Added missing webpack config that generates service worker

config/paths.js

@@ -83,6 +83,7 @@ module.exports = {
   appNodeModules: resolveApp('node_modules'),
   publicUrl: getPublicUrl(resolveApp('package.json')),
   servedPath: getServedPath(resolveApp('package.json')),
+  swSrc: resolveModule(resolveApp, 'src/service-worker'),
 };
 
 module.exports.moduleFileExtensions = moduleFileExtensions;

config/webpack.config.js

@@ -13,6 +13,7 @@ const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
 const safePostCssParser = require('postcss-safe-parser');
 const ManifestPlugin = require('webpack-manifest-plugin');
 const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
+const WorkboxWebpackPlugin = require('workbox-webpack-plugin');
 const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
 const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
 const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
@@ -32,6 +33,9 @@ const shouldInlineRuntimeChunk = process.env.INLINE_RUNTIME_CHUNK !== 'false';
 // Check if TypeScript is setup
 const useTypeScript = fs.existsSync(paths.appTsConfig);
 
+// Get the path to the uncompiled service worker (if it exists).
+const swSrc = paths.swSrc;
+
 // style files regexes
 const cssRegex = /\.css$/;
 const cssModuleRegex = /\.module\.css$/;
@@ -610,6 +614,18 @@ module.exports = (webpackEnv) => {
       // You can remove this if you don't use Moment.js:
       new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
 
+      // Generate a service worker script that will precache, and keep up to date,
+      // the HTML & assets that are part of the webpack build.
+      isEnvProduction && fs.existsSync(swSrc) && new WorkboxWebpackPlugin.InjectManifest({
+        swSrc,
+        dontCacheBustURLsMatching: /\.[0-9a-f]{8}\./,
+        exclude: [ /\.map$/, /asset-manifest\.json$/, /LICENSE/ ],
+        // Bump up the default maximum size (2mb) that's precached,
+        // to make lazy-loading failure scenarios less likely.
+        // See https://github.com/cra-template/pwa/issues/13#issuecomment-722667270
+        maximumFileSizeToCacheInBytes: 5 * 1024 * 1024,
+      }),
+
       // TypeScript type checking
       useTypeScript &&
         new ForkTsCheckerWebpackPlugin({