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 iteration.

fail() does not abort the test, nor does it make the test exit with non-0 status. If you are looking to fail the test by halting the execution, use test.abort() instead

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');
  }
}