2.8.0 - Webpack 4, Babel 7

config/env.js

@@ -27,24 +27,27 @@ var dotenvFiles = [
 
 // Load environment variables from .env* files. Suppress warnings using silent
 // if this file is missing. dotenv will never modify any environment variables
-// that have already been set.
+// that have already been set.  Variable expansion is supported in .env files.
 // https://github.com/motdotla/dotenv
+// https://github.com/motdotla/dotenv-expand
 dotenvFiles.forEach(dotenvFile => {
   if (fs.existsSync(dotenvFile)) {
-    require('dotenv').config({
-      path: dotenvFile,
-    });
+    require('dotenv-expand')(
+      require('dotenv').config({
+        path: dotenvFile,
+      })
+    );
   }
 });
 
 // We support resolving modules according to `NODE_PATH`.
 // This lets you use absolute paths in imports inside large monorepos:
-// https://github.com/facebookincubator/create-react-app/issues/253.
+// https://github.com/facebook/create-react-app/issues/253.
 // It works similar to `NODE_PATH` in Node itself:
 // https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders
 // Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored.
 // Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims.
-// https://github.com/facebookincubator/create-react-app/issues/1023#issuecomment-265344421
+// https://github.com/facebook/create-react-app/issues/1023#issuecomment-265344421
 // We also resolve them to make sure all tools using them work consistently.
 const appDirectory = fs.realpathSync(process.cwd());
 process.env.NODE_PATH = (process.env.NODE_PATH || '')

config/jest/cssTransform.js

@@ -1,7 +1,7 @@
 'use strict';
 
 // This is a custom Jest transformer turning style imports into empty objects.
-// http://facebook.github.io/jest/docs/tutorial-webpack.html
+// http://facebook.github.io/jest/docs/en/webpack.html
 
 module.exports = {
   process() {

config/jest/fileTransform.js

@@ -3,10 +3,28 @@
 const path = require('path');
 
 // This is a custom Jest transformer turning file imports into filenames.
-// http://facebook.github.io/jest/docs/tutorial-webpack.html
+// http://facebook.github.io/jest/docs/en/webpack.html
 
 module.exports = {
   process(src, filename) {
-    return `module.exports = ${JSON.stringify(path.basename(filename))};`;
+    const assetFilename = JSON.stringify(path.basename(filename));
+
+    if (filename.match(/\.svg$/)) {
+      return `module.exports = {
+        __esModule: true,
+        default: ${assetFilename},
+        ReactComponent: (props) => ({
+          $$typeof: Symbol.for('react.element'),
+          type: 'svg',
+          ref: null,
+          key: null,
+          props: Object.assign({}, props, {
+            children: ${assetFilename}
+          })
+        }),
+      };`;
+    }
+
+    return `module.exports = ${assetFilename};`;
   },
 };

config/paths.js

@@ -5,20 +5,20 @@ const fs = require('fs');
 const url = require('url');
 
 // Make sure any symlinks in the project folder are resolved:
-// https://github.com/facebookincubator/create-react-app/issues/637
+// https://github.com/facebook/create-react-app/issues/637
 const appDirectory = fs.realpathSync(process.cwd());
 const resolveApp = relativePath => path.resolve(appDirectory, relativePath);
 
 const envPublicUrl = process.env.PUBLIC_URL;
 
-function ensureSlash(path, needsSlash) {
-  const hasSlash = path.endsWith('/');
+function ensureSlash(inputPath, needsSlash) {
+  const hasSlash = inputPath.endsWith('/');
   if (hasSlash && !needsSlash) {
-    return path.substr(path, path.length - 1);
+    return inputPath.substr(0, inputPath.length - 1);
   } else if (!hasSlash && needsSlash) {
-    return `${path}/`;
+    return `${inputPath}/`;
   } else {
-    return path;
+    return inputPath;
   }
 }
 
@@ -38,27 +38,56 @@ function getServedPath(appPackageJson) {
   return ensureSlash(servedUrl, true);
 }
 
+const moduleFileExtensions = [
+  'web.mjs',
+  'mjs',
+  'web.js',
+  'js',
+  'web.ts',
+  'ts',
+  'web.tsx',
+  'tsx',
+  'json',
+  'web.jsx',
+  'jsx',
+];
+
+// Resolve file paths in the same order as webpack
+const resolveModule = (resolveFn, filePath) => {
+  const extension = moduleFileExtensions.find(extension =>
+    fs.existsSync(resolveFn(`${filePath}.${extension}`))
+  );
+
+  if (extension) {
+    return resolveFn(`${filePath}.${extension}`);
+  }
+
+  return resolveFn(`${filePath}.js`);
+};
+
 // config after eject: we're in ./config/
 module.exports = {
   dotenv: resolveApp('.env'),
+  appPath: resolveApp('.'),
   appBuild: resolveApp('build'),
-  appDemoBuild: resolveApp('demo'),
+  appDemo: resolveApp('demo'),
   appPublic: resolveApp('public'),
   appHtml: resolveApp('public/index.html'),
-  appIndexJs: resolveApp('src/demo/index.js'), // CRL: Updated for demo purposes
+  appIndexJs: resolveModule(resolveApp, 'src/demo/index'),
+  appLibIndexJs: resolveModule(resolveApp, 'src/lib/index'),
+  appDemoIndexJs: resolveModule(resolveApp, 'src/demo/index'),
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
+  appSrcLib: resolveApp('src/lib'),
+  appSrcDemo: resolveApp('src/demo'),
+  appTsConfig: resolveApp('tsconfig.json'),
   yarnLockFile: resolveApp('yarn.lock'),
-  testsSetup: resolveApp('src/setupTests.js'),
+  testsSetup: resolveModule(resolveApp, 'src/setupTests'),
+  proxySetup: resolveApp('src/setupProxy.js'),
   appNodeModules: resolveApp('node_modules'),
   publicUrl: getPublicUrl(resolveApp('package.json')),
-  servedPath: getServedPath(resolveApp('package.json')),
-
-  // CRL: New paths for demo build
-  appDemoIndexJs: resolveApp('src/demo/index.js'),
-  appDemoSrc: resolveApp('src/demo'),
-
-  // CRL: New paths for library
-  appLibIndexJs: resolveApp('src/lib/index.js'),
-  appLibSrc: resolveApp('src/lib'),
+  //servedPath: getServedPath(resolveApp('package.json')),
+  servedPath: ''
 };
+
+module.exports.moduleFileExtensions = moduleFileExtensions;

config/polyfills.js

@@ -1,22 +0,0 @@
-'use strict';
-
-if (typeof Promise === 'undefined') {
-  // Rejection tracking prevents a common issue where React gets into an
-  // inconsistent state due to an error, but it gets swallowed by a Promise,
-  // and the user has no idea what causes React's erratic future behavior.
-  require('promise/lib/rejection-tracking').enable();
-  window.Promise = require('promise/lib/es6-extensions.js');
-}
-
-// fetch() polyfill for making API calls.
-require('whatwg-fetch');
-
-// Object.assign() is commonly used with React.
-// It will use the native implementation if it's present and isn't buggy.
-Object.assign = require('object-assign');
-
-// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
-// We don't polyfill it in the browser--this is user's responsibility.
-if (process.env.NODE_ENV === 'test') {
-  require('raf').polyfill(global);
-}

config/webpack.config.demo.js

@@ -1,16 +1,27 @@
+'use strict';
 
-
-const autoprefixer = require('autoprefixer');
+const fs = require('fs');
 const path = require('path');
 const webpack = require('webpack');
+const resolve = require('resolve');
+const PnpWebpackPlugin = require('pnp-webpack-plugin');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
-const CopyWebpackPlugin = require('copy-webpack-plugin');
+const InlineChunkHtmlPlugin = require('react-dev-utils/InlineChunkHtmlPlugin');
+const TerserPlugin = require('terser-webpack-plugin');
+const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+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 ExtractTextPlugin = require('extract-text-webpack-plugin');
-const eslintFormatter = require('react-dev-utils/eslintFormatter');
+const WorkboxWebpackPlugin = require('workbox-webpack-plugin');
 const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
+const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
 const paths = require('./paths');
 const getClientEnvironment = require('./env');
+const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
+const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
+const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
+
 
