dragonfly

Tiny error manager for big applications.

Installation

dragonfly is available on npm.

$ npm install dragonfly

Usage

@param {String} name (required)

var dragonfly = require('dragonfly')
  , errs = dragonfly('CustomError');

.define (key)

@param {String} key (required)
@param {String} message
@return {Definition} chainable object

Define a new error pattern that can be constructed from this dragonfly error repository. Returns a definition for chaining. The key does not occur in the constructed error object; it is simply for lookup purposes.

errs.define('not found')
  .message('Resource "#{path}" cannot be found.')
  .set('httpStatus', 404)
  .set('path', '/');

The slug #{path} will be replaced with either the default value or the value defined on construction for that key.

.create (key[, props][, ssf])

@param {String} key (required)
@param {Object|null} template properties to overwrite
@param {Function} start stack function (default: arguments.callee)
@return {Error} newly constructed error based on template

Create an error using the template of a defined error as the basis for the newly constructed error.

var err = errs.create('not found');

Extra properties can also be specified to be merged on to the newly constructed error. These will also be used for any message replacements. Properties that do not have set defaults are also included.

var err = errs.create('not found', { path: '/blog', method: 'GET' });
err.should.have.property('message', 'Resource "/blog" cannot be found.');
err.should.have.property('httpStatus', 404);
err.should.have.property('method', 'GET');

A returned error can also be serialized for rendering in a template or sent over the wire. The .toJSON() method accepts one argument of boolean value indicating whether the stack property should be included (default: true).

var json = err.toJSON(false);
// {
//     name: 'NotFoundError'
//   , message: 'Resource "/blog" cannot be found.'
//   , httpStatus: 404
//   , path: '/blog'
//   , method: 'GET'
// }

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.