashed by Webpack, then there is no concern
      // about it being stale, and the cache-busting can be skipped.
      dontCacheBustUrlsMatching: /\.\w{8}\./,
      filename: 'service-worker.js',
      logger(message) {
        if (message.indexOf('Total precache size is') === 0) {
          // This message occurs for every build and is a bit too noisy.
          return;
        }
        if (message.indexOf('Skipping static resource') === 0) {
          // This message obscures real errors so we ignore it.
          // https://github.com/facebookincubator/create-react-app/issues/2612
          return;
        }
        console.log(message);
      },
      minify: true,
      // For unknown URLs, fallback to the index page
      navigateFallback: publicUrl + '/index.html',
      // Ignores URLs starting from /__ (useful for Firebase):
      // https://github.com/facebookincubator/create-react-app/issues/2237#issuecomment-302693219
      navigateFallbackWhitelist: [/^(?!\/__).*/],
      // Don't precache sourcemaps (they're large) and build asset manifest:
      staticFileGlobsIgnorePatterns: [/\.map$/, /asset-manifest\.json$/],
      runtimeCaching: [{
          urlPattern: '/',
          handler: 'networkFirst'
        },
        {
          urlPattern: /\/api/,
          handler: 'networkFirst'
        }
      ]
    })

    new SWPrecacheWebpackPlugin({
      dontCacheBustUrlsMatching: /\.\w{8}\./,
      filename: 'service-worker.js',
      logger(message) {
        if (message.indexOf('Total precache size is') === 0) {
          return;
        }
        if (message.indexOf('Skipping static resource') === 0) {
          return;
        }
        console.log(message);
      },
      navigateFallback: 'https://www.xiaohuochai.cc',
      minify: true,
      navigateFallbackWhitelist: [/^(?!\/__).*/],
      dontCacheBustUrlsMatching: /./,
      staticFileGlobsIgnorePatterns: [/\.map$/, /\.json$/],
      runtimeCaching: [{
          urlPattern: '/',
          handler: 'networkFirst'
        },
        {
          urlPattern: /\/(posts|categories|users|likes|comments)/,
          handler: 'networkFirst'
        },
      ]
    })
  ]

short_name: 应用展示的名字
icons: 定义不同尺寸的应用图标
start_url: 定义桌面启动的 URL
description: 应用描述
display: 定义应用的显示方式，有 4 种显示方式，分别为：
　　fullscreen: 全屏
　　standalone: 应用
　　minimal-ui: 类似于应用模式，但比应用模式多一些系统导航控制元素，但又不同于浏览器模式
　　browser: 浏览器模式，默认值
name: 应用名称
orientation: 定义默认应用显示方向，竖屏、横屏
prefer_related_applications: 是否设置对应移动应用，默认为 false
related_applications: 获取移动应用的方式
background_color: 应用加载之前的背景色，用于应用启动时的过渡
theme_color: 定义应用默认的主题色
dir: 文字方向，3 个值可选 ltr(left-to-right), rtl(right-to-left) 和 auto(浏览器判断)，默认为 auto
lang: 语言
scope: 定义应用模式下的路径范围，超出范围会以浏览器方式显示

{
  "name": "小火柴的前端小站",
  "short_name": "前端小站",
  "start_url": "/",
  "display": "standalone",
  "description": "",
  "theme_color": "#fff",
  "background_color": "#d8d8d8",
  "icons": [{
      "src": "./logo_32.png",
      "sizes": "32x32",
      "type": "image/png"
    },
    {
      "src": "./logo_48.png",
      "sizes": "48x48",
      "type": "image/png"
    },
    {
      "src": "./logo_96.png",
      "sizes": "96x96",
      "type": "image/png"
    },
    {
      "src": "./logo_144.png",
      "sizes": "144x144",
      "type": "image/png"
    },
    {
      "src": "./logo_192.png",
      "sizes": "192x192",
      "type": "image/png"
    },
    {
      "src": "./logo_256.png",
      "sizes": "256x256",
      "type": "image/png"
    }
  ]
}

Site cannot be installed: a 144px square PNG icon is required, but no supplied icon meets this requirement

localhost:3000/

localhost:3000/index.html

<link rel="manifest" href="/manifest.json">

Manifest is not valid JSON. Line: 1, column: 1, Unexpected token

<link rel="manifest" href="/manifest.json">

<link rel="manifest" href="/static/manifest.json" />

<meta name="theme-color" content="#fff"/>

app.use(express.static(path.join(__dirname, 'dist')))
app.use('/manifest.json', express.static(path.join(__dirname, 'manifest.json')))
app.use('/logo', express.static(path.join(__dirname, 'logo')))
app.use('/service-worker.js', express.static(path.join(__dirname, 'dist/service-worker.js')))