@berun/runner-webpack/src/runner-devserver.ts

Webpack runner for building React web applications

import * as errorOverlayMiddleware from 'react-dev-utils/errorOverlayMiddleware'
import * as evalSourceMapMiddleware from 'react-dev-utils/evalSourceMapMiddleware'
import * as noopServiceWorkerMiddleware from 'react-dev-utils/noopServiceWorkerMiddleware'
import * as ignoredFiles from 'react-dev-utils/ignoredFiles'
import {
  prepareProxy,
  prepareUrls
} from 'react-dev-utils/WebpackDevServerUtils'
import Berun from '@berun/berun'

export default (berun: Berun, opts = {}) => {
  const options = Object.assign(berun.options, opts)

  const proxySetting = require(options.paths.appPackageJson).proxy
  const proxyConfig = prepareProxy(proxySetting, options.paths.appPublic)

  const protocol = process.env.HTTPS === 'true' ? 'https' : 'http'
  const HOST = process.env.HOST || '0.0.0.0'

  const urls = prepareUrls(protocol, HOST, 0)

  berun.devserver.merge({
    // 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:
      !proxyConfig || process.env.DANGEROUSLY_DISABLE_HOST_CHECK === 'true',
    https: protocol === 'https',
    host: HOST,
    public: urls.lanUrlForConfig,
    proxy: proxyConfig,
    // 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: options.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: berun.webpack.output.get('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(options.paths.appSrc)
    },
    overlay: false,
    historyApiFallback: {
      // Paths with dots should still use the history fallback.
      // See https://github.com/facebook/create-react-app/issues/387.
      disableDotRule: true
    },
    before(app, server) {
      // 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())
    }
  }) // merge
} // middleware exports