Add a serviceworker (#234)

* Add a serviceworker

* rename + fix random extra character

* Fixing worker typings

* Fixing types properly this time.

* Once of those rare cases where this matters.

* Naming the things.

* Move registration to the app (so we can use snackbar later)

* Moving SW plugin later so it picks up things like HTML

* MVP service worker

* Two stage-service worker

* Fix prerendering by conditionally awaiting Custom Elements polyfill.

* Fix icon 404's

* add doc comment to autoswplugin

* Fix type

config/auto-sw-plugin.js

@@ -0,0 +1,156 @@
+const util = require('util');
+const minimatch = require('minimatch');
+const SingleEntryPlugin = require('webpack/lib/SingleEntryPlugin');
+const WebWorkerTemplatePlugin = require('webpack/lib/webworker/WebWorkerTemplatePlugin');
+const ParserHelpers = require('webpack/lib/ParserHelpers');
+
+const NAME = 'auto-sw-plugin';
+const JS_TYPES = ['auto', 'esm', 'dynamic'];
+
+/**
+ * Automatically finds and bundles Service Workers by looking for navigator.serviceWorker.register(..).
+ * An Array of webpack assets is injected into the Service Worker bundle as a `BUILD_ASSETS` global.
+ * Hidden and `.map` files are excluded by default, and this can be customized using the include & exclude options.
+ * @example
+ *  // webpack config
+ *  plugins: [
+ *    new AutoSWPlugin({
+ *      exclude: [
+ *        '**\/.*',     // don't expose hidden files (default)
+ *        '**\/*.map',  // don't precache sourcemaps (default)
+ *        'index.html'  // don't cache the page itself
+ *      ]
+ *    })
+ *  ]
+ * @param {Object} [options={}]
+ * @param {string[]} [options.exclude]  Minimatch pattern(s) of which assets to omit from BUILD_ASSETS.
+ * @param {string[]} [options.include]  Minimatch pattern(s) of assets to allow in BUILD_ASSETS.
+ */
+module.exports = class AutoSWPlugin {
+  constructor(options) {
+    this.options = Object.assign({
+      exclude: [
+        '**/*.map',
+        '**/.*'
+      ]
+    }, options || {});
+  }
+
+  apply(compiler) {
+    const serviceWorkers = [];
+
+    compiler.hooks.emit.tapPromise(NAME, compilation => this.emit(compiler, compilation, serviceWorkers));
+
+    compiler.hooks.normalModuleFactory.tap(NAME, (factory) => {
+      for (const type of JS_TYPES) {
+        factory.hooks.parser.for(`javascript/${type}`).tap(NAME, parser => {
+          let counter = 0;
+
+          const processRegisterCall = expr => {
+            const dep = parser.evaluateExpression(expr.arguments[0]);
+
+            if (!dep.isString()) {
+              parser.state.module.warnings.push({
+                message: 'navigator.serviceWorker.register() will only be bundled if passed a String literal.'
+              });
+              return false;
+            }
+
+            const filename = dep.string;
+            const outputFilename = this.options.filename || 'serviceworker.js'
+            const context = parser.state.current.context;
+            serviceWorkers.push({
+              outputFilename,
+              filename,
+              context
+            });
+
+            const id = `__webpack__serviceworker__${++counter}`;
+            ParserHelpers.toConstantDependency(parser, id)(expr.arguments[0]);
+            return ParserHelpers.addParsedVariableToModule(parser, id, '__webpack_public_path__ + ' + JSON.stringify(outputFilename));
+          };
+
+          parser.hooks.call.for('navigator.serviceWorker.register').tap(NAME, processRegisterCall);
+          parser.hooks.call.for('self.navigator.serviceWorker.register').tap(NAME, processRegisterCall);
+          parser.hooks.call.for('window.navigator.serviceWorker.register').tap(NAME, processRegisterCall);
+        });
+      }
+    });
+  }
+
+  createFilter(list) {
+    const filters = [].concat(list);
+    for (let i=0; i<filters.length; i++) {
+      if (typeof filters[i] === 'string') {
+        filters[i] = minimatch.filter(filters[i]);
+      }
+    }
+    return filters;
+  }
+
+  async emit(compiler, compilation, serviceWorkers) {
+    let assetMapping = Object.keys(compilation.assets);
+    if (this.options.include) {
+      const filters = this.createFilter(this.options.include);
+      assetMapping = assetMapping.filter(filename => {
+        for (const filter of filters) {
+          if (filter(filename)) return true;
+        }
+        return false;
+      });
+    }
+    if (this.options.exclude) {
+      const filters = this.createFilter(this.options.exclude);
+      assetMapping = assetMapping.filter(filename => {
+        for (const filter of filters) {
+          if (filter(filename)) return false;
+        }
+        return true;
+      });
+    }
+    await Promise.all(serviceWorkers.map(
+      (serviceWorker, index) => this.compileServiceWorker(compiler, compilation, serviceWorker, index, assetMapping)
+    ));
+  }
+
+  async compileServiceWorker(compiler, compilation, options, index, assetMapping) {
+    const entryFilename = options.filename;
+
+    const chunkFilename = compiler.options.output.chunkFilename.replace(/\.([a-z]+)$/i, '.serviceworker.$1');
+    const workerOptions = {
+      filename: options.outputFilename, // chunkFilename.replace(/\.?\[(?:chunkhash|contenthash|hash)(:\d+(?::\d+)?)?\]/g, ''),
+      chunkFilename: this.options.chunkFilename || chunkFilename,
+      globalObject: 'self'
+    };
+
+    const childCompiler = compilation.createChildCompiler(NAME, { filename: workerOptions.filename });
+    (new WebWorkerTemplatePlugin(workerOptions)).apply(childCompiler);
+
+    /* The duplication DefinePlugin ends up causing is problematic (it doesn't hoist injections), so we'll do it manually. */
+    // (new DefinePlugin({
+    //   BUILD_ASSETS: JSON.stringify(assetMapping)
+    // })).apply(childCompiler);
+    (new SingleEntryPlugin(options.context, entryFilename, workerOptions.filename)).apply(childCompiler);
+
+    const subCache = `subcache ${__dirname} ${entryFilename} ${index}`;
+    let childCompilation;
+    childCompiler.hooks.compilation.tap(NAME, c => {
+      childCompilation = c;
+      if (childCompilation.cache) {
+        if (!childCompilation.cache[subCache]) childCompilation.cache[subCache] = {};
+        childCompilation.cache = childCompilation.cache[subCache];
+      }
+    });
+
+    await (util.promisify(childCompiler.runAsChild.bind(childCompiler)))();
+
+    const original = childCompilation.assets[workerOptions.filename].source();
+    const source = `var BUILD_ASSETS=${JSON.stringify(assetMapping)};\n${original}`;
+    childCompilation.assets[workerOptions.filename] = {
+      source: () => source,
+      size: () => Buffer.byteLength(source, 'utf8')
+    };
+
+    Object.assign(compilation.assets, childCompilation.assets);
+  }
+};

