const createWatcher = require('connect-chokidar');

const watchMiddleware = createWatcher(`${__dirname}`, {
  // `process.env.NODE_ENV === 'development'` will be used as the default
  // when this is `false`, no file watching will be done and your middleware
  // will be executed with minimal interference
  isDevEnv: process.env.NODE_ENV === 'development',

  // Only the filenames that are in the regexp below will be deleted
  // from `require.cache` when files change
  requireCacheToRemoveRe: /\/src\//,

  // `usePolling: true` is usually necessary with NFS (and, for me, in docker for mac)
  // other `chokidar` opts can also be provided here
  chokidar: {
    usePolling: true,
  },
});

//...

const app = connect(); // or express()

// Now is the trickier bit, you'll have to `require()` all of the files that your
// local middleware or router depend on. This is because if we required it on top,
// the router / middleware would always refer to that instance and there would be
// no way of clearing it.

app.use('/auth', watchMiddleware(() => require('../auth/router')));

app.use(
  '/api',
  watchMiddleware(() => {
    const midA = require('./middlewareA');
    const apiRouter = require('./api/router');
    return [midA, apiRouter];
  }),
);

app.use(
  '/hello',
  watchMiddleware(() => {
    const midA = require('./middlewareA');
    return [
      midA,
      (req, res) => {
        res.end('world');
      },
    ];
  }),
);