is-error-instance

Check if a value is an Error instance.

This is like value instanceof Error except it works across realms, such as iframes or Node.js vm.

Example

import isErrorInstance from 'is-error-instance'

isErrorInstance(new Error('')) // true
isErrorInstance('') // false

const CrossRealmError = vm.runInNewContext('Error')
isErrorInstance(new CrossRealmError('')) // true

isErrorInstance(new TypeError('')) // true
isErrorInstance(new AnyOtherError('')) // true

isErrorInstance(new DOMException('')) // true
isErrorInstance(new DOMError('')) // true

isErrorInstance(new Proxy(new Error(''), {})) // true
isErrorInstance(
  new Proxy(new Error(''), {
    getPrototypeOf() {
      throw new Error('')
    },
  }),
) // false

Install

npm install is-error-instance

This package works in both Node.js >=14.18.0 and browsers. It is an ES module and must be loaded using an import or import() statement, not require().

API

isErrorInstance(value)

value any
Return value: boolean

Related projects

• modern-errors: Handle errors in a simple, stable, consistent way
• error-custom-class: Create one error class
• error-class-utils: Utilities to properly create error classes
• error-serializer: Convert errors to/from plain objects
• merge-error-cause: Merge an error with its cause
• normalize-exception: Normalize exceptions/errors
• set-error-class: Properly update an error's class
• set-error-message: Properly update an error's message
• wrap-error-message: Properly wrap an error's message
• set-error-props: Properly update an error's properties
• set-error-stack: Properly update an error's stack
• error-cause-polyfill: Polyfill error.cause
• handle-cli-error: 💣 Error handler for CLI applications 💥
• log-process-errors: Show some ❤ to Node.js process errors
• error-http-response: Create HTTP error responses
• winston-error-format: Log errors with Winston

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!

Changelog

1.5.0

Features

• Improve TypeScript types