package-lock.json

@@ -5553,6 +5553,12 @@
         }
       }
     },
+    "idb-keyval": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/idb-keyval/-/idb-keyval-3.1.0.tgz",
+      "integrity": "sha512-iFwFN5n00KNNnVxlOOK280SJJfXWY7pbMUOQXdIXehvvc/mGCV/6T2Ae+Pk2KwAkkATDTwfMavOiDH5lrJKWXQ==",
+      "dev": true
+    },
     "ieee754": {
       "version": "1.1.12",
       "resolved": "https://registry.npmjs.org/ieee754/-/ieee754-1.1.12.tgz",

package.json

@@ -40,6 +40,7 @@
     "file-loader": "^1.1.11",
     "html-webpack-plugin": "^3.2.0",
     "husky": "^1.1.2",
+    "idb-keyval": "^3.1.0",
     "if-env": "^1.0.4",
     "linkstate": "^1.1.1",
     "loader-utils": "^1.1.0",
@@ -47,6 +48,7 @@
     "node-sass": "^4.9.4",
     "optimize-css-assets-webpack-plugin": "^4.0.3",
     "pointer-tracker": "^2.0.3",
+    "minimatch": "^3.0.4",
     "preact": "^8.3.1",
     "pretty-bytes": "^5.1.0",
     "progress-bar-webpack-plugin": "^1.11.0",
@@ -62,7 +64,8 @@
     "tslint-react": "^3.6.0",
     "typescript": "^2.9.2",
     "typings-for-css-modules-loader": "^1.7.0",
-    "webpack": "=4.19.1",
+    "url-loader": "^1.1.2",
+    "webpack": "^4.19.1",
     "webpack-bundle-analyzer": "^2.13.1",
     "webpack-cli": "^2.1.5",
     "webpack-dev-server": "^3.1.5",

src/codecs/decoders.ts

@@ -1,9 +1,8 @@
 import { nativeDecode, sniffMimeType, canDecodeImage } from '../lib/util';
 import Processor from './processor';
+import webpDataUrl from 'url-loader!./tiny.webp';
 
