npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

error-class-utils

v4.0.0

Published

Properly create error classes

Downloads

33,383

Readme

Node Browsers TypeScript Codecov Minified size Mastodon Medium

Properly create error classes.

Useful utilities when creating custom error classes.

Hire me

Please reach out if you're looking for a Node.js API or CLI engineer (11 years of experience). Most recently I have been Netlify Build's and Netlify Plugins' technical lead for 2.5 years. I am available for full-time remote positions.

Features

Example

import {
  ensureCorrectClass,
  ponyfillCause,
  setErrorName,
} from 'error-class-utils'

export class CustomError extends Error {
  constructor(message, parameters) {
    super(message, parameters)

    // Fix some issues when `Error` has been polyfilled
    ensureCorrectClass(this, new.target)

    // Ponyfill `error.cause` on old Node.js/browsers
    ponyfillCause(this, parameters)
  }
}

// Properly set `error.name` as a non-enumerable and inherited property
setErrorName(CustomError, 'CustomError')
import { CustomError } from './errors.js'

const cause = new Error('innerMessage')
const error = new CustomError('message', { cause })
console.log(error instanceof CustomError) // true
console.log(error.name) // 'CustomError'
console.log(error.cause) // Error: innerMessage ...

Install

npm install error-class-utils

This package works in both Node.js >=18.18.0 and browsers.

This is an ES module. It must be loaded using an import or import() statement, not require(). If TypeScript is used, it must be configured to output ES modules, not CommonJS.

API

ensureCorrectClass(error, new.target)

error Error
new.target typeof Error
Return value: void

Some Error polyfills (such as es-shims/error-cause) prevent extending from it. This fixes it.

The second argument must be new.target. This must be called directly inside a class constructor, after super(message, parameters).

import { ensureCorrectClass } from 'error-class-utils'

class CustomError extends Error {
  constructor(message, parameters) {
    super(message, parameters)
    ensureCorrectClass(this, new.target)
  }
}

// Thanks to `ensureCorrectClass()`, this is now always true even when
// `Error` has been polyfilled
console.log(new CustomError('message') instanceof CustomError) // true

ponyfillCause(error, parameters?)

error Error
parameters ErrorParams?
Return value: void

Ponyfills error.cause on older Node.js and browsers.

This must be called inside a class constructor, after super(message, parameters).

import { ponyfillCause } from 'error-class-utils'

class CustomError extends Error {
  constructor(message, parameters) {
    super(message, parameters)
    ponyfillCause(this, parameters)
  }
}

try {
  throw new Error('innerMessage')
} catch (cause) {
  // Works on any platforms thanks to ponyfill
  const error = new CustomError('message', { cause })
  console.log(error.cause.message) // 'innerMessage'
}

setErrorName(ErrorClass, name)

ErrorClass typeof Error
name string
Return value: void

Set an ErrorClass's name.

This must be performed on an error class, not instance. Unlike setting this.name = '...' inside an error's constructor, this follows the native Error classes' pattern where error.name:

import { setErrorName } from 'error-class-utils'

class CustomError extends Error {}
setErrorName(CustomError, 'CustomError')

console.log(CustomError.name) // 'CustomError'
console.log(CustomError.prototype.name) // 'CustomError'

const error = new CustomError('message')
console.log(error.name) // 'CustomError'
console.log(Object.keys(error).includes('name')) // false

Related projects

Support

For any question, don't hesitate to submit an issue on GitHub.

Everyone is welcome regardless of personal background. We enforce a Code of conduct in order to promote a positive and inclusive environment.

Contributing

This project was made with ❤️. The simplest way to give back is by starring and sharing it online.

If the documentation is unclear or has a typo, please click on the page's Edit button (pencil icon) and suggest a correction.

If you would like to help us fix a bug or add a new feature, please check our guidelines. Pull requests are welcome!