errorhandler

Development-only error handler middleware

errorhandler

Development-only error handler middleware

$ npm install errorhandler
var errorhandler = require('errorhandler')

Create new middleware to handle errors and respond with content negotiation. This middleware is only intended to be used in a development environment, as the full error stack traces will be sent back to the client when an error occurs.

Error handler accepts these properties in the options object.

Provide a function to be called with the error and a string representation of the error. Can be used to write the error to any desired location, or set to false to only send the error back in the response. Called as log(err, str, req, res) where err is the Error object, str is a string representation of the error, req is the request object and res is the response object (note, this function is invoked after the response has been written).

The default value for this option is true unless process.env.NODE_ENV === 'test'.

Possible values:

  • true: Log errors using console.error(str).
  • false: Only send the error back in the response.
  • A function: pass the error to a function for handling.

Basic example of adding this middleware as the error handler only in development with connect (express also can be used in this example).

var connect = require('connect')
var errorhandler = require('errorhandler')
 
var app = connect()
 
if (process.env.NODE_ENV === 'development') {
  // only use in development 
  app.use(errorhandler())
}

Sometimes you may want to output the errors to a different location than STDERR during development, like a system notification, for example.

var connect = require('connect')
var errorhandler = require('errorhandler')
var notifier = require('node-notifier')
 
var app = connect()
 
if (process.env.NODE_ENV === 'development') {
  // only use in development 
  app.use(errorhandler({log: errorNotification}))
}
 
function errorNotification(errstrreq) {
  var title = 'Error in ' + req.method + ' ' + req.url
 
  notifier.notify({
    title: title,
    message: str
  })
}

MIT