-// tslint:disable-next-line:max-line-length It’s a data URL. Whatcha gonna do?
+const nativeWebPSupported = canDecodeImage(webpDataUrl);
-const webpFile = 'data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAAAAAAfQ//73v/+BiOh/AAA=';
-const nativeWebPSupported = canDecodeImage(webpFile);
 
 export async function decodeImage(blob: Blob, processor: Processor): Promise<ImageData> {
   const mimeType = await sniffMimeType(blob);

src/codecs/processor-worker.ts

@@ -7,31 +7,46 @@ import { EncodeOptions as WebPEncoderOptions } from './webp/encoder-meta';
 async function mozjpegEncode(
   data: ImageData, options: MozJPEGEncoderOptions,
 ): Promise<ArrayBuffer> {
-  const { encode } = await import('./mozjpeg/encoder');
+  const { encode } = await import(
+    /* webpackChunkName: "process-mozjpeg-enc" */
+    './mozjpeg/encoder',
+  );
   return encode(data, options);
 }
 
 async function quantize(data: ImageData, opts: QuantizeOptions): Promise<ImageData> {
-  const { process } = await import('./imagequant/processor');
+  const { process } = await import(
+    /* webpackChunkName: "process-imagequant" */
+    './imagequant/processor',
+  );
   return process(data, opts);
 }
 
 async function optiPngEncode(
   data: BufferSource, options: OptiPNGEncoderOptions,
 ): Promise<ArrayBuffer> {
-  const { compress } = await import('./optipng/encoder');
+  const { compress } = await import(
+    /* webpackChunkName: "process-optipng" */
+    './optipng/encoder',
+  );
   return compress(data, options);
 }
 
 async function webpEncode(
   data: ImageData, options: WebPEncoderOptions,
 ): Promise<ArrayBuffer> {
-  const { encode } = await import('./webp/encoder');
+  const { encode } = await import(
+    /* webpackChunkName: "process-webp-enc" */
+    './webp/encoder',
+  );
   return encode(data, options);
 }
 
 async function webpDecode(data: ArrayBuffer): Promise<ImageData> {
-  const { decode } = await import('./webp/decoder');
+  const { decode } = await import(
+    /* webpackChunkName: "process-webp-dec" */
+    './webp/decoder',
+  );
   return decode(data);
 }
 

src/codecs/processor.ts

@@ -61,7 +61,10 @@ export default class Processor {
           // worker-loader does magic here.
           // @ts-ignore - Typescript doesn't know about the 2nd param to new Worker, and the
           // definition can't be overwritten.
-          this._worker = new Worker('./processor-worker.ts', { type: 'module' }) as Worker;
+          this._worker = new Worker(
+            './processor-worker.ts',
+            { name: 'processor-worker', type: 'module' },
+          ) as Worker;
           // Need to do some TypeScript trickery to make the type match.
           this._workerApi = proxy(this._worker) as any as ProcessorWorkerApi;
         }

src/components/App/index.tsx

@@ -36,12 +36,17 @@ export default class App extends Component<Props, State> {
   constructor() {
     super();
 
-    import('../compress').then((module) => {
+    import(
+      /* webpackChunkName: "main-app" */
+      '../compress',
+    ).then((module) => {
       this.setState({ Compress: module.default });
     }).catch(() => {
       this.showSnack('Failed to load app');
     });
 
+    navigator.serviceWorker.register('../../sw');
+
     // In development, persist application state across hot reloads:
     if (process.env.NODE_ENV === 'development') {
       this.setState(window.STATE);

src/components/compress/index.tsx

@@ -1,4 +1,5 @@
 import { h, Component } from 'preact';
+import { get, set } from 'idb-keyval';
 
 import { bind, Fileish } from '../../lib/initial-util';
 import { blobToImg, drawableToImageData, blobToText } from '../../lib/util';
@@ -155,6 +156,12 @@ async function processSvg(blob: Blob): Promise<HTMLImageElement> {
   return blobToImg(new Blob([newSource], { type: 'image/svg+xml' }));
 }
 
