Erro guide

This guide explains how to use erro and why you should.

The following guides are also available:

• Migration guide
• Development guide

Installation

npm install --save erro

Usage

You can erro in two ways depending on your preference. It can create custom error classes for you or factory functions.

// file: errors/not-found-error.js
import erro from 'erro'

export default erro.createErrorFactories('NotFoundError')
// or 
export default erro.createErrorClass('NotFoundError')

// file: index.js
import NotFoundError from './errors/not-found-error'

const user = { id: 5, name: 'Mick' }

const message = `User ${user.id} could not be found!`
const context = { user } // Optional context for error handling. 
const original = new Error('404 not found') // Optional original error. 

const error = NotFoundError(message, context, original)
// or 
const error = new NotFoundError(message, context, original)

Benefits

Serialization

Errors constructed with erro have a custom toJSON function that will expose the message, stack and type properties as opposed to standard errors.

Consistency

Errors constructed with erro have a type property that can be used to identify the type of error.

Rethrowing

You can pass the original error when creating an error. Nothing special is done (yet) with the original, it is just attached to the error as error.original to provide extra information when debugging.

try {
    const user = fetchUser(5)
    // ...
} catch (error) {
    throw RequestError('Failed to fetch user.', null, error)
}

Requirements

Version 3 of erro has been compiled for node 4. I could compile a browser version but I need help with how to test erro in all common browsers.

Configuration

There is nothing to configure anymore because message string interpolation is left to the user.

Thanks

This project uses node-package-skeleton as a starting point for package development.