webpack.config.prod.js

// @remove-on-eject-begin
/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
// @remove-on-eject-end
'use strict';

const path = require('path');
const webpack = require('webpack');
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 getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');

// 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;
// Source maps are resource heavy and can cause out of memory issue for large source files.
const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== '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 = publicPath.slice(0, -1);
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);

// Assert this just to be safe.
// Development builds of React are slow and not intended for production.
if (env.stringified['process.env'].NODE_ENV !== '"production"') {
  throw new Error('Production builds must have NODE_ENV=production.');
}

// 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 = [
    MiniCssExtractPlugin.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,
          }),
        ],
        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.appIndexJs],
  output: {
    // 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: 'static/js/[name].[chunkhash:8].js',
    chunkFilename: 'static/js/[name].[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.appSrc, 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,
          },
          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: {
            // `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,
          },
        },
      }),
    ],
    // 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,
    },
    // 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"
    // if there are any conflicts. This matches Node resolution mechanism.
    // 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/facebook/create-react-app/issues/290
    // `web` extension prefixes have been added for better support
    // for React Native Web.
    extensions: ['.web.js', '.js', '.json', '.web.jsx', '.jsx'],
    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: [
      // 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]),
    ],
  },
  module: {
    strictExportPresence: true,
    rules: [
      // 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)$/,
        enforce: 'pre',
        use: [
          {
            options: {
              formatter: require.resolve('react-dev-utils/eslintFormatter'),
              eslintPath: require.resolve('eslint'),
              // @remove-on-eject-begin
              // TODO: consider separate config for production,
              // e.g. to enable no-console and no-debugger only in production.
              baseConfig: {
                extends: [require.resolve('eslint-config-react-app')],
                settings: { react: { version: '999.999.999' } },
              },
              ignore: false,
              useEslintrc: false,
              // @remove-on-eject-end
            },
            loader: require.resolve('eslint-loader'),
          },
        ],
        include: paths.appSrc,
      },
      {
        // `mjs` support is still in its infancy in the ecosystem, so we don't
        // support it.
        // Modules who define their `browser` or `module` key as `mjs` force
        // the use of this extension, so we need to tell webpack to fall back
        // to auto mode (ES Module interop, allows ESM to import CommonJS).
        test: /\.mjs$/,
        include: /node_modules/,
        type: 'javascript/auto',
      },
      {
        // "oneOf" will traverse all following loaders until one will
        // match the requirements. When no loader matches it will fall
        // back to the "file" loader at the end of the loader list.
        oneOf: [
          // "url" loader works just like "file" loader but it also embeds
          // assets smaller than specified size as data URLs to avoid requests.
          {
            test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
            loader: require.resolve('url-loader'),
            options: {
              limit: 10000,
              name: 'static/media/[name].[hash:8].[ext]',
            },
          },
          // Process application JS with Babel.
          // The preset includes JSX, Flow, and some ESnext features.
          {
            test: /\.(js|jsx)$/,
            include: paths.appSrc,
            use: [
              // This loader parallelizes code compilation, it is optional but
              // improves compile time on larger projects
              {
                loader: require.resolve('thread-loader'),
                options: {
                  // Forwards the process args (such as --require) to the child
                  // workers. Ensures that the worker operates in the same kind
                  // of environment than the current one (important in case a
                  // preloaded script modifies the env)
                  workerNodeArgs: process.execArgv,
                },
              },
              {
                // We need to use our own loader until `babel-loader` supports
                // customization
                // https://github.com/babel/babel-loader/pull/687
                loader: require.resolve('babel-loader'),
                options: {
                  customize: require.resolve(
                    'babel-preset-react-app/webpack-overrides'
                  ),
                  // @remove-on-eject-begin
                  babelrc: false,
                  configFile: false,
                  presets: [require.resolve('babel-preset-react-app')],
                  // Make sure we have a unique cache identifier, erring on the
                  // side of caution.
                  // We remove this when the user ejects because the default
                  // is sane and uses Babel options. Instead of options, we use
                  // the react-scripts and babel-preset-react-app versions.
                  cacheIdentifier: getCacheIdentifier('production', [
                    'babel-plugin-named-asset-import',
                    'babel-preset-react-app',
                    'react-dev-utils',
                    'react-scripts',
                  ]),
                  // @remove-on-eject-end
                  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$/,
            exclude: /@babel(?:\/|\\{1,2})runtime/,
            use: [
              // This loader parallelizes code compilation, it is optional but
              // improves compile time on larger projects
              {
                loader: require.resolve('thread-loader'),
                options: {
                  // Forwards the process args (such as --require) to the child
                  // workers. Ensures that the worker operates in the same kind
                  // of environment than the current one (important in case a
                  // preloaded script modifies the env)
                  workerNodeArgs: process.execArgv,
                },
              },
              {
                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,
                  // @remove-on-eject-begin
                  cacheIdentifier: getCacheIdentifier('production', [
                    'babel-plugin-named-asset-import',
                    'babel-preset-react-app',
                    'react-dev-utils',
                    'react-scripts',
                  ]),
                  // @remove-on-eject-end
                  // 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.
          // `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: cssRegex,
            exclude: cssModuleRegex,
            loader: getStyleLoaders({
              importLoaders: 1,
              sourceMap: shouldUseSourceMap,
            }),
          },
          // 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'
            ),
          },
          // 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.
          // This loader doesn't use a "test" so it will catch all modules
          // that fall through the other loaders.
          {
            loader: require.resolve('file-loader'),
            // Exclude `js` files to keep "css" loader working as it injects
            // 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|jsx)$/, /\.html$/, /\.json$/],
            options: {
              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.
    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),
    // 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),
    new MiniCssExtractPlugin({
      // Options similar to the same options in webpackOptions.output
      // both options are optional
      filename: 'static/css/[name].[contenthash:8].css',
      chunkFilename: 'static/css/[name].[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$/),
    // Generate a service worker script that will precache, and keep up to date,
    // the HTML & assets that are part of the Webpack build.
    new WorkboxWebpackPlugin.GenerateSW({
      clientsClaim: true,
      exclude: [/\.map$/, /asset-manifest\.json$/],
      importWorkboxFrom: 'local',
      navigateFallback: publicUrl + '/index.html',
      navigateFallbackBlacklist: [
        // Exclude URLs starting with /_, as they're likely an API call
        new RegExp('^/_'),
        // Exclude URLs containing a dot, as they're likely a resource in
        // public/ and not a SPA route
        new RegExp('/[^/]+\\.[^/]+$'),
      ],
    }),
  ],
  // 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: {
    dgram: 'empty',
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
    child_process: 'empty',
  },
  // Turn off performance processing because we utilize
  // our own hints via the FileSizeReporter
  performance: false,
};