+async function getOldestServiceWorker() {
+  const reg = await navigator.serviceWorker.getRegistration();
+  if (!reg) return null;
+  return reg.active || reg.waiting || reg.installing;
+}
+
 // These are only used in the mobile view
 const resultTitles = ['Top', 'Bottom'];
 // These are only used in the desktop view
@@ -195,6 +202,17 @@ export default class Compress extends Component<Props, State> {
     super(props);
     this.widthQuery.addListener(this.onMobileWidthChange);
     this.updateFile(props.file);
+
+    // If this is the first time the user has interacted with the app, tell the service worker to
+    // cache all the codecs.
+    get<boolean | undefined>('user-interacted')
+      .then(async (userInteracted: boolean | undefined) => {
+        if (userInteracted) return;
+        set('user-interacted', true);
+        const serviceWorker = await getOldestServiceWorker();
+        if (!serviceWorker) return; // Service worker not installing yet.
+        serviceWorker.postMessage('cache-all');
+      });
   }
 
   @bind

src/components/intro/index.tsx

@@ -4,13 +4,13 @@ import { bind, linkRef, Fileish } from '../../lib/initial-util';
 import '../custom-els/LoadingSpinner';
 
 import logo from './imgs/logo.svg';
-import largePhoto from './imgs/demos/large-photo.jpg';
+import largePhoto from './imgs/demos/demo-large-photo.jpg';
-import artwork from './imgs/demos/artwork.jpg';
+import artwork from './imgs/demos/demo-artwork.jpg';
-import deviceScreen from './imgs/demos/device-screen.png';
+import deviceScreen from './imgs/demos/demo-device-screen.png';
-import largePhotoIcon from './imgs/demos/large-photo-icon.jpg';
+import largePhotoIcon from './imgs/demos/icon-demo-large-photo.jpg';
-import artworkIcon from './imgs/demos/artwork-icon.jpg';
+import artworkIcon from './imgs/demos/icon-demo-artwork.jpg';
-import deviceScreenIcon from './imgs/demos/device-screen-icon.jpg';
+import deviceScreenIcon from './imgs/demos/icon-demo-device-screen.jpg';
-import logoIcon from './imgs/demos/logo-icon.png';
+import logoIcon from './imgs/demos/icon-demo-logo.png';
 import * as style from './style.scss';
 import SnackBarElement from '../../lib/SnackBar';
 

src/index.html

@@ -8,6 +8,7 @@
     <meta name="mobile-web-app-capable" content="yes">
     <meta name="apple-mobile-web-app-capable" content="yes">
     <meta name="theme-color" content="#673ab8">
+    <link rel="shortcut icon" href="/assets/favicon.ico">
     <link rel="manifest" href="/manifest.json">
   </head>
   <body>

src/index.ts

@@ -1,9 +1,14 @@
 declare module '@webcomponents/custom-elements';
 
-(async function () {
+function init() {
-  if (!('customElements' in self)) {
-    await import('@webcomponents/custom-elements');
-  }
-
   require('./init-app.tsx');
-})();
+}
+
+if (!('customElements' in self)) {
+  import(
+    /* webpackChunkName: "wc-polyfill" */
+    '@webcomponents/custom-elements',
+  ).then(init);
+} else {
+  init();
+}

src/init-app.tsx

@@ -9,8 +9,7 @@ let root = document.querySelector('#app') || undefined;
 // "attach" the client-side rendering to it, updating the DOM in-place instead of replacing:
 root = render(<App />, document.body, root);
 
-// In production, this entire condition is removed.
+if (process.env.NODE_ENV !== 'production') {
-if (process.env.NODE_ENV === 'development') {
   // Enable support for React DevTools and some helpful console warnings:
   require('preact/debug');
 

src/manifest.json

@@ -8,9 +8,9 @@
   "theme_color": "#673ab8",
   "icons": [
     {
-      "src": "/assets/icon.png",
+      "src": "/assets/icon-large.png",
       "type": "image/png",
-      "sizes": "512x512"
+      "sizes": "1024x1024"
     }
   ]
 }

src/missing-types.d.ts

@@ -27,3 +27,8 @@ declare module '*.wasm' {
   const content: string;
   export default content;
 }
+
+declare module 'url-loader!*' {
+  const value: string;
+  export default value;
+}

