Using Custom Errors in Node.js

customErrors.js

/**
 * Using Custom Errors in Node.js
 * http://dustinsenos.com/articles/customErrorsInNode
 */

// Grab the util module that's bundled with Node
var util = require('util')

// Create a new Abstract Error constructor
var AbstractError = function (msg, constr) {
  // If defined, pass the constr property to V8's
  // captureStackTrace to clean up the output
  Error.captureStackTrace(this, constr || this)

  // If defined, store a custom error message
  this.message = msg || 'Error'
}

// Extend our AbstractError from Error
util.inherits(AbstractError, Error)

// Give our Abstract error a name property. Helpful for logging the error later.
AbstractError.prototype.name = 'Abstract Error'

/**
 * Database Error
 * Now that we have an AbstractError class, we can extend it with other custom error classes as we see fit:
 */

var DatabaseError = function (msg) {
  DatabaseError.super_.call(this, msg, this.constructor)
}
util.inherits(DatabaseError, AbstractError)
DatabaseError.prototype.message = 'Database Error'