 // Webpack uses `publicPath` to determine where the app is being served from.
 // It requires a trailing slash, or the file assets will get an incorrect path.
@@ -20,10 +31,13 @@ const publicPath = paths.servedPath;
 const shouldUseRelativeAssetPaths = publicPath === './';
 // Source maps are resource heavy and can cause out of memory issue for large source files.
 const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
+// Some apps do not need the benefits of saving a web request, so not inlining the chunk
+// makes for a smoother build process.
+const shouldInlineRuntimeChunk = process.env.INLINE_RUNTIME_CHUNK !== 'false';
 // `publicUrl` is just like `publicPath`, but we will provide it to our app
 // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
 // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
-const publicUrl = '.';
+const publicUrl = publicPath.slice(0, -1);
 // Get environment variables to inject into our app.
 const env = getClientEnvironment(publicUrl);
 
@@ -33,88 +47,228 @@ if (env.stringified['process.env'].NODE_ENV !== '"production"') {
   throw new Error('Production builds must have NODE_ENV=production.');
 }
 
-// Note: defined here because it will be used more than once.
-const cssFilename = 'css/index.css';
+// Check if TypeScript is setup
+const useTypeScript = fs.existsSync(paths.appTsConfig);
 
-// ExtractTextPlugin expects the build output to be flat.
-// (See https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/27)
-// However, our output is structured with css, js and media folders.
-// To have this structure working with relative paths, we have to use custom options.
-const extractTextPluginOptions = shouldUseRelativeAssetPaths
-  ? // Making sure that the publicPath goes back to to build folder.
-    { publicPath: Array(cssFilename.split('/').length).join('../') }
-  : {};
+// style files regexes
+const cssRegex = /\.css$/;
+const cssModuleRegex = /\.module\.css$/;
+const sassRegex = /\.(scss|sass)$/;
+const sassModuleRegex = /\.module\.(scss|sass)$/;
+
+// common function to get style loaders
+const getStyleLoaders = (cssOptions, preProcessor) => {
+  const loaders = [
+    {
+      loader: MiniCssExtractPlugin.loader,
+      options: Object.assign(
+        {},
+        shouldUseRelativeAssetPaths ? { publicPath: '../../' } : undefined
+      ),
+    },
+    {
+      loader: require.resolve('css-loader'),
+      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: {
+        // Necessary for external CSS imports to work
+        // https://github.com/facebook/create-react-app/issues/2677
+        ident: 'postcss',
+        plugins: () => [
+          require('postcss-flexbugs-fixes'),
+          require('postcss-preset-env')({
+            autoprefixer: {
+              flexbox: 'no-2009',
+            },
+            stage: 3,
+          }),
+        ],
+        sourceMap: shouldUseSourceMap,
+      },
+    },
+  ];
+  if (preProcessor) {
+    loaders.push({
+      loader: require.resolve(preProcessor),
+      options: {
+        sourceMap: shouldUseSourceMap,
+      },
+    });
+  }
+  return loaders;
+};
 
 // This is the production configuration.
 // It compiles slowly and is focused on producing a fast and minimal bundle.
 // The development configuration is different and lives in a separate file.
 module.exports = {
+  mode: 'production',
   // Don't attempt to continue if there are any errors.
   bail: true,
   // We generate sourcemaps in production. This is slow but gives good results.
   // You can exclude the *.map files from the build during deployment.
   devtool: shouldUseSourceMap ? 'source-map' : false,
   // In production, we only want to load the app code.
-  entry: [paths.appDemoIndexJs], // CRL: library index file instead of app index
+  entry: [paths.appDemoIndexJs],
   output: {
-    // CRL: Updated whole block with library specific info
-    path: paths.appDemoBuild,
+    // The build folder.
+    path: paths.appDemo,
+    // Generated JS file names (with nested folders).
+    // There will be one main bundle, and one file per asynchronous chunk.
+    // We don't currently advertise code splitting but Webpack supports it.
     filename: 'index.js',
-    libraryTarget: 'umd',
-    library: 'SimpleKeyboard'
+    chunkFilename: 'index.[chunkhash:8].chunk.js',
+    // We inferred the "public path" (such as / or /my-project) from homepage.
+    publicPath: publicPath,
+    // Point sourcemap entries to original disk location (format as URL on Windows)
+    devtoolModuleFilenameTemplate: info =>
+      path
+        .relative(paths.appSrcDemo, info.absoluteResourcePath)
+        .replace(/\\/g, '/'),
+  },
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        terserOptions: {
+          parse: {
+            // we want terser to parse ecma 8 code. However, we don't want it
+            // to apply any minfication steps that turns valid ecma 5 code
+            // into invalid ecma 5 code. This is why the 'compress' and 'output'
+            // sections only apply transformations that are ecma 5 safe
+            // https://github.com/facebook/create-react-app/pull/4234
+            ecma: 8,
+          },
+          compress: {
+            ecma: 5,
+            warnings: false,
+            // Disabled because of an issue with Uglify breaking seemingly valid code:
+            // https://github.com/facebook/create-react-app/issues/2376
+            // Pending further investigation:
+            // https://github.com/mishoo/UglifyJS2/issues/2011
+            comparisons: false,
+            // Disabled because of an issue with Terser breaking valid code:
+            // https://github.com/facebook/create-react-app/issues/5250
+            // Pending futher investigation:
+            // https://github.com/terser-js/terser/issues/120
+            inline: 2,
+          },
+          mangle: {
+            safari10: true,
+          },
+          output: {
+            ecma: 5,
+            comments: false,
+            // Turned on because emoji and regex is not minified properly using default
+            // https://github.com/facebook/create-react-app/issues/2488
+            ascii_only: true,
+          },
+        },
+        // Use multi-process parallel running to improve the build speed
+        // Default number of concurrent runs: os.cpus().length - 1
+        parallel: true,
+        // Enable file caching
+        cache: true,
+        sourceMap: shouldUseSourceMap,
+      }),
+      new OptimizeCSSAssetsPlugin({
+        cssProcessorOptions: {
+          parser: safePostCssParser,
+          map: shouldUseSourceMap
+            ? {
+                // `inline: false` forces the sourcemap to be output into a
+                // separate file
+                inline: false,
+                // `annotation: true` appends the sourceMappingURL to the end of
+                // the css file, helping the browser find the sourcemap
+                annotation: true,
+              }
+            : false,
+        },
+      }),
+    ],
+    // 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: false,*/
+      cacheGroups: {
+        default: false,
+      }
+    },
+    // Keep the runtime chunk seperated to enable long term caching
+    // https://twitter.com/wSokra/status/969679223278505985
+    runtimeChunk: false,
   },
   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"
     // if there are any conflicts. This matches Node resolution mechanism.
-    // https://github.com/facebookincubator/create-react-app/issues/253
-    modules: ['node_modules', paths.appNodeModules].concat(
+    // https://github.com/facebook/create-react-app/issues/253
+    modules: ['node_modules'].concat(
       // It is guaranteed to exist because we tweak it in `env.js`
       process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
     ),
     // These are the reasonable defaults supported by the Node ecosystem.
     // We also include JSX as a common component filename extension to support
     // some tools, although we do not recommend using it, see:
-    // https://github.com/facebookincubator/create-react-app/issues/290
+    // https://github.com/facebook/create-react-app/issues/290
     // `web` extension prefixes have been added for better support
     // for React Native Web.
-    extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
+    extensions: paths.moduleFileExtensions
+      .map(ext => `.${ext}`)
+      .filter(ext => useTypeScript || !ext.includes('ts')),
     alias: {
       // Support React Native Web
       // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
-      'react-native': 'react-native-web'
+      'react-native': 'react-native-web',
     },
     plugins: [
+      // Adds support for installing with Plug'n'Play, leading to faster installs and adding
+      // guards against forgotten dependencies and such.
+      PnpWebpackPlugin,
       // Prevents users from importing files from outside of src/ (or node_modules/).
       // This often causes confusion because we only process files within src/ with babel.
       // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
       // please link the files into your node_modules/ and let module-resolution kick in.
       // Make sure your source files are compiled, as they will not be processed in any way.
-      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson])
-    ]
+      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
+    ],
+  },
+  resolveLoader: {
+    plugins: [
+      // Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
+      // from the current package.
+      PnpWebpackPlugin.moduleLoader(module),
+    ],
   },
   module: {
     strictExportPresence: true,
     rules: [
-      // TODO: Disable require.ensure as it's not a standard language feature.
-      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
-      // { parser: { requireEnsure: false } },
+      // Disable require.ensure as it's not a standard language feature.
+      { parser: { requireEnsure: false } },
 