src/sw/index.ts

@@ -0,0 +1,63 @@
+import {
+  cacheOrNetworkAndCache, cleanupCache, cacheOrNetwork, cacheBasics, cacheAdditionalProcessors,
+} from './util';
+import { get } from 'idb-keyval';
+
+// Give TypeScript the correct global.
+declare var self: ServiceWorkerGlobalScope;
+// This is populated by webpack.
+declare var BUILD_ASSETS: string[];
+
+const version = '1.0.0';
+const versionedCache = 'static-' + version;
+const dynamicCache = 'dynamic';
+const expectedCaches = [versionedCache, dynamicCache];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(async function () {
+    const promises = [];
+    promises.push(cacheBasics(versionedCache, BUILD_ASSETS));
+
+    // If the user has already interacted with the app, update the codecs too.
+    if (await get('user-interacted')) {
+      promises.push(cacheAdditionalProcessors(versionedCache, BUILD_ASSETS));
+    }
+
+    await Promise.all(promises);
+  }());
+});
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(async function () {
+    // Remove old caches.
+    const promises = (await caches.keys()).map((cacheName) => {
+      if (!expectedCaches.includes(cacheName)) return caches.delete(cacheName);
+    });
+
+    await Promise.all<any>(promises);
+  }());
+});
+
+self.addEventListener('fetch', (event) => {
+  // We only care about GET.
+  if (event.request.method !== 'GET') return;
+
+  const url = new URL(event.request.url);
+
+  // Don't care about other-origin URLs
+  if (url.origin !== location.origin) return;
+
+  if (url.pathname.startsWith('/demo-') || url.pathname.startsWith('/wc-polyfill')) {
+    cacheOrNetworkAndCache(event, dynamicCache);
+    cleanupCache(event, dynamicCache, BUILD_ASSETS);
+    return;
+  }
+
+  cacheOrNetwork(event);
+});
+
+self.addEventListener('message', (event) => {
+  if (event.data === 'cache-all') {
+    event.waitUntil(cacheAdditionalProcessors(versionedCache, BUILD_ASSETS));
+  }
+});

src/sw/missing-types.d.ts

@@ -0,0 +1 @@
+import '../missing-types';

src/sw/tsconfig.json

@@ -0,0 +1,18 @@
+{
+  "compileOnSave": false,
+  "compilerOptions": {
+    "strict": true,
+    "target": "esnext",
+    "module": "esnext",
+    "lib": [
+      "webworker",
+      "esnext"
+    ],
+    "moduleResolution": "node",
+    "experimentalDecorators": true,
+    "noUnusedLocals": true,
+    "sourceMap": true,
+    "allowJs": false,
+    "baseUrl": "."
+  }
+}

