text: // @remove-on-eject-begin
  /**
   * Copyright (c) 2015-present, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under the BSD-style license found in the
   * LICENSE file in the root directory of this source tree. An additional grant
   * of patent rights can be found in the PATENTS file in the same directory.
   */
  // @remove-on-eject-end
  'use strict';
  
  const autoprefixer = require('autoprefixer');
  const path = require('path');
  const webpack = require('webpack');
  const HtmlWebpackPlugin = require('html-webpack-plugin');
  const ExtractTextPlugin = require('extract-text-webpack-plugin');
  const ManifestPlugin = require('webpack-manifest-plugin');
  const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
  const paths = require('./paths');
  const getClientEnvironment = require('./env');
  
  // 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;
  // Some apps do not use client-side routing with pushState.
  // For these, "homepage" can be set to "." to enable relative asset paths.
  const shouldUseRelativeAssetPaths = publicPath === './';
  // `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.');
  }
  
  // Note: defined here because it will be used more than once.
  const cssFilename = 'static/css/[name].[contenthash:8].css';
  
  // 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('../') }
    : {};
  
  // 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 = {
    // 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: 'source-map',
    // In production, we only want to load the polyfills and the app code.
    entry: [require.resolve('./polyfills'), 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
      devtoolModuleFilenameTemplate: info =>
        path.relative(paths.appSrc, info.absoluteResourcePath),
    },
    resolve: {
      // This allows you to set a fallback for where Webpack should look for modules.
      // We read `NODE_PATH` environment variable in `paths.js` and pass paths here.
      // 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(paths.nodePaths),
      // 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
      extensions: ['.js', '.json', '.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',
      },
    },
    // @remove-on-eject-begin
    // Resolve loaders (webpack plugins for CSS, images, transpilation) from the
    // directory of `react-scripts` itself rather than the project directory.
    resolveLoader: {
      modules: [
        paths.ownNodeModules,
        // Lerna hoists everything, so we need to look in our app directory
        paths.appNodeModules,
      ],
    },
    // @remove-on-eject-end
    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: [
            {
              // @remove-on-eject-begin
              // Point ESLint to our predefined config.
              options: {
                // TODO: consider separate config for production,
                // e.g. to enable no-console and no-debugger only in production.
                baseConfig: {
                  extends: ['react-app'],
                },
                useEslintrc: false,
              },
              // @remove-on-eject-end
              loader: 'eslint-loader',
            },
          ],
          include: paths.appSrc,
        },
        // ** ADDING/UPDATING LOADERS **
        // The "url" loader handles all assets unless explicitly excluded.
        // The `exclude` list *must* be updated with every change to loader extensions.
        // When adding a new loader, you must add its `test`
        // as a new entry in the `exclude` list in the "url" loader.
  
        // "file" loader makes sure those assets end up in the `build` folder.
        // When you `import` an asset, you get its filename.
        {
          exclude: [
            /\.html$/,
            /\.(js|jsx)$/,
            /\.css$/,
            /\.json$/,
            /\.bmp$/,
            /\.gif$/,
            /\.jpe?g$/,
            /\.png$/,
          ],
          loader: 'file-loader',
          options: {
            name: 'static/media/[name].[hash:8].[ext]',
          },
        },
        // "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: 'url-loader',
          options: {
            limit: 10000,
            name: 'static/media/[name].[hash:8].[ext]',
          },
        },
        // Process JS with Babel.
        {
          test: /\.(js|jsx)$/,
          include: paths.appSrc,
          loader: 'babel-loader',
          // @remove-on-eject-begin
          options: {
            babelrc: false,
            presets: [require.resolve('babel-preset-react-app')],
          },
          // @remove-on-eject-end
        },
        // The notation here is somewhat confusing.
        // "postcss" loader applies autoprefixer to our CSS.
        // "css" loader resolves paths in CSS and adds assets as dependencies.
        // "style" loader normally turns CSS into JS modules injecting <style>,
        // but unlike in development configuration, we do something different.
        // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
        // (second argument), then grabs the result CSS and puts it into a
        // separate file in our build process. This way we actually ship
        // a single CSS file in production instead of JS code injecting <style>
        // tags. If you use code splitting, however, any async bundles will still
        // use the "style" loader inside the async code so CSS from them won't be
        // in the main CSS file.
        {
          test: /\.css$/,
          loader: ExtractTextPlugin.extract(
            Object.assign(
              {
                fallback: 'style-loader',
                use: [
                  {
                    loader: 'css-loader',
                    options: {
                      importLoaders: 1,
                      minimize: true,
                    },
                  },
                  {
                    loader: 'postcss-loader',
                    options: {
                      ident: 'postcss', // https://webpack.js.org/guides/migrating/#complex-options
                      plugins: () => [
                        autoprefixer({
                          browsers: [
                            '>1%',
                            'last 4 versions',
                            'Firefox ESR',
                            'not ie < 9', // React doesn't support IE8 anyway
                          ],
                        }),
                      ],
                    },
                  },
                ],
              },
              extractTextPluginOptions
            )
          ),
          // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
        },
        // ** STOP ** Are you adding a new loader?
        // Remember to add the new extension(s) to the "url" loader exclusion list.
      ],
    },
    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 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(env.raw),
      // 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,
        },
      }),
      // 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,
        },
        output: {
          comments: false,
        },
        sourceMap: true,
      }),
      // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
      new ExtractTextPlugin({
        filename: cssFilename,
      }),
      // 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',
      }),
    ],
    // 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: {
      fs: 'empty',
      net: 'empty',
      tls: 'empty',
    },
  };
  