       // First, run the linter.
       // It's important to do this before Babel processes the JS.
       {
-        test: /\.(js|jsx|mjs)$/,
+        test: /\.(js|mjs|jsx)$/,
         enforce: 'pre',
         use: [
           {
             options: {
-              formatter: eslintFormatter,
-              eslintPath: require.resolve('eslint')
+              formatter: require.resolve('react-dev-utils/eslintFormatter'),
+              eslintPath: require.resolve('eslint'),
+              
             },
-            loader: require.resolve('eslint-loader')
-          }
+            loader: require.resolve('eslint-loader'),
+          },
         ],
-        include: paths.appDemoSrc // CRL: updated with library src folder
+        include: paths.appSrcDemo,
       },
       {
         // "oneOf" will traverse all following loaders until one will
@@ -128,76 +282,129 @@ module.exports = {
             loader: require.resolve('url-loader'),
             options: {
               limit: 10000,
-              name: 'media/[name].[ext]'
-            }
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
           },
-          // Process JS with Babel.
+          // Process application JS with Babel.
+          // The preset includes JSX, Flow, TypeScript and some ESnext features.
           {
-            test: /\.(js|jsx|mjs)$/,
-            include: [paths.appLibSrc, paths.appDemoSrc], // CRL: updated with library src folder
+            test: /\.(js|mjs|jsx|ts|tsx)$/,
+            include: paths.appSrcDemo,
+
             loader: require.resolve('babel-loader'),
             options: {
-              compact: true
-            }
+              customize: require.resolve(
+                'babel-preset-react-app/webpack-overrides'
+              ),
+              
+              plugins: [
+                [
+                  require.resolve('babel-plugin-named-asset-import'),
+                  {
+                    loaderMap: {
+                      svg: {
+                        ReactComponent: '@svgr/webpack?-prettier,-svgo![path]',
+                      },
+                    },
+                  },
+                ],
+              ],
+              cacheDirectory: true,
+              // Save disk space when time isn't as important
+              cacheCompression: true,
+              compact: true,
+            },
+          },
+          // Process any JS outside of the app with Babel.
+          // Unlike the application JS, we only compile the standard ES features.
+          {
+            test: /\.(js|mjs)$/,
+            exclude: /@babel(?:\/|\\{1,2})runtime/,
+            loader: require.resolve('babel-loader'),
+            options: {
+              babelrc: false,
+              configFile: false,
+              compact: false,
+              presets: [
+                [
+                  require.resolve('babel-preset-react-app/dependencies'),
+                  { helpers: true },
+                ],
+              ],
+              cacheDirectory: true,
+              // Save disk space when time isn't as important
+              cacheCompression: true,
+              
+              // If an error happens in a package, it's possible to be
+              // because it was compiled. Thus, we don't want the browser
+              // debugger to show the original code. Instead, the code
+              // being evaluated would be much more helpful.
+              sourceMaps: false,
+            },
           },
-          // The notation here is somewhat confusing.
           // "postcss" loader applies autoprefixer to our CSS.
           // "css" loader resolves paths in CSS and adds assets as dependencies.
-          // "style" loader normally turns CSS into JS modules injecting <style>,
-          // but unlike in development configuration, we do something different.
-          // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
-          // (second argument), then grabs the result CSS and puts it into a
-          // separate file in our build process. This way we actually ship
-          // a single CSS file in production instead of JS code injecting <style>
-          // tags. If you use code splitting, however, any async bundles will still
-          // use the "style" loader inside the async code so CSS from them won't be
-          // in the main CSS file.
+          // `MiniCSSExtractPlugin` extracts styles into CSS
+          // files. If you use code splitting, async bundles will have their own separate CSS chunk file.
+          // By default we support CSS Modules with the extension .module.css
           {
-            test: /\.css$/,
-            loader: ExtractTextPlugin.extract(
-              Object.assign(
-                {
-                  fallback: {
-                    loader: require.resolve('style-loader'),
-                    options: {
-                      hmr: false
-                    }
-                  },
-                  use: [
-                    {
-                      loader: require.resolve('css-loader'),
-                      options: {
-                        importLoaders: 1,
-                        minimize: true,
-                        sourceMap: shouldUseSourceMap
-                      }
-                    },
-                    {
-                      loader: require.resolve('postcss-loader'),
-                      options: {
-                        // Necessary for external CSS imports to work
-                        // https://github.com/facebookincubator/create-react-app/issues/2677
-                        ident: 'postcss',
-                        plugins: () => [
-                          require('postcss-flexbugs-fixes'),
-                          autoprefixer({
-                            browsers: [
-                              '>1%',
-                              'last 4 versions',
-                              'Firefox ESR',
-                              'not ie < 9' // React doesn't support IE8 anyway
-                            ],
-                            flexbox: 'no-2009'
-                          })
-                        ]
-                      }
-                    }
-                  ]
-                },
-                extractTextPluginOptions
-              )
-            )
-            // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
+            test: cssRegex,
+            exclude: cssModuleRegex,
+            loader: getStyleLoaders({
+              importLoaders: 1,
+              sourceMap: shouldUseSourceMap,
+            }),
+            // Don't consider CSS imports dead code even if the
+            // containing package claims to have no side effects.
+            // Remove this when webpack adds a warning or an error for this.
+            // See https://github.com/webpack/webpack/issues/6571
+            sideEffects: true,
+          },
+          // Adds support for CSS Modules (https://github.com/css-modules/css-modules)
+          // using the extension .module.css
+          {
+            test: cssModuleRegex,
+            loader: getStyleLoaders({
+              importLoaders: 1,
+              sourceMap: shouldUseSourceMap,
+              modules: true,
+              getLocalIdent: getCSSModuleLocalIdent,
+            }),
+          },
+          // Opt-in support for SASS. The logic here is somewhat similar
+          // as in the CSS routine, except that "sass-loader" runs first
+          // to compile SASS files into CSS.
+          // By default we support SASS Modules with the
+          // extensions .module.scss or .module.sass
+          {
+            test: sassRegex,
+            exclude: sassModuleRegex,
+            loader: getStyleLoaders(
+              {
+                importLoaders: 2,
+                sourceMap: shouldUseSourceMap,
+              },
+              'sass-loader'
+            ),
+            // Don't consider CSS imports dead code even if the
+            // containing package claims to have no side effects.
+            // Remove this when webpack adds a warning or an error for this.
+            // See https://github.com/webpack/webpack/issues/6571
+            sideEffects: true,
+          },
+          // Adds support for CSS Modules, but using SASS
+          // using the extension .module.scss or .module.sass
+          {
+            test: sassModuleRegex,
+            loader: getStyleLoaders(
+              {
+                importLoaders: 2,
+                sourceMap: shouldUseSourceMap,
+                modules: true,
+                getLocalIdent: getCSSModuleLocalIdent,
+              },
+              'sass-loader'
+            ),
           },
           // "file" loader makes sure assets end up in the `build` folder.
           // When you `import` an asset, you get its filename.
@@ -206,68 +413,120 @@ module.exports = {
           {
             loader: require.resolve('file-loader'),
             // Exclude `js` files to keep "css" loader working as it injects
-            // it's runtime that would otherwise processed through "file" loader.
+            // it's runtime that would otherwise be processed through "file" loader.
             // Also exclude `html` and `json` extensions so they get processed
             // by webpacks internal loaders.
-            exclude: [/\.js$/, /\.html$/, /\.json$/],
+            exclude: [/\.(js|mjs|jsx|ts|tsx)$/, /\.html$/, /\.json$/],
             options: {
-              name: 'media/[name].[ext]'
-            }
-          }
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
+          },
           // ** STOP ** Are you adding a new loader?
           // Make sure to add the new loader(s) before the "file" loader.
-        ]
-      }
-    ]
+        ],
+      },
+    ],
   },
   plugins: [
+    // Generates an `index.html` file with the <script> injected.
+    new HtmlWebpackPlugin({
+      inject: true,
+      template: paths.appHtml,
+      minify: {
+        removeComments: true,
+        collapseWhitespace: true,
+        removeRedundantAttributes: true,
+        useShortDoctype: true,
+        removeEmptyAttributes: true,
+        removeStyleLinkTypeAttributes: true,
+        keepClosingSlash: true,
+        minifyJS: true,
+        minifyCSS: true,
+        minifyURLs: true,
+      },
+    }),
+    // Inlines the webpack runtime script. This script is too small to warrant
+    // a network request.
+    shouldInlineRuntimeChunk &&
+      new InlineChunkHtmlPlugin(HtmlWebpackPlugin, [/runtime~.+[.]js/]),
+    // 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 production, it will be an empty string unless you specify "homepage"
+    // in `package.json`, in which case it will be the pathname of that URL.
+    new InterpolateHtmlPlugin(HtmlWebpackPlugin, env.raw),
+    // This gives some necessary context to module not found errors, such as
+    // the requesting resource.
+    new ModuleNotFoundPlugin(paths.appPath),
     // Makes some environment variables available to the JS code, for example:
     // if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
     // It is absolutely essential that NODE_ENV was set to production here.
     // Otherwise React will be compiled in the very slow development mode.
-    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(),
     new webpack.DefinePlugin(env.stringified),
-    // Minify the code.
-    new webpack.optimize.UglifyJsPlugin({
-      compress: false,
-      mangle: {
-        safari10: true
-      },
-      output: {
-        comments: false,
-        // Turned on because emoji and regex is not minified properly using default
-        // https://github.com/facebookincubator/create-react-app/issues/2488
-        ascii_only: true
-      },
-      sourceMap: shouldUseSourceMap
-    }),
-    // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
-    new ExtractTextPlugin({
-      filename: cssFilename
+    new MiniCssExtractPlugin({
+      // Options similar to the same options in webpackOptions.output
+      // both options are optional
+      filename: 'index.css',
+      chunkFilename: 'index.[contenthash:8].chunk.css',
     }),
+    // Generate a manifest file which contains a mapping of all asset filenames
+    // to their corresponding output file so that tools can pick it up without
+    // having to parse `index.html`.
+    /*new ManifestPlugin({
+      fileName: 'asset-manifest.json',
+      publicPath: publicPath,
+    }),*/
     // Moment.js is an extremely popular library that bundles large locale files
     // by default due to how Webpack interprets its code. This is a practical
     // solution that requires the user to opt into importing specific locales.
     // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
     // You can remove this if you don't use Moment.js:
     new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
-    new CopyWebpackPlugin([
-      { from: `${paths.appPublic}/favicon.ico`, to: paths.appDemoBuild },
-      { from: `${paths.appPublic}/manifest.json`, to: paths.appDemoBuild }
-    ])
-  ],
-  // CRL: added externals block for library
-  // externals: {
-  //  'react': 'react',
-  //  'react-dom': 'react-dom'
-  // },
+    // Generate a service worker script that will precache, and keep up to date,
+    // the HTML & assets that are part of the Webpack build.
+    /*new WorkboxWebpackPlugin.GenerateSW({
+      clientsClaim: true,
+      exclude: [/\.map$/, /asset-manifest\.json$/],
+      importWorkboxFrom: 'cdn',
+      navigateFallback: publicUrl + '/index.html',
+      navigateFallbackBlacklist: [
+        // Exclude URLs starting with /_, as they're likely an API call
+        new RegExp('^/_'),
+        // Exclude URLs containing a dot, as they're likely a resource in
+        // public/ and not a SPA route
+        new RegExp('/[^/]+\\.[^/]+$'),
+      ],
+    }),*/
+    // TypeScript type checking
+    fs.existsSync(paths.appTsConfig) &&
+      new ForkTsCheckerWebpackPlugin({
+        typescript: resolve.sync('typescript', {
+          basedir: paths.appNodeModules,
+        }),
+        async: false,
+        checkSyntacticErrors: true,
+        tsconfig: paths.appTsConfig,
+        compilerOptions: {
+          module: 'esnext',
+          moduleResolution: 'node',
+          resolveJsonModule: true,
+          isolatedModules: true,
+          noEmit: true,
+          jsx: 'preserve',
+        },
+        reportFiles: [
+          '**',
+          '!**/*.json',
+          '!**/__tests__/**',
+          '!**/?(*.)(spec|test).*',
+          '!src/setupProxy.js',
+          '!src/setupTests.*',
+        ],
+        watch: paths.appSrcDemo,
+        silent: true,
+        formatter: typescriptFormatter,
+      }),
+  ].filter(Boolean),
   // 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: {
@@ -275,6 +534,9 @@ module.exports = {
     fs: 'empty',
     net: 'empty',
     tls: 'empty',
-    child_process: 'empty'
-  }
+    child_process: 'empty',
+  },
+  // Turn off performance processing because we utilize
+  // our own hints via the FileSizeReporter
+  performance: false,
 };