src/sw/util.ts

@@ -0,0 +1,105 @@
+import webpDataUrl from 'url-loader!../codecs/tiny.webp';
+
+export function cacheOrNetwork(event: FetchEvent): void {
+  event.respondWith(async function () {
+    const cachedResponse = await caches.match(event.request);
+    return cachedResponse || fetch(event.request);
+  }());
+}
+
+export function cacheOrNetworkAndCache(event: FetchEvent, cacheName: string): void {
+  event.respondWith(async function () {
+    const { request } = event;
+    // Return from cache if possible.
+    const cachedResponse = await caches.match(request);
+    if (cachedResponse) return cachedResponse;
+
+    // Else go to the network.
+    const response = await fetch(request);
+    const responseToCache = response.clone();
+
+    event.waitUntil(async function () {
+      // Cache what we fetched.
+      const cache = await caches.open(cacheName);
+      await cache.put(request, responseToCache);
+    }());
+
+    // Return the network response.
+    return response;
+  }());
+}
+
+export function cleanupCache(event: FetchEvent, cacheName: string, keepAssets: string[]) {
+  event.waitUntil(async function () {
+    const cache = await caches.open(cacheName);
+
+    // Clean old entries from the dynamic cache.
+    const requests = await cache.keys();
+    const promises = requests.map((cachedRequest) => {
+      // Get pathname without leading /
+      const assetPath = new URL(cachedRequest.url).pathname.slice(1);
+      // If it isn't one of our keepAssets, we don't need it anymore.
+      if (!keepAssets.includes(assetPath)) return cache.delete(cachedRequest);
+    });
+
+    await Promise.all<any>(promises);
+  }());
+}
+
+export async function cacheBasics(cacheName: string, buildAssets: string[]) {
+  const toCache = ['/', '/assets/favicon.ico'];
+
+  const prefixesToCache = [
+    // First interaction JS & CSS:
+    'first-interaction.',
+    // Main app JS & CSS:
+    'main-app.',
+    // Little icons for the demo images on the homescreen:
+    'icon-demo-',
+    // Site logo:
+    'logo.',
+  ];
+
+  const prefixMatches = buildAssets.filter(
+    asset => prefixesToCache.some(prefix => asset.startsWith(prefix)),
+  );
+
+  toCache.push(...prefixMatches);
+
+  const cache = await caches.open(cacheName);
+  await cache.addAll(toCache);
+}
+
+export async function cacheAdditionalProcessors(cacheName: string, buildAssets: string[]) {
+  let toCache = [];
+
+  const prefixesToCache = [
+    // Worker which handles image processing:
+    'processor-worker.',
+    // processor-worker imports:
+    'process-',
+  ];
+
+  const prefixMatches = buildAssets.filter(
+    asset => prefixesToCache.some(prefix => asset.startsWith(prefix)),
+  );
+
+  const wasm = buildAssets.filter(asset => asset.endsWith('.wasm'));
+
+  toCache.push(...prefixMatches, ...wasm);
+
+  const supportsWebP = await (async () => {
+    if (!self.createImageBitmap) return false;
+    const response = await fetch(webpDataUrl);
+    const blob = await response.blob();
+    return createImageBitmap(blob).then(() => true, () => false);
+  })();
+
+  // No point caching the WebP decoder if it's supported natively:
+  if (supportsWebP) {
+    toCache = toCache.filter(asset => !/webp[\-_]dec/.test(asset));
+  }
+
+  const cache = await caches.open(cacheName);
+  await cache.addAll(toCache);
+}

tsconfig.json

@@ -12,5 +12,6 @@
     "jsxFactory": "h",
     "allowJs": false,
     "baseUrl": "."
-  }
+  },
+  "exclude": ["src/sw/**/*"]
 }

webpack.config.js

@@ -13,6 +13,7 @@ const CopyPlugin = require('copy-webpack-plugin');
 const WatchTimestampsPlugin = require('./config/watch-timestamps-plugin');
 const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
 const WorkerPlugin = require('worker-plugin');
+const AutoSWPlugin = require('./config/auto-sw-plugin');
 
 function readJson (filename) {
   return JSON.parse(fs.readFileSync(filename));
@@ -30,12 +31,14 @@ module.exports = function (_, env) {
 
   return {
     mode: isProd ? 'production' : 'development',
-    entry: './src/index',
+    entry: {
+      'first-interaction': './src/index'
+    },
     devtool: isProd ? 'source-map' : 'inline-source-map',
     stats: 'minimal',
     output: {
       filename: isProd ? '[name].[chunkhash:5].js' : '[name].js',
-      chunkFilename: '[name].chunk.[chunkhash:5].js',
+      chunkFilename: '[name].[chunkhash:5].js',
       path: path.join(__dirname, 'build'),
       publicPath: '/',
       globalObject: 'self'
@@ -154,11 +157,17 @@ module.exports = function (_, env) {
           // This is needed to make webpack NOT process wasm files.
           // See https://github.com/webpack/webpack/issues/6725
           type: 'javascript/auto',
-          loader: 'file-loader'
+          loader: 'file-loader',
+          options: {
+            name: '[name].[hash:5].[ext]',
+          },
         },
         {
           test: /\.(png|svg|jpg|gif)$/,
-          loader: 'file-loader'
+          loader: 'file-loader',
+          options: {
+            name: '[name].[hash:5].[ext]',
+          },
         }
       ]
     },
@@ -195,7 +204,7 @@ module.exports = function (_, env) {
       // See also: https://twitter.com/wsokra/status/970253245733113856
       isProd && new MiniCssExtractPlugin({
         filename: '[name].[contenthash:5].css',
-        chunkFilename: '[name].chunk.[contenthash:5].css'
+        chunkFilename: '[name].[contenthash:5].css'
       }),
 
       new OptimizeCssAssetsPlugin({
@@ -233,6 +242,8 @@ module.exports = function (_, env) {
         compile: true
       }),
 
+      new AutoSWPlugin({}),
+
       new ScriptExtHtmlPlugin({
         defaultAttribute: 'async'
       }),