text: 
  
  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 SWPrecacheWebpackPlugin = require("sw-precache-webpack-plugin");
  const eslintFormatter = require("react-dev-utils/eslintFormatter");
  const ModuleScopePlugin = require("react-dev-utils/ModuleScopePlugin");
  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 === "./";
  // 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.");
  }
  
  // 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: shouldUseSourceMap ? "source-map" : false,
    // 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 (format as URL on Windows)
      devtoolModuleFilenameTemplate: info =>
        path.relative(paths.appSrc, info.absoluteResourcePath).replace(/\\/g, "/")
    },
    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(
        // 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
      // `web` extension prefixes have been added for better support
      // for React Native Web.
      extensions: [".web.js", ".mjs", ".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: [
        // 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 } },
  
        // First, run the linter.
        // It's important to do this before Babel processes the JS.
        // {
        //   test: /\.(js|jsx|mjs)$/,
        //   enforce: 'pre',
        //   use: [
        //     {
        //       options: {
        //         formatter: eslintFormatter,
        //         eslintPath: require.resolve('eslint'),
  
        //       },
        //       loader: require.resolve('eslint-loader'),
        //     },
        //   ],
        //   include: paths.appSrc,
        // },
        {
          // "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 JS with Babel.
            {
              test: /\.(js|jsx|mjs)$/,
              include: paths.appSrc,
              loader: require.resolve("babel-loader"),
              options: {
                compact: true
              }
            },
            // The notation here is somewhat confusing.
            // "postcss" loader applies autoprefixer to our CSS.
            // "css" loader resolves paths in CSS and adds assets as dependencies.
            // "style" loader normally turns CSS into JS modules injecting <style>,
            // but unlike in development configuration, we do something different.
            // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
            // (second argument), then grabs the result CSS and puts it into a
            // separate file in our build process. This way we actually ship
            // a single CSS file in production instead of JS code injecting <style>
            // tags. If you use code splitting, however, any async bundles will still
            // use the "style" loader inside the async code so CSS from them won't be
            // in the main CSS file.
            {
              test: /\.css$/,
              loader: ExtractTextPlugin.extract(
                Object.assign(
                  {
                    fallback: {
                      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`.
            },
            // "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 processed through "file" loader.
              // Also exclude `html` and `json` extensions so they get processed
              // by webpacks internal loaders.
              exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.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: [
      // 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,
          // 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
      }),
      // 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"
      }),
      // Generate a service worker script that will precache, and keep up to date,
      // the HTML & assets that are part of the Webpack build.
      new SWPrecacheWebpackPlugin({
        // By default, a cache-busting query parameter is appended to requests
        // used to populate the caches, to ensure the responses are fresh.
        // If a URL is already hashed by Webpack, then there is no concern
        // about it being stale, and the cache-busting can be skipped.
        dontCacheBustUrlsMatching: /\.\w{8}\./,
        filename: "service-worker.js",
        logger(message) {
          if (message.indexOf("Total precache size is") === 0) {
            // This message occurs for every build and is a bit too noisy.
            return;
          }
          if (message.indexOf("Skipping static resource") === 0) {
            // This message obscures real errors so we ignore it.
            // https://github.com/facebookincubator/create-react-app/issues/2612
            return;
          }
          console.log(message);
        },
        minify: true,
        // For unknown URLs, fallback to the index page
        navigateFallback: publicUrl + "/index.html",
        // Ignores URLs starting from /__ (useful for Firebase):
        // https://github.com/facebookincubator/create-react-app/issues/2237#issuecomment-302693219
        navigateFallbackWhitelist: [/^(?!\/__).*/],
        // Don't precache sourcemaps (they're large) and build asset manifest:
        staticFileGlobsIgnorePatterns: [/\.map$/, /asset-manifest\.json$/]
      }),
      // Moment.js is an extremely popular library that bundles large locale files
      // by default due to how Webpack interprets its code. This is a practical
      // solution that requires the user to opt into importing specific locales.
      // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
      // You can remove this if you don't use Moment.js:
      new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/)
    ],
    // 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"
    }
  };
  