Custom Express Responses

custom-express-responses.js

/**
 * Create custom response
 * @param {Object} res - express response object
 * @param {Number} status - status code
 * @param {String} defaultMessage - default response
 * @returns {Function} returns function which access response message
 */
const createResponse = (res, status, defaultMessage) => data => {
  // Set status code
  res.status(status)

  if (typeof data === 'string') {
    return res.json({
      message: data
    })
  }

  return res.json(
    data || {
      message: defaultMessage
    }
  )
}

app.use((req, res, next) => {
  res.notFound = createResponse(res, 404, 'Not Found')
  res.unauthorized = createResponse(res, 401, 'Unauthorized')
  res.badRequest = createResponse(res, 400, 'Bad Request')
  res.serverError = createResponse(res, 500, 'Internal Server Error')
  return next()
})