shlinkio / shlink-web-client

const fs = require('fs');

const errorOverlayMiddleware = require('react-dev-utils/errorOverlayMiddleware');

const evalSourceMapMiddleware = require('react-dev-utils/evalSourceMapMiddleware');

const noopServiceWorkerMiddleware = require('react-dev-utils/noopServiceWorkerMiddleware');

const ignoredFiles = require('react-dev-utils/ignoredFiles');

const paths = require('./paths');

const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';

const host = process.env.HOST || '0.0.0.0';

module.exports = function(proxy, allowedHost) {

  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.

    disableHostCheck:

      !proxy || process.env.DANGEROUSLY_DISABLE_HOST_CHECK === 'true',

    // Enable gzip compression of generated files.

    compress: true,

    // Silence WebpackDevServer's own logs since they're generally not useful.

    // It will still show compile warnings and errors with this setting.

    clientLogLevel: 'none',

    // 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="shortcut 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.

    contentBase: paths.appPublic,

    // By default files from `contentBase` will not trigger a page reload.

    watchContentBase: true,

    // Enable hot reloading server. It will provide /sockjs-node/ endpoint

    // for the WebpackDevServer client so it can learn when the files were

    // updated. The WebpackDevServer client is included as an entry point

    // in the Webpack development configuration. Note that only changes

    // to CSS are currently hot reloaded. JS changes will refresh the browser.

    hot: true,

    // It is important to tell WebpackDevServer to use the same "root" path

    // as we specified in the config. In development, we always serve from /.

    publicPath: '/',

    // WebpackDevServer is noisy by default so we emit custom message instead

    // 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/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

    watchOptions: {

      ignored: ignoredFiles(paths.appSrc),

    },

    // Enable HTTPS if the HTTPS environment variable is set to 'true'

    https: protocol === 'https',

    host,

    overlay: false,

    historyApiFallback: {

      // Paths with dots should still use the history fallback.

      // See https://github.com/facebook/create-react-app/issues/387.

      disableDotRule: true,

    },

    public: allowedHost,

    proxy,

    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/facebook/create-react-app/issues/2272#issuecomment-302832432

      app.use(noopServiceWorkerMiddleware());

    },

  };

};