function isNativeError
Usage in Deno
import { isNativeError } from "node:util/types";
isNativeError(object: unknown): object is Error
Returns true if the value was returned by the constructor of a built-in Error type.
console.log(util.types.isNativeError(new Error())); // true
console.log(util.types.isNativeError(new TypeError())); // true
console.log(util.types.isNativeError(new RangeError())); // true
Subclasses of the native error types are also native errors:
class MyError extends Error {}
console.log(util.types.isNativeError(new MyError())); // true
A value being instanceof a native error class is not equivalent to isNativeError() returning true for that value. isNativeError() returns true for errors
which come from a different realm while instanceof Error returns false for these errors:
import vm from 'node:vm';
const context = vm.createContext({});
const myError = vm.runInContext('new Error()', context);
console.log(util.types.isNativeError(myError)); // true
console.log(myError instanceof Error); // false
Conversely, isNativeError() returns false for all objects which were not
returned by the constructor of a native error. That includes values
which are instanceof native errors:
const myError = { __proto__: Error.prototype };
console.log(util.types.isNativeError(myError)); // false
console.log(myError instanceof Error); // true
object is Error