- [x] Upgrade to webpack 4.8.X (facebook#4077)

- [x] Utilize webpack 4 development and production modes
- [x] Upgrade webpack dev server
- [x] Webpack 4 compatible release of thread-loader
- [x] Webpack 4 compatible release of HtmlWebpackPlugin
- [x] Webpack 4 compatible release of SwPrecacheWebpackPlugin
- [x] Webpack 4 compatible release of WebpackManifestPlugin
- [x] Update README
- [x] Update WebpackDevServerUtils
- [x] Update InterpolateHtmlPlugin
- [x] Update ModuleScopePlugin
- [x] Update WatchMissingNodeModulesPlugin
- [x] Move UglifyJS options to webpack 4 optimize
- [x] Move InterpolateHtmlPlugin to make it tapable on HtmlWebpackPlugin
- [x] vendor splitting via splitChunks.splitChunks (https://twitter.com/wSokra/status/969633336732905474)
- [x] long term caching via splitChunks.runtimeChunk (https://twitter.com/wSokra/status/969679223278505985)
- [x] Make sure process.env.NODE_ENV is proxied correctly to `react-error-overlay`
- [x] Implicit webpack.NamedModulesPlugin in dev config as its default in webpack 4
- [x] Disable webpack performance hints as we have our own filesize reporter
- [x] Replace ExtractTextPlugin with MiniCssExtractPlugin
- [x] Switch to css whole file minification via OptimizeCSSAssetsPlugin rather than per module css minification to gain performance

Author: andriijas

config/webpack.config.dev.js

@@ -31,21 +31,6 @@ const publicUrl = '';
 // Get environment variables to inject into our app.
 const env = getClientEnvironment(publicUrl);
 
-// Options for PostCSS as we reference these options twice
-// Adds vendor prefixing based on your specified browser support in
-// package.json
-const postCSSLoaderOptions = {
-  // Necessary for external CSS imports to work
-  // https://github.com/facebook/create-react-app/issues/2677
-  ident: 'postcss',
-  plugins: () => [
-    require('postcss-flexbugs-fixes'),
-    autoprefixer({
-      flexbox: 'no-2009',
-    }),
-  ],
-};
-
 // style files regexes
 const cssRegex = /\.css$/;
 const cssModuleRegex = /\.module\.css$/;
@@ -61,8 +46,21 @@ const getStyleLoaders = (cssOptions, preProcessor) => {
       options: cssOptions,
     },
     {
+      // Options for PostCSS as we reference these options twice
+      // Adds vendor prefixing based on your specified browser support in
+      // package.json
       loader: require.resolve('postcss-loader'),
-      options: postCSSLoaderOptions,
+      options: {
+        // Necessary for external CSS imports to work
+        // https://github.com/facebook/create-react-app/issues/2677
+        ident: 'postcss',
+        plugins: () => [
+          require('postcss-flexbugs-fixes'),
+          autoprefixer({
+            flexbox: 'no-2009',
+          }),
+        ],
+      },
     },
   ];
   if (preProcessor) {
@@ -75,6 +73,7 @@ const getStyleLoaders = (cssOptions, preProcessor) => {
 // It is focused on developer experience and fast rebuilds.
 // The production configuration is different and lives in a separate file.
 module.exports = {
+  mode: 'development',
   // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
   // See the discussion in https://github.com/facebook/create-react-app/issues/343.
   devtool: 'cheap-module-source-map',
@@ -116,6 +115,18 @@ module.exports = {
     devtoolModuleFilenameTemplate: info =>
       path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
   },
+  optimization: {
+    // Automatically split vendor and commons
+    // https://twitter.com/wSokra/status/969633336732905474
+    // https://medium.com/webpack/webpack-4-code-splitting-chunk-graph-and-the-splitchunks-optimization-be739a861366
+    splitChunks: {
+      chunks: 'all',
+      name: 'vendors',
+    },
+    // Keep the runtime chunk seperated to enable long term caching
+    // https://twitter.com/wSokra/status/969679223278505985
+    runtimeChunk: true,
+  },
   resolve: {
     // This allows you to set a fallback for where Webpack should look for modules.
     // We placed these paths second because we want `node_modules` to "win"
@@ -335,18 +346,16 @@ module.exports = {
     ],
   },
   plugins: [
-    // Makes some environment variables available in index.html.
-    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
-    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
-    // In development, this will be an empty string.
-    new InterpolateHtmlPlugin(env.raw),
     // Generates an `index.html` file with the <script> injected.
     new HtmlWebpackPlugin({
       inject: true,
       template: paths.appHtml,
     }),
-    // Add module names to factory functions so they appear in browser profiler.
-    new webpack.NamedModulesPlugin(),
+    // Makes some environment variables available in index.html.
+    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
+    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
+    // In development, this will be an empty string.
+    new InterpolateHtmlPlugin(env.raw),
     // Makes some environment variables available to the JS code, for example:
     // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
     new webpack.DefinePlugin(env.stringified),
@@ -368,6 +377,7 @@ module.exports = {
     // You can remove this if you don't use Moment.js:
     new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
   ],
+
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.
   node: {
@@ -377,10 +387,7 @@ module.exports = {
     tls: 'empty',
     child_process: 'empty',
   },
-  // Turn off performance hints during development because we don't do any
-  // splitting or minification in interest of speed. These warnings become
-  // cumbersome.
-  performance: {
-    hints: false,
-  },
+  // Turn off performance processing because we utilize
+  // our own hints via the FileSizeReporter
+  performance: false,
 };