config/webpack.config.dev.js

@@ -1,16 +1,23 @@
 'use strict';
 
-const autoprefixer = require('autoprefixer');
+const fs = require('fs');
 const path = require('path');
+const resolve = require('resolve');
 const webpack = require('webpack');
+const PnpWebpackPlugin = require('pnp-webpack-plugin');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
 const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
-const eslintFormatter = require('react-dev-utils/eslintFormatter');
 const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
+const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
 const getClientEnvironment = require('./env');
 const paths = require('./paths');
+const ManifestPlugin = require('webpack-manifest-plugin');
+const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
+const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
+const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
+
 
 // Webpack uses `publicPath` to determine where the app is being served from.
 // In development, we always serve from the root. This makes config easier.
@@ -22,16 +29,60 @@ const publicUrl = '';
 // Get environment variables to inject into our app.
 const env = getClientEnvironment(publicUrl);
 
+// Check if TypeScript is setup
+const useTypeScript = fs.existsSync(paths.appTsConfig);
+
+// style files regexes
+const cssRegex = /\.css$/;
+const cssModuleRegex = /\.module\.css$/;
+const sassRegex = /\.(scss|sass)$/;
+const sassModuleRegex = /\.module\.(scss|sass)$/;
+
+// common function to get style loaders
+const getStyleLoaders = (cssOptions, preProcessor) => {
+  const loaders = [
+    require.resolve('style-loader'),
+    {
+      loader: require.resolve('css-loader'),
+      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: {
+        // Necessary for external CSS imports to work
+        // https://github.com/facebook/create-react-app/issues/2677
+        ident: 'postcss',
+        plugins: () => [
+          require('postcss-flexbugs-fixes'),
+          require('postcss-preset-env')({
+            autoprefixer: {
+              flexbox: 'no-2009',
+            },
+            stage: 3,
+          }),
+        ],
+      },
+    },
+  ];
+  if (preProcessor) {
+    loaders.push(require.resolve(preProcessor));
+  }
+  return loaders;
+};
+
 // This is the development configuration.
 // 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/facebookincubator/create-react-app/issues/343.
+  // See the discussion in https://github.com/facebook/create-react-app/issues/343
   devtool: 'cheap-module-source-map',
   // These are the "entry points" to our application.
   // This means they will be the "root" imports that are included in JS bundle.
-  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
   entry: [
     // Include an alternative client for WebpackDevServer. A client's job is to
     // connect to WebpackDevServer by a socket and get notified about changes.
@@ -65,29 +116,46 @@ 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: {
+      cacheGroups: {
+        default: false,
+      }
+    },
+    // Keep the runtime chunk seperated to enable long term caching
+    // https://twitter.com/wSokra/status/969679223278505985
+    runtimeChunk: false,
+  },
   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"
     // if there are any conflicts. This matches Node resolution mechanism.
-    // https://github.com/facebookincubator/create-react-app/issues/253
-    modules: ['node_modules', paths.appNodeModules].concat(
+    // https://github.com/facebook/create-react-app/issues/253
+    modules: ['node_modules'].concat(
       // It is guaranteed to exist because we tweak it in `env.js`
       process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
     ),
     // These are the reasonable defaults supported by the Node ecosystem.
     // We also include JSX as a common component filename extension to support
     // some tools, although we do not recommend using it, see:
-    // https://github.com/facebookincubator/create-react-app/issues/290
+    // https://github.com/facebook/create-react-app/issues/290
     // `web` extension prefixes have been added for better support
     // for React Native Web.
-    extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
+    extensions: paths.moduleFileExtensions
+      .map(ext => `.${ext}`)
+      .filter(ext => useTypeScript || !ext.includes('ts')),
     alias: {
-
       // Support React Native Web
       // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
       'react-native': 'react-native-web',
     },
     plugins: [
+      // Adds support for installing with Plug'n'Play, leading to faster installs and adding
+      // guards against forgotten dependencies and such.
+      PnpWebpackPlugin,
       // Prevents users from importing files from outside of src/ (or node_modules/).
       // This often causes confusion because we only process files within src/ with babel.
       // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
@@ -96,24 +164,30 @@ module.exports = {
       new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
     ],
   },
+  resolveLoader: {
+    plugins: [
+      // Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
+      // from the current package.
+      PnpWebpackPlugin.moduleLoader(module),
+    ],
+  },
   module: {
     strictExportPresence: true,
     rules: [
-      // TODO: Disable require.ensure as it's not a standard language feature.
-      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
-      // { parser: { requireEnsure: false } },
+      // Disable require.ensure as it's not a standard language feature.
+      { parser: { requireEnsure: false } },
 
