text: 'use strict';
  
  const fs = require('fs');
  const evalSourceMapMiddleware = require('react-dev-utils/evalSourceMapMiddleware');
  const noopServiceWorkerMiddleware = require('react-dev-utils/noopServiceWorkerMiddleware');
  const ignoredFiles = require('react-dev-utils/ignoredFiles');
  const redirectServedPath = require('react-dev-utils/redirectServedPathMiddleware');
  const paths = require('./paths');
  const getHttpsConfig = require('./getHttpsConfig');
  
  const host = process.env.HOST || '0.0.0.0';
  const sockHost = process.env.WDS_SOCKET_HOST;
  const sockPath = process.env.WDS_SOCKET_PATH; // default: '/ws'
  const sockPort = process.env.WDS_SOCKET_PORT;
  
  module.exports = function (proxy, allowedHost) {
    const disableFirewall =
      !proxy || process.env.DANGEROUSLY_DISABLE_HOST_CHECK === 'true';
    return {
      // WebpackDevServer 2.4.3 introduced a security fix that prevents remote
      // websites from potentially accessing local content through DNS rebinding:
      // https://github.com/webpack/webpack-dev-server/issues/887
      // 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/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
      // use the `proxy` feature, it gets more dangerous because it can expose
      // remote code execution vulnerabilities in backends like Django and Rails.
      // So we will disable the host check normally, but enable it if you have
      // specified the `proxy` setting. Finally, we let you override it if you
      // really know what you're doing with a special environment variable.
      // Note: ["localhost", ".localhost"] will support subdomains - but we might
      // want to allow setting the allowedHosts manually for more complex setups
      allowedHosts: disableFirewall ? 'all' : [allowedHost],
      // Enable gzip compression of generated files.
      compress: true,
      static: {
        // By default WebpackDevServer serves physical files from current directory
        // in addition to all the virtual build products that it serves from memory.
        // This is confusing because those files won’t automatically be available in
        // production build folder unless we copy them. However, copying the whole
        // project directory is dangerous because we may expose sensitive files.
        // Instead, we establish a convention that only files in `public` directory
        // get served. Our build script will copy `public` into the `build` folder.
        // In `index.html`, you can get URL of `public` folder with %PUBLIC_URL%:
        // <link rel="icon" href="%PUBLIC_URL%/favicon.ico">
        // In JavaScript code, you can access it with `process.env.PUBLIC_URL`.
        // Note that we only recommend to use `public` folder as an escape hatch
        // for files like `favicon.ico`, `manifest.json`, and libraries that are
        // for some reason broken when imported through webpack. If you just want to
        // use an image, put it in `src` and `import` it from JavaScript instead.
        directory: paths.appPublic,
        publicPath: [paths.publicUrlOrPath],
        // By default files from `contentBase` will not trigger a page reload.
        watch: {
          // Reportedly, this avoids CPU overload on some systems.
          // https://github.com/facebook/create-react-app/issues/293
          // src/node_modules is not ignored to support absolute imports
          // https://github.com/facebook/create-react-app/issues/1065
          ignored: ignoredFiles(paths.appSrc),
        },
      },
      client: {
        webSocketURL: {
          // Enable custom sockjs pathname for websocket connection to hot reloading server.
          // Enable custom sockjs hostname, pathname and port for websocket connection
          // to hot reloading server.
          hostname: sockHost,
          pathname: sockPath,
          port: sockPort,
        },
        overlay: true,
      },
      devMiddleware: {
        // It is important to tell WebpackDevServer to use the same "publicPath" path as
        // we specified in the webpack config. When homepage is '.', default to serving
        // from the root.
        // remove last slash so user can land on `/test` instead of `/test/`
        publicPath: paths.publicUrlOrPath.slice(0, -1),
      },
  
      https: getHttpsConfig(),
      host,
      historyApiFallback: {
        // Paths with dots should still use the history fallback.
        // See https://github.com/facebook/create-react-app/issues/387.
        disableDotRule: true,
        index: paths.publicUrlOrPath,
      },
      // `proxy` is run between `before` and `after` `webpack-dev-server` hooks
      proxy,
      onBeforeSetupMiddleware(app, server) {
        // Keep `evalSourceMapMiddleware`
        // middlewares before `redirectServedPath` otherwise will not have any effect
        // This lets us fetch source contents from webpack for the error overlay
        app.use(evalSourceMapMiddleware(server));
  
        if (fs.existsSync(paths.proxySetup)) {
          // This registers user provided middleware for proxy reasons
          require(paths.proxySetup)(app);
        }
      },
      onAfterSetupMiddleware(app) {
        // Redirect to `PUBLIC_URL` or `homepage` from `package.json` if url not match
        app.use(redirectServedPath(paths.publicUrlOrPath));
  
        // 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/facebook/create-react-app/issues/2272#issuecomment-302832432
        app.use(noopServiceWorkerMiddleware(paths.publicUrlOrPath));
      },
    };
  };
  