Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Documentationbreadcrumb arrow Grafana k6breadcrumb arrow JavaScript APIbreadcrumb arrow jslibbreadcrumb arrow utils
Open source RSS

utils

The utils module contains number of small utility functions useful in every day load testing.

⭐️ Source code available on GitHub. Please request features and report bugs through GitHub issues.

FunctionDescription
randomIntBetween(min, max)Random integer in a given range
randomItem(array)Random item from a given array
randomString(length, [charset])Random string of a given length, optionally selected from a custom character set
uuidv4()Random UUID v4 in a string representation
findBetween(content, left, right, [repeat])Extract a string between two surrounding strings
normalDistributionStages(maxVUs, durationSeconds, [numberOfStages])Creates stages which will produce a normal distribution (bell-curve) of VUs for a test
getCurrentStageIndexGet the index of the running stage as defined in the stages array options. It can be used only with the executors that support the stages option as ramping-vus or ramping-arrival-rate.
tagWithCurrentStageIndexTag all the generated metrics in the iteration with the index of the current running stage.
tagWithCurrentStageProfileTag all the generated metrics in the iteration with the computed profile for the current running stage.

Simple example

JavaScript
JavaScript 
import { sleep } from 'k6';
import http from 'k6/http';

import {
  randomIntBetween,
  randomString,
  randomItem,
  uuidv4,
  findBetween,
} from 'https://jslib.k6.io/k6-utils/1.4.0/index.js';

export default function () {
  const res = http.post(`https://test-api.k6.io/user/register/`, {
    first_name: randomItem(['Joe', 'Jane']), // random name
    last_name: `Jon${randomString(1, 'aeiou')}s`, //random character from given list
    username: `user_${randomString(10)}@example.com`, // random email address,
    password: uuidv4(), // random password in form of uuid
  });

  // find a string between two strings to grab the username:
  const username = findBetween(res.body, '"username":"', '"');
  console.log('username from response: ' + username);

  sleep(randomIntBetween(1, 5)); // sleep between 1 and 5 seconds.
}