Express implHandler

Simple express method implementation script to catch error code 501

This script is useful if you're developing an API with Express or you'd like to set a default 501 error for your actual server endpoints unused verbs.

const implHandler = require('express-implhandler')
 
implHandler(app)

Example of use

Put this inside your API router just before the 404 error catcher.

Root API endpoint (/api/v1) router example:

const express = require('express')
const router = express.Router()
const implHandler = require('express-implhandler')
 
const users = require('./users')
const cars = require('./cars')
 
// define your routes
router.get('/', (req, res) => {
  res.json({
    message: 'Welcome to this awesome API!'
  })
})
 
router.use('/users', users)
router.use('/cars', cars)
 
// catch 501 and forward to error handler
implHandler(router, (req, res, next) => {
  const err = new Error('Not implemented')
 
  err.status = 501
 
  return next(err)
})
 
// catch 404 and forward to error handler
// ...
 
// JSON error middleware
 
module.exports = router

Then if you try to call to your API endpoints with some method not defined you will receive a 501 response code. For example if you try to make a request PUT /api/v1/ the server will return a 501 HTTP code with the next content:

{
  "message": "Not implemented",
  "error": {
    "status": 501
  }
}

Arguments

app or router instance

Your router instance (router) or your app instance (app).

Note: Pay attention that before call this script the router must have the endpoints registered in order to handle them.

middleware (optional)

Default:*

implHandler(app, (req, res, next) => {
  const err = new Error('Not implemented')
 
  err.status = 501
 
  return next(err)
})

You can override the default middleware with one of your preference:

implHandler(app, (req, res, next) => {
  const err = new Error(
    'Method not yet implemented. Please refer to API docs for more info'
  )
 
  err.status = 501
 
  return next(err)
})

Collaborate

Feel free to make pull request or raise issues!

License

MIT