const withCustomErrorHandler: ErrorRequestHandler = (...) => {...};
  const withAnotherCustomErrorHandler: ErrorRequestHandler = (...) => {...};

  // should always be placed at the very bottom
  app.use(
    // custom 404 error
    wrapper((request) => {
      throw new BadRequest(`Cannot ${request.method} ${request.path}`);
    }),
    // error handlers
    errorHandler(withCustomErrorHandler, withAnotherCustomErrorHandler)
 );

const targetDirectory = path.join(__dirname, './controllers');

app.use(registerControllers(targetDirectory));

const app = express();

app
  .get(
    '/foo',
    wrapper(middlewareThatMightThrowAnError),
    wrapper(function () {
      ...
      if (condition) throw SomeError(message)
      ...
      return 'Hello, World!';
    }, ...)
  );

import { validate, vendors } from '@jmrl23/express-helper';

class UserLoginDto {
  @vendors.classValidator.IsString()
  @vendors.classValidator.Length(1, 30)
  readonly username: string;

  @vendors.classValidator.IsString()
  @vendors.classValidator.Length(1)
  readonly password: string;
}

// usage of `express.json` is required in validating the `request.body`
app.use(express.json());

app.post(
  '/user/login',
  // validate `request.body`
  validate('BODY', UserLoginDto),
  wrapper(function (request) {
    const data = request.body;
    // process data
  }),
);

import { vendors } from '@jmrl23/express-helper';

// use `BadRequest` from package `http-errors`
throw new vendors.httpErrors.BadRequest('LOL');