@mantris/appify/src/middlewares/renderer.js

Very opinionated Node.js API boilerplate as module.

'use strict'

const { HttpError } = require('@mantris/commons')

const ERROR_MESSAGE = 'Oh no! Something went wrong on our end.'

/**
 * @param {HttpError} err Error instance.
 * @param {String} environment Environment name.
 * @param {String} genericmessage Generic displayable error message.
 * @returns {String} Displayable error message.
 */
const getMessage = (err, environment, genericmessage) => {
  if (err.status < 500) {
    return err.message
  }

  return environment !== 'production'
    ? err.message
    : genericmessage
}

/**
 * @param   {HttpError} err         Error instance.
 * @param   {String}    environment Environment name.
 * @returns {String|undefined}      Displayable stack.
 */
const getStack = (err, environment) => {
  return err.status >= 500 && environment !== 'production'
    ? err.stack
    : undefined
}

/**
 * @param   {HttpError} err         Error instance.
 * @param   {String}    environment Environment name.
 * @returns {Object[]|undefined}    Displayable stack.
 */
const getDetails = (err) => {
  return err instanceof HttpError.BadRequest || err instanceof HttpError.UnprocessableEntity
    ? err.details
    : undefined
}

/**
 * @params  {String}   environment Current environment name.
 * @returns {Function}             Middleware.
 */
module.exports = (environment) => {
  return (err, req, res, next) => {
    const { code, status } = err
    const stack = getStack(err, environment)
    const message = getMessage(err, environment, ERROR_MESSAGE)
    const details = getDetails(err)

    res
      .status(status)
      .json({ status, error: { code, message, stack, details } })
  }
}