       // First, run the linter.
       // It's important to do this before Babel processes the JS.
       {
-        test: /\.(js|jsx|mjs)$/,
+        test: /\.(js|mjs|jsx)$/,
         enforce: 'pre',
         use: [
           {
             options: {
-              formatter: eslintFormatter,
+              formatter: require.resolve('react-dev-utils/eslintFormatter'),
               eslintPath: require.resolve('eslint'),
-
+              
             },
             loader: require.resolve('eslint-loader'),
           },
@@ -136,16 +210,62 @@ module.exports = {
               name: 'static/media/[name].[hash:8].[ext]',
             },
           },
-          // Process JS with Babel.
+          // Process application JS with Babel.
+          // The preset includes JSX, Flow, and some ESnext features.
           {
-            test: /\.(js|jsx|mjs)$/,
+            test: /\.(js|mjs|jsx|ts|tsx)$/,
             include: paths.appSrc,
             loader: require.resolve('babel-loader'),
             options: {
+              customize: require.resolve(
+                'babel-preset-react-app/webpack-overrides'
+              ),
+              
+              plugins: [
+                [
+                  require.resolve('babel-plugin-named-asset-import'),
+                  {
+                    loaderMap: {
+                      svg: {
+                        ReactComponent: '@svgr/webpack?-prettier,-svgo![path]',
+                      },
+                    },
+                  },
+                ],
+              ],
               // This is a feature of `babel-loader` for webpack (not Babel itself).
               // It enables caching results in ./node_modules/.cache/babel-loader/
               // directory for faster rebuilds.
               cacheDirectory: true,
+              // Don't waste time on Gzipping the cache
+              cacheCompression: false,
+            },
+          },
+          // Process any JS outside of the app with Babel.
+          // Unlike the application JS, we only compile the standard ES features.
+          {
+            test: /\.(js|mjs)$/,
+            exclude: /@babel(?:\/|\\{1,2})runtime/,
+            loader: require.resolve('babel-loader'),
+            options: {
+              babelrc: false,
+              configFile: false,
+              compact: false,
+              presets: [
+                [
+                  require.resolve('babel-preset-react-app/dependencies'),
+                  { helpers: true },
+                ],
+              ],
+              cacheDirectory: true,
+              // Don't waste time on Gzipping the cache
+              cacheCompression: false,
+              
+              // If an error happens in a package, it's possible to be
+              // because it was compiled. Thus, we don't want the browser
+              // debugger to show the original code. Instead, the code
+              // being evaluated would be much more helpful.
+              sourceMaps: false,
             },
           },
           // "postcss" loader applies autoprefixer to our CSS.
@@ -153,37 +273,46 @@ module.exports = {
           // "style" loader turns CSS into JS modules that inject <style> tags.
           // In production, we use a plugin to extract that CSS to a file, but
           // in development "style" loader enables hot editing of CSS.
+          // By default we support CSS Modules with the extension .module.css
           {
-            test: /\.css$/,
-            use: [
-              require.resolve('style-loader'),
+            test: cssRegex,
+            exclude: cssModuleRegex,
+            use: getStyleLoaders({
+              importLoaders: 1,
+            }),
+          },
+          // Adds support for CSS Modules (https://github.com/css-modules/css-modules)
+          // using the extension .module.css
+          {
+            test: cssModuleRegex,
+            use: getStyleLoaders({
+              importLoaders: 1,
+              modules: true,
+              getLocalIdent: getCSSModuleLocalIdent,
+            }),
+          },
+          // Opt-in support for SASS (using .scss or .sass extensions).
+          // Chains the sass-loader with the css-loader and the style-loader
+          // to immediately apply all styles to the DOM.
+          // By default we support SASS Modules with the
+          // extensions .module.scss or .module.sass
+          {
+            test: sassRegex,
+            exclude: sassModuleRegex,
+            use: getStyleLoaders({ importLoaders: 2 }, 'sass-loader'),
+          },
+          // Adds support for CSS Modules, but using SASS
+          // using the extension .module.scss or .module.sass
+          {
+            test: sassModuleRegex,
+            use: getStyleLoaders(
               {
-                loader: require.resolve('css-loader'),
-                options: {
-                  importLoaders: 1,
-                },
+                importLoaders: 2,
+                modules: true,
+                getLocalIdent: getCSSModuleLocalIdent,
               },
-              {
-                loader: require.resolve('postcss-loader'),
-                options: {
-                  // Necessary for external CSS imports to work
-                  // https://github.com/facebookincubator/create-react-app/issues/2677
-                  ident: 'postcss',
-                  plugins: () => [
-                    require('postcss-flexbugs-fixes'),
-                    autoprefixer({
-                      browsers: [
-                        '>1%',
-                        'last 4 versions',
-                        'Firefox ESR',
-                        'not ie < 9', // React doesn't support IE8 anyway
-                      ],
-                      flexbox: 'no-2009',
-                    }),
-                  ],
-                },
-              },
-            ],
+              'sass-loader'
+            ),
           },
           // "file" loader makes sure those assets get served by WebpackDevServer.
           // When you `import` an asset, you get its (virtual) filename.
@@ -192,10 +321,10 @@ module.exports = {
           // that fall through the other loaders.
           {
             // Exclude `js` files to keep "css" loader working as it injects
-            // it's runtime that would otherwise processed through "file" loader.
+            // its runtime that would otherwise be processed through "file" loader.
             // Also exclude `html` and `json` extensions so they get processed
             // by webpacks internal loaders.
-            exclude: [/\.js$/, /\.html$/, /\.json$/],
+            exclude: [/\.(js|mjs|jsx|ts|tsx)$/, /\.html$/, /\.json$/],
             loader: require.resolve('file-loader'),
             options: {
               name: 'static/media/[name].[hash:8].[ext]',
@@ -208,18 +337,19 @@ 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(HtmlWebpackPlugin, env.raw),
+    // This gives some necessary context to module not found errors, such as
+    // the requesting resource.
+    new ModuleNotFoundPlugin(paths.appPath),
     // 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),
@@ -227,12 +357,12 @@ module.exports = {
     new webpack.HotModuleReplacementPlugin(),
     // Watcher doesn't work well if you mistype casing in a path so we use
     // a plugin that prints an error when you attempt to do this.
-    // See https://github.com/facebookincubator/create-react-app/issues/240
+    // See https://github.com/facebook/create-react-app/issues/240
     new CaseSensitivePathsPlugin(),
     // If you require a missing module and then `npm install` it, you still have
     // to restart the development server for Webpack to discover it. This plugin
     // makes the discovery automatic so you don't have to restart.
-    // See https://github.com/facebookincubator/create-react-app/issues/186
+    // See https://github.com/facebook/create-react-app/issues/186
     new WatchMissingNodeModulesPlugin(paths.appNodeModules),
     // Moment.js is an extremely popular library that bundles large locale files
     // by default due to how Webpack interprets its code. This is a practical
@@ -240,7 +370,44 @@ module.exports = {
     // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
     // You can remove this if you don't use Moment.js:
     new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
-  ],
+    // Generate a manifest file which contains a mapping of all asset filenames
+    // to their corresponding output file so that tools can pick it up without
+    // having to parse `index.html`.
+    new ManifestPlugin({
+      fileName: 'asset-manifest.json',
+      publicPath: publicPath,
+    }),
+    // TypeScript type checking
+    useTypeScript &&
+      new ForkTsCheckerWebpackPlugin({
+        typescript: resolve.sync('typescript', {
+          basedir: paths.appNodeModules,
+        }),
+        async: false,
+        checkSyntacticErrors: true,
+        tsconfig: paths.appTsConfig,
+        compilerOptions: {
+          module: 'esnext',
+          moduleResolution: 'node',
+          resolveJsonModule: true,
+          isolatedModules: true,
+          noEmit: true,
+          jsx: 'preserve',
+        },
+        reportFiles: [
+          '**',
+          '!**/*.json',
+          '!**/__tests__/**',
+          '!**/?(*.)(spec|test).*',
+          '!src/setupProxy.js',
+          '!src/setupTests.*',
+        ],
+        watch: paths.appSrc,
+        silent: true,
+        formatter: typescriptFormatter,
+      }),
+  ].filter(Boolean),
+
   // 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: {
@@ -250,10 +417,7 @@ 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,
 };

config/webpack.config.prod.js

@@ -1,15 +1,29 @@
 'use strict';
 
