function types.isNativeError
Usage in Deno
import { types } from "node:util"; const { isNativeError } = 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 falsefor these errors:
const vm = require('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