fail- -err- -.md

title	description	excerpt
fail( [err] )	Throws an error, failing and aborting the current VU script iteration immediately.	Throws an error, failing and aborting the current VU script iteration immediately.

Immediately throw an error, aborting the current script iteration.

fail() is a simple convenience wrapper on top of JavaScript's throw(), because the latter cannot be used as [expr] || throw, which is a convenient way to write k6 test code.

Parameter	Type	Description
err (optional)	string	Error message that gets printed to stderr.

Example

Aborting the current script iteration if a check fails:

import http from 'k6/http';
import { check, fail } from 'k6';

export default function () {
  const res = http.get('https://k6.io');
  if (
    !check(res, {
      'status code MUST be 200': (res) => res.status == 200,
    })
  ) {
    fail('status code was *not* 200');
  }
}