-const autoprefixer = require('autoprefixer');
+const fs = require('fs');
 const path = require('path');
 const webpack = require('webpack');
-const ExtractTextPlugin = require('extract-text-webpack-plugin');
-const eslintFormatter = require('react-dev-utils/eslintFormatter');
+const resolve = require('resolve');
+const PnpWebpackPlugin = require('pnp-webpack-plugin');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const InlineChunkHtmlPlugin = require('react-dev-utils/InlineChunkHtmlPlugin');
+const TerserPlugin = require('terser-webpack-plugin');
+const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+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 ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
+const getCSSModuleLocalIdent = require('react-dev-utils/getCSSModuleLocalIdent');
 const paths = require('./paths');
 const getClientEnvironment = require('./env');
+const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
+const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
+const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 const getPackageJson = require('./getPackageJson');
 
+
 // Webpack uses `publicPath` to determine where the app is being served from.
 // It requires a trailing slash, or the file assets will get an incorrect path.
 const publicPath = paths.servedPath;
@@ -18,6 +32,9 @@ const publicPath = paths.servedPath;
 const shouldUseRelativeAssetPaths = publicPath === './';
 // Source maps are resource heavy and can cause out of memory issue for large source files.
 const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
+// Some apps do not need the benefits of saving a web request, so not inlining the chunk
+// makes for a smoother build process.
+const shouldInlineRuntimeChunk = process.env.INLINE_RUNTIME_CHUNK !== 'false';
 // `publicUrl` is just like `publicPath`, but we will provide it to our app
 // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
 // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
@@ -31,17 +48,14 @@ if (env.stringified['process.env'].NODE_ENV !== '"production"') {
   throw new Error('Production builds must have NODE_ENV=production.');
 }
 
-// Note: defined here because it will be used more than once.
-const cssFilename = 'css/index.css';
+// Check if TypeScript is setup
+const useTypeScript = fs.existsSync(paths.appTsConfig);
 
-// ExtractTextPlugin expects the build output to be flat.
-// (See https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/27)
-// However, our output is structured with css, js and media folders.
-// To have this structure working with relative paths, we have to use custom options.
-const extractTextPluginOptions = shouldUseRelativeAssetPaths
-  ? // Making sure that the publicPath goes back to to build folder.
-    { publicPath: Array(cssFilename.split('/').length).join('../') }
-  : {};
+// style files regexes
+const cssRegex = /\.css$/;
+const cssModuleRegex = /\.module\.css$/;
+const sassRegex = /\.(scss|sass)$/;
+const sassModuleRegex = /\.module\.(scss|sass)$/;
 
 const {
   version,
@@ -61,78 +75,228 @@ const banner = `
   LICENSE file in the root directory of this source tree.
   `;
 
+// common function to get style loaders
+const getStyleLoaders = (cssOptions, preProcessor) => {
+  const loaders = [
+    {
+      loader: MiniCssExtractPlugin.loader,
+      options: Object.assign(
+        {},
+        shouldUseRelativeAssetPaths ? { publicPath: '../../' } : undefined
+      ),
+    },
+    {
+      loader: require.resolve('css-loader'),
+      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: {
+        // Necessary for external CSS imports to work
+        // https://github.com/facebook/create-react-app/issues/2677
+        ident: 'postcss',
+        plugins: () => [
+          require('postcss-flexbugs-fixes'),
+          require('postcss-preset-env')({
+            autoprefixer: {
+              flexbox: 'no-2009',
+            },
+            stage: 3,
+          }),
+        ],
+        sourceMap: shouldUseSourceMap,
+      },
+    },
+  ];
+  if (preProcessor) {
+    loaders.push({
+      loader: require.resolve(preProcessor),
+      options: {
+        sourceMap: shouldUseSourceMap,
+      },
+    });
+  }
+  return loaders;
+};
+
 // This is the production configuration.
 // It compiles slowly and is focused on producing a fast and minimal bundle.
 // The development configuration is different and lives in a separate file.
 module.exports = {
+  mode: 'production',
   // Don't attempt to continue if there are any errors.
   bail: true,
   // We generate sourcemaps in production. This is slow but gives good results.
   // You can exclude the *.map files from the build during deployment.
   devtool: shouldUseSourceMap ? 'source-map' : false,
   // In production, we only want to load the app code.
-  entry: [paths.appLibIndexJs], // CRL: library index file instead of app index
+  entry: [paths.appLibIndexJs],
   output: {
-    // CRL: Updated whole block with library specific info
+    // The build folder.
     path: paths.appBuild,
+    // Generated JS file names (with nested folders).
+    // There will be one main bundle, and one file per asynchronous chunk.
+    // We don't currently advertise code splitting but Webpack supports it.
     filename: 'index.js',
+    chunkFilename: 'index.[chunkhash:8].chunk.js',
+    // We inferred the "public path" (such as / or /my-project) from homepage.
+    publicPath: publicPath,
+    library: "SimpleKeyboard",
     libraryTarget: 'umd',
-    library: 'SimpleKeyboard'
+    umdNamedDefine: true,
+    // Point sourcemap entries to original disk location (format as URL on Windows)
+    devtoolModuleFilenameTemplate: info =>
+      path
+        .relative(paths.appSrcLib, info.absoluteResourcePath)
+        .replace(/\\/g, '/'),
+  },
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        terserOptions: {
+          parse: {
+            // we want terser to parse ecma 8 code. However, we don't want it
+            // to apply any minfication steps that turns valid ecma 5 code
+            // into invalid ecma 5 code. This is why the 'compress' and 'output'
+            // sections only apply transformations that are ecma 5 safe
+            // https://github.com/facebook/create-react-app/pull/4234
+            ecma: 8,
+          },
+          compress: {
+            ecma: 5,
+            warnings: false,
+            // Disabled because of an issue with Uglify breaking seemingly valid code:
+            // https://github.com/facebook/create-react-app/issues/2376
+            // Pending further investigation:
+            // https://github.com/mishoo/UglifyJS2/issues/2011
+            comparisons: false,
+            // Disabled because of an issue with Terser breaking valid code:
+            // https://github.com/facebook/create-react-app/issues/5250
+            // Pending futher investigation:
+            // https://github.com/terser-js/terser/issues/120
+            inline: 2,
+          },
+          mangle: {
+            safari10: true,
+            //keep_classnames: true,
+            //keep_fnames: true,
+            module: true
+          },
+          output: {
+            ecma: 5,
+            comments: false,
+            // Turned on because emoji and regex is not minified properly using default
+            // https://github.com/facebook/create-react-app/issues/2488
+            ascii_only: true,
+          },
+        },
+        // Use multi-process parallel running to improve the build speed
+        // Default number of concurrent runs: os.cpus().length - 1
+        parallel: true,
+        // Enable file caching
+        cache: true,
+        sourceMap: shouldUseSourceMap,
+      }),
+      new webpack.BannerPlugin({ 
+        banner: banner, 
+        entryOnly: true 
+      }),
+      new OptimizeCSSAssetsPlugin({
+        cssProcessorOptions: {
+          parser: safePostCssParser,
+          map: shouldUseSourceMap
+            ? {
+                // `inline: false` forces the sourcemap to be output into a
+                // separate file
+                inline: false,
+                // `annotation: true` appends the sourceMappingURL to the end of
+                // the css file, helping the browser find the sourcemap
+                annotation: true,
+              }
+            : false,
+        },
+      }),
+    ],
+    // 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',
+      cacheGroups: {
+        default: false,
+      }
+    },
+    // Keep the runtime chunk seperated to enable long term caching
+    // https://twitter.com/wSokra/status/969679223278505985
+    runtimeChunk: false,
   },
   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"
     // if there are any conflicts. This matches Node resolution mechanism.
-    // https://github.com/facebookincubator/create-react-app/issues/253
-    modules: ['node_modules', paths.appNodeModules].concat(
+    // https://github.com/facebook/create-react-app/issues/253
+    modules: ['node_modules'].concat(
       // It is guaranteed to exist because we tweak it in `env.js`
       process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
     ),
     // These are the reasonable defaults supported by the Node ecosystem.
     // We also include JSX as a common component filename extension to support
     // some tools, although we do not recommend using it, see:
-    // https://github.com/facebookincubator/create-react-app/issues/290
+    // https://github.com/facebook/create-react-app/issues/290
     // `web` extension prefixes have been added for better support
     // for React Native Web.
-    extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
+    extensions: paths.moduleFileExtensions
+      .map(ext => `.${ext}`)
+      .filter(ext => useTypeScript || !ext.includes('ts')),
     alias: {
-
       // Support React Native Web
       // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
       'react-native': 'react-native-web',
     },
     plugins: [
+      // Adds support for installing with Plug'n'Play, leading to faster installs and adding
+      // guards against forgotten dependencies and such.
+      PnpWebpackPlugin,
       // Prevents users from importing files from outside of src/ (or node_modules/).
       // This often causes confusion because we only process files within src/ with babel.
       // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
       // please link the files into your node_modules/ and let module-resolution kick in.
       // Make sure your source files are compiled, as they will not be processed in any way.
-      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
+      new ModuleScopePlugin(paths.appSrcLib, [paths.appPackageJson]),
+    ],
+  },
+  resolveLoader: {
+    plugins: [
+      // Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
+      // from the current package.
+      PnpWebpackPlugin.moduleLoader(module),
     ],
   },
   module: {
     strictExportPresence: true,
     rules: [
-      // TODO: Disable require.ensure as it's not a standard language feature.
-      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
-      // { parser: { requireEnsure: false } },
+      // Disable require.ensure as it's not a standard language feature.
+      { parser: { requireEnsure: false } },
 
