utils.js

'use strict'

const Controller = require('trails/controller')
const Policy = require('trails/policy')
const Joi = require('joi')
const methods = require('methods')
const _ = require('lodash')

module.exports = {
  extendsExpressRouter: app => {
    methods.concat('all').forEach(function (method) {
      const originalMethod = app[method]
      app[method] = function (key) {
        const args = [].slice.call(arguments)
        const config = args[1]

        // Check if second argument is the route config object
        if (_.isPlainObject(config)) {
          args[1] = function(req, res, next){
            req.route.config = config
            next()
          }
        }
        return originalMethod.apply(this, args)
      }
    })
  },
  isTrailsStandard: function(obj) {
    const className = obj.constructor.name
    if (className == Controller.name || className == Policy.name) {
      return true
    }
    else if (className == 'Object') {
      return false
    }
    else {
      return this.isTrailsStandard(obj.__proto__)
    }
  },
  /**
   * Transform express request to hapi like request
   * @param req as express
   * @param res as express
   * @returns request hapi like object
   */
  createRequest: function(req, res) {
    return {
      raw: {
        req: req,
        res: res
      },
      params: req.params,
      payload: req.body,
      query: req.query,
      headers: req.headers,
      route: req.route,
      url: req.url
    }
  },
  /**
   * Transform express response to hapi like response
   * @param req as express
   * @param res as express
   * @param next as express
   * @returns  response hapi like object
   */
  createResponse: function(req, res, next) {
    const response = (data) => {

      return new Promise((resolve, reject) => {
        if (!data) {
          next()
        }
        else if (data instanceof Error) {
          if (!data.output) {
            data.output = {}
          }
          const code = data.code || data.output.statusCode
          res.status(code || 500).send(data.message)
        }
        else {
          res.send(data)
        }
        resolve()
      })
    }

    response.continue = () => {
      return new Promise((resolve, reject) => {
        next()
        resolve()
      })
    }
    response.header = (key, value) => {
      return new Promise((resolve, reject) => {
        res.set(key, value)
        resolve()
      })
    }
    return response
  },

  /**
   * Returnn an hapi like validation middleware for epxress
   * @param trails route configuration
   * @returns  Joi validation Rules
   */
  createJoiValidationRules: function(route) {
    if (route.config.validate.payload) {
      route.config.validate.body = route.config.validate.payload // hapi compatibility
    }
    const validation = route.config.validate
    const types = ['headers', 'params', 'query', 'body']
    types.forEach((type) => {
      let rule = validation[type]

      // null, undefined, true - anything allowed
      // false - nothing allowed
      // {...} - ... allowed
      rule = (rule === false ? Joi.object({}).allow(null) :
        typeof rule === 'function' ? rule :
        !rule || rule === true ? Joi.any() :
        Joi.compile(rule))
      validation[type] = rule
    })
    return validation
  }
}