error-cause-polyfill

Polyfill error.cause.

error.cause is a recent JavaScript feature to wrap errors.

try {
  doSomething()
} catch (cause) {
  throw new Error('message', { cause })
}

Unfortunately, it is not supported in Node <16.9.0, Opera nor Safari <15. This library adds support for it in those environments.

Install

npm install error-cause-polyfill

This package is an ES module and must be loaded using an import or import() statement, not require().

API

polyfill()

Return value: () => void

Modifies the global error types (Error, TypeError, etc.) so they support error.cause. If error.cause is already supported, this is a noop.

import 'error-cause-polyfill/auto'

try {
  doSomething()
} catch (cause) {
  throw new Error('message', { cause })
}

Or alternatively:

import { polyfill } from 'error-cause-polyfill'

polyfill()

try {
  doSomething()
} catch (cause) {
  throw new Error('message', { cause })
}

This returns a function to undo everything.

import { polyfill } from 'error-cause-polyfill'

const undoPolyfill = polyfill()
undoPolyfill()

getErrors()

Return value: object

Returns an object with each error type (Error, TypeError, etc.) but with error.cause support. If error.cause is already supported, this returns the global error types as is.

Unlike polyfill(), this does not modify the global error types.

import { getErrors } from 'error-cause-polyfill'

const Errors = getErrors()

try {
  doSomething()
} catch (cause) {
  throw new Errors.Error('message', { cause })
}

hasSupport()

Return value: boolean

Returns whether the global error types currently support error.cause.

import { hasSupport, polyfill } from 'error-cause-polyfill'

console.log(hasSupport()) // false
polyfill()
console.log(hasSupport()) // true

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!