       // First, run the linter.
       // It's important to do this before Babel processes the JS.
       {
-        test: /\.(js|jsx|mjs)$/,
+        test: /\.(js|mjs|jsx)$/,
         enforce: 'pre',
         use: [
           {
             options: {
-              formatter: eslintFormatter,
+              formatter: require.resolve('react-dev-utils/eslintFormatter'),
               eslintPath: require.resolve('eslint'),
-
+              
             },
             loader: require.resolve('eslint-loader'),
           },
         ],
-        include: paths.appLibSrc, // CRL: updated with library src folder
+        include: paths.appSrcLib,
       },
       {
         // "oneOf" will traverse all following loaders until one will
@@ -146,77 +310,129 @@ module.exports = {
             loader: require.resolve('url-loader'),
             options: {
               limit: 10000,
-              name: 'media/[name].[ext]',
+              name: 'static/media/[name].[hash:8].[ext]',
             },
           },
-          // Process JS with Babel.
+          // Process application JS with Babel.
+          // The preset includes JSX, Flow, TypeScript and some ESnext features.
           {
-            test: /\.(js|jsx|mjs)$/,
-            include: paths.appLibSrc, // CRL: updated with library src folder
+            test: /\.(js|mjs|jsx|ts|tsx)$/,
+            include: paths.appSrcLib,
+
             loader: require.resolve('babel-loader'),
             options: {
-
+              customize: require.resolve(
+                'babel-preset-react-app/webpack-overrides'
+              ),
+              
+              plugins: [
+                [
+                  require.resolve('babel-plugin-named-asset-import'),
+                  {
+                    loaderMap: {
+                      svg: {
+                        ReactComponent: '@svgr/webpack?-prettier,-svgo![path]',
+                      },
+                    },
+                  },
+                ],
+              ],
+              cacheDirectory: true,
+              // Save disk space when time isn't as important
+              cacheCompression: true,
               compact: true,
             },
           },
-          // The notation here is somewhat confusing.
+          // Process any JS outside of the app with Babel.
+          // Unlike the application JS, we only compile the standard ES features.
+          {
+            test: /\.(js|mjs)$/,
+            exclude: /@babel(?:\/|\\{1,2})runtime/,
+            loader: require.resolve('babel-loader'),
+            options: {
+              babelrc: false,
+              configFile: false,
+              compact: false,
+              presets: [
+                [
+                  require.resolve('babel-preset-react-app/dependencies'),
+                  { helpers: true },
+                ],
+              ],
+              cacheDirectory: true,
+              // Save disk space when time isn't as important
+              cacheCompression: true,
+              
+              // If an error happens in a package, it's possible to be
+              // because it was compiled. Thus, we don't want the browser
+              // debugger to show the original code. Instead, the code
+              // being evaluated would be much more helpful.
+              sourceMaps: false,
+            },
+          },
           // "postcss" loader applies autoprefixer to our CSS.
           // "css" loader resolves paths in CSS and adds assets as dependencies.
-          // "style" loader normally turns CSS into JS modules injecting <style>,
-          // but unlike in development configuration, we do something different.
-          // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
-          // (second argument), then grabs the result CSS and puts it into a
-          // separate file in our build process. This way we actually ship
-          // a single CSS file in production instead of JS code injecting <style>
-          // tags. If you use code splitting, however, any async bundles will still
-          // use the "style" loader inside the async code so CSS from them won't be
-          // in the main CSS file.
+          // `MiniCSSExtractPlugin` extracts styles into CSS
+          // files. If you use code splitting, async bundles will have their own separate CSS chunk file.
+          // By default we support CSS Modules with the extension .module.css
           {
-            test: /\.css$/,
-            loader: ExtractTextPlugin.extract(
-              Object.assign(
-                {
-                  fallback: {
-                    loader: require.resolve('style-loader'),
-                    options: {
-                      hmr: false,
-                    },
-                  },
-                  use: [
-                    {
-                      loader: require.resolve('css-loader'),
-                      options: {
-                        importLoaders: 1,
-                        minimize: true,
-                        sourceMap: shouldUseSourceMap,
-                      },
-                    },
-                    {
-                      loader: require.resolve('postcss-loader'),
-                      options: {
-                        // Necessary for external CSS imports to work
-                        // https://github.com/facebookincubator/create-react-app/issues/2677
-                        ident: 'postcss',
-                        plugins: () => [
-                          require('postcss-flexbugs-fixes'),
-                          autoprefixer({
-                            browsers: [
-                              '>1%',
-                              'last 4 versions',
-                              'Firefox ESR',
-                              'not ie < 9', // React doesn't support IE8 anyway
-                            ],
-                            flexbox: 'no-2009',
-                          }),
-                        ],
-                      },
-                    },
-                  ],
-                },
-                extractTextPluginOptions
-              )
+            test: cssRegex,
+            exclude: cssModuleRegex,
+            loader: getStyleLoaders({
+              importLoaders: 1,
+              sourceMap: shouldUseSourceMap,
+            }),
+            // Don't consider CSS imports dead code even if the
+            // containing package claims to have no side effects.
+            // Remove this when webpack adds a warning or an error for this.
+            // See https://github.com/webpack/webpack/issues/6571
+            sideEffects: true,
+          },
+          // Adds support for CSS Modules (https://github.com/css-modules/css-modules)
+          // using the extension .module.css
+          {
+            test: cssModuleRegex,
+            loader: getStyleLoaders({
+              importLoaders: 1,
+              sourceMap: shouldUseSourceMap,
+              modules: true,
+              getLocalIdent: getCSSModuleLocalIdent,
+            }),
+          },
+          // Opt-in support for SASS. The logic here is somewhat similar
+          // as in the CSS routine, except that "sass-loader" runs first
+          // to compile SASS files into CSS.
+          // By default we support SASS Modules with the
+          // extensions .module.scss or .module.sass
+          {
+            test: sassRegex,
+            exclude: sassModuleRegex,
+            loader: getStyleLoaders(
+              {
+                importLoaders: 2,
+                sourceMap: shouldUseSourceMap,
+              },
+              'sass-loader'
+            ),
+            // Don't consider CSS imports dead code even if the
+            // containing package claims to have no side effects.
+            // Remove this when webpack adds a warning or an error for this.
+            // See https://github.com/webpack/webpack/issues/6571
+            sideEffects: true,
+          },
+          // Adds support for CSS Modules, but using SASS
+          // using the extension .module.scss or .module.sass
+          {
+            test: sassModuleRegex,
+            loader: getStyleLoaders(
+              {
+                importLoaders: 2,
+                sourceMap: shouldUseSourceMap,
+                modules: true,
+                getLocalIdent: getCSSModuleLocalIdent,
+              },
+              'sass-loader'
             ),
-            // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
           },
           // "file" loader makes sure assets end up in the `build` folder.
           // When you `import` an asset, you get its filename.
@@ -225,12 +441,12 @@ module.exports = {
           {
             loader: require.resolve('file-loader'),
             // Exclude `js` files to keep "css" loader working as it injects
-            // it's runtime that would otherwise processed through "file" loader.
+            // it's runtime that would otherwise be processed through "file" loader.
             // Also exclude `html` and `json` extensions so they get processed
             // by webpacks internal loaders.
-            exclude: [/\.js$/, /\.html$/, /\.json$/],
+            exclude: [/\.(js|mjs|jsx|ts|tsx)$/, /\.html$/, /\.json$/],
             options: {
-              name: 'media/[name].[ext]',
+              name: 'static/media/[name].[hash:8].[ext]',
             },
           },
           // ** STOP ** Are you adding a new loader?
@@ -240,52 +456,105 @@ module.exports = {
     ],
   },
   plugins: [
+    // Generates an `index.html` file with the <script> injected.
+    /*new HtmlWebpackPlugin({
+      inject: true,
+      template: paths.appHtml,
+      minify: {
+        removeComments: true,
+        collapseWhitespace: true,
+        removeRedundantAttributes: true,
+        useShortDoctype: true,
+        removeEmptyAttributes: true,
+        removeStyleLinkTypeAttributes: true,
+        keepClosingSlash: true,
+        minifyJS: true,
+        minifyCSS: true,
+        minifyURLs: true,
+      },
+    }),*/
+    // Inlines the webpack runtime script. This script is too small to warrant
+    // a network request.
+    shouldInlineRuntimeChunk &&
+      new InlineChunkHtmlPlugin(HtmlWebpackPlugin, [/runtime~.+[.]js/]),
+    // 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 production, it will be an empty string unless you specify "homepage"
+    // in `package.json`, in which case it will be the pathname of that URL.
+    new InterpolateHtmlPlugin(HtmlWebpackPlugin, env.raw),
+    // This gives some necessary context to module not found errors, such as
+    // the requesting resource.
+    new ModuleNotFoundPlugin(paths.appPath),
     // Makes some environment variables available to the JS code, for example:
     // if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
     // It is absolutely essential that NODE_ENV was set to production here.
     // Otherwise React will be compiled in the very slow development mode.
     new webpack.DefinePlugin(env.stringified),
-    // Minify the code.
-    new webpack.optimize.UglifyJsPlugin({
-      compress: {
-        warnings: false,
-        // Disabled because of an issue with Uglify breaking seemingly valid code:
-        // https://github.com/facebookincubator/create-react-app/issues/2376
-        // Pending further investigation:
-        // https://github.com/mishoo/UglifyJS2/issues/2011
-        comparisons: false,
-      },
-      mangle: {
-        safari10: true,
-      },
-      output: {
-        comments: false,
-        // Turned on because emoji and regex is not minified properly using default
-        // https://github.com/facebookincubator/create-react-app/issues/2488
-        ascii_only: true,
-      },
-      sourceMap: shouldUseSourceMap,
-    }),
-    new webpack.BannerPlugin({ 
-      banner: banner, 
-      entryOnly: true 
-    }),
-    // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
-    new ExtractTextPlugin({
-      filename: cssFilename,
+    new MiniCssExtractPlugin({
+      // Options similar to the same options in webpackOptions.output
+      // both options are optional
+      filename: 'css/index.css',
+      chunkFilename: 'css/index.[contenthash:8].chunk.css',
     }),
+    // Generate a manifest file which contains a mapping of all asset filenames
+    // to their corresponding output file so that tools can pick it up without
+    // having to parse `index.html`.
+    /*new ManifestPlugin({
+      fileName: 'asset-manifest.json',
+      publicPath: publicPath,
+    }),*/
     // Moment.js is an extremely popular library that bundles large locale files
     // by default due to how Webpack interprets its code. This is a practical
     // solution that requires the user to opt into importing specific locales.
     // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
     // You can remove this if you don't use Moment.js:
     new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
-  ],
-  // CRL: added externals block for library
-  externals: {
-   'react': 'react',
-   'react-dom': 'react-dom'
-  },
+    // Generate a service worker script that will precache, and keep up to date,
+    // the HTML & assets that are part of the Webpack build.
+    /*new WorkboxWebpackPlugin.GenerateSW({
+      clientsClaim: true,
+      exclude: [/\.map$/, /asset-manifest\.json$/],
+      importWorkboxFrom: 'cdn',
+      navigateFallback: publicUrl + '/index.html',
+      navigateFallbackBlacklist: [
+        // Exclude URLs starting with /_, as they're likely an API call
+        new RegExp('^/_'),
+        // Exclude URLs containing a dot, as they're likely a resource in
+        // public/ and not a SPA route
+        new RegExp('/[^/]+\\.[^/]+$'),
+      ],
+    }),*/
+    // TypeScript type checking
+    fs.existsSync(paths.appTsConfig) &&
+      new ForkTsCheckerWebpackPlugin({
+        typescript: resolve.sync('typescript', {
+          basedir: paths.appNodeModules,
+        }),
+        async: false,
+        checkSyntacticErrors: true,
+        tsconfig: paths.appTsConfig,
+        compilerOptions: {
+          module: 'esnext',
+          moduleResolution: 'node',
+          resolveJsonModule: true,
+          isolatedModules: true,
+          noEmit: true,
+          jsx: 'preserve',
+        },
+        reportFiles: [
+          '**',
+          '!**/*.json',
+          '!**/__tests__/**',
+          '!**/?(*.)(spec|test).*',
+          '!src/setupProxy.js',
+          '!src/setupTests.*',
+        ],
+        watch: paths.appSrcLib,
+        silent: true,
+        formatter: typescriptFormatter,
+      }),
+  ].filter(Boolean),
   // 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: {
@@ -295,4 +564,7 @@ module.exports = {
     tls: 'empty',
     child_process: 'empty',
   },
+  // Turn off performance processing because we utilize
+  // our own hints via the FileSizeReporter
+  performance: false,
 };

