error

@nick/is/error

isError

Signature

function isError(it: unknown): it is Error;

Check if the given value is an instance of the native Error class, or of a subclass that inherits from it, like TypeError or RangeError.

This is more reliable than instanceof Error, because it also works across different realms (e.g. iframes / web workers / browser tabs). It's also more strict than instanceof because it does not recognize objects that were created with Object.create(Error.prototype) or Object.setPrototypeOf as being a subclass of Error.

Parameters

Name	Info
it	The value to check.

Returns

true if the value is an error, false otherwise.

Category

Standard

Examples

import { isError } from "jsr:@nick/is/error";

const err = new Error("Something went wrong");
console.log(isError(err)); // true
console.log(isError(err.message)); // false