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Open source

utils

Note

The source code for this library can be found in the grafana/k6-jslib-utils GitHub repository.

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

FunctionDescription
check(val, sets, [tags])Drop-in replacement for check with support for async values.
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 
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://quickpizza.grafana.com/api/users`, {
    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.
}