config/webpackDevServer.config.js

@@ -1,10 +1,12 @@
 'use strict';
 
 const errorOverlayMiddleware = require('react-dev-utils/errorOverlayMiddleware');
+const evalSourceMapMiddleware = require('react-dev-utils/evalSourceMapMiddleware');
 const noopServiceWorkerMiddleware = require('react-dev-utils/noopServiceWorkerMiddleware');
-const path = require('path');
+const ignoredFiles = require('react-dev-utils/ignoredFiles');
 const config = require('./webpack.config.dev');
 const paths = require('./paths');
+const fs = require('fs');
 
 const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
 const host = process.env.HOST || '0.0.0.0';
@@ -17,8 +19,8 @@ module.exports = function(proxy, allowedHost) {
     // https://medium.com/webpack/webpack-dev-server-middleware-security-issues-1489d950874a
     // However, it made several existing use cases such as development in cloud
     // environment or subdomains in development significantly more complicated:
-    // https://github.com/facebookincubator/create-react-app/issues/2271
-    // https://github.com/facebookincubator/create-react-app/issues/2233
+    // https://github.com/facebook/create-react-app/issues/2271
+    // https://github.com/facebook/create-react-app/issues/2233
     // While we're investigating better solutions, for now we will take a
     // compromise. Since our WDS configuration only serves files in the `public`
     // folder we won't consider accessing them a vulnerability. However, if you
@@ -61,39 +63,42 @@ module.exports = function(proxy, allowedHost) {
     // as we specified in the config. In development, we always serve from /.
     publicPath: config.output.publicPath,
     // WebpackDevServer is noisy by default so we emit custom message instead
-    // by listening to the compiler events with `compiler.plugin` calls above.
+    // by listening to the compiler events with `compiler.hooks[...].tap` calls above.
     quiet: true,
     // Reportedly, this avoids CPU overload on some systems.
-    // https://github.com/facebookincubator/create-react-app/issues/293
+    // https://github.com/facebook/create-react-app/issues/293
     // src/node_modules is not ignored to support absolute imports
-    // https://github.com/facebookincubator/create-react-app/issues/1065
+    // https://github.com/facebook/create-react-app/issues/1065
     watchOptions: {
-      ignored: new RegExp(
-        `^(?!${path
-          .normalize(paths.appSrc + '/')
-          .replace(/[\\]+/g, '\\\\')}).+[\\\\/]node_modules[\\\\/]`,
-        'g'
-      ),
+      ignored: ignoredFiles(paths.appSrc),
     },
     // Enable HTTPS if the HTTPS environment variable is set to 'true'
     https: protocol === 'https',
-    host: host,
+    host,
     overlay: false,
     historyApiFallback: {
       // Paths with dots should still use the history fallback.
-      // See https://github.com/facebookincubator/create-react-app/issues/387.
+      // See https://github.com/facebook/create-react-app/issues/387.
       disableDotRule: true,
     },
     public: allowedHost,
     proxy,
-    before(app) {
+    before(app, server) {
+      if (fs.existsSync(paths.proxySetup)) {
+        // This registers user provided middleware for proxy reasons
+        require(paths.proxySetup)(app);
+      }
+
+      // This lets us fetch source contents from webpack for the error overlay
+      app.use(evalSourceMapMiddleware(server));
       // This lets us open files from the runtime error overlay.
       app.use(errorOverlayMiddleware());
+
       // This service worker file is effectively a 'no-op' that will reset any
       // previous service worker registered for the same host:port combination.
       // We do this in development to avoid hitting the production cache if
       // it used the same host and port.
-      // https://github.com/facebookincubator/create-react-app/issues/2272#issuecomment-302832432
+      // https://github.com/facebook/create-react-app/issues/2272#issuecomment-302832432
       app.use(noopServiceWorkerMiddleware());
     },
   };