error-class

Error Class

This module provides typed errors that closely emulate the native Error class to a pedantic degree.

$ npm install error-class

Usage

The default export is a function that accepts two arguments, the name of the typed error, and an optional function which gets invoked in the context of the error instance with the error arguments after the error setup is completed.

import errorClass from 'error-class'

const SpecialError = errorClass('SpecialError', function () {
  if (arguments.length > 1) this.specialProperty = arguments[1]
})

const instance = new SpecialError('baz', { foo: 'bar' })
instance.message // 'baz'
instance.specialProperty // { foo: 'bar' }

Details

import errorClass from 'error-class'

const HumanError = errorClass('HumanError')

const hungryError = new HumanError(`I'm hungry!`)
hungryError.name // 'HumanError'
hungryError.message // `I'm hungry!`
hungryError.stack // Platform-specific error stack trace.
hungryError.hasOwnProperty('name') // false (!)
hungryError.hasOwnProperty('message') // true
hungryError.hasOwnProperty('stack') // true


// Just like native errors, it doesn't require using `new`.
const thirstyError = HumanError(`I'm thirsty!`)
Object.keys(thirstyError).length === 0 // True, all properties are non-enumerable.
Object.keys(Object.getPrototypeOf(instance)).length === 0 // Prototype non-enumerable.
thirstyError.constructor === HumanError // True.
thirstyError.constructor.name === 'HumanError' // True.
thirstyError instanceof Error // True, errors inherit from native `Error` class.
thirstyError instanceof HumanError // Also true, of course.

License

This software is licensed under the MIT License.