xk6-faker

Random fake data generator for k6.

Although there are several good JavaScript fake data generators, using these in k6 tests has several disadvantages (download size, memory usage, startup time, etc). The xk6-faker implemented as a golang extension, so tests start faster and use less memory. The price is a little bit smaller feature set compared with popular JavaScript fake data generators.

For convenience, the xk6-faker API resembles the popular Faker.js. The category names and the generator function names are often different (due to the underlying go faker library), but the usage pattern is similar.

Check out the API documentation here. The TypeScript declaration file can be downloaded from here.

Usage

For convenient use, the default export of the module is a Faker instance, it just needs to be imported and it is ready for use.

import faker from "k6/x/faker";

export default function () {
  console.log(faker.person.firstName());
}

// prints a random first name

For a reproducible test run, a random seed value can be passed to the constructor of the Faker class.

import { Faker } from "k6/x/faker";

const faker = new Faker(11);

export default function () {
  console.log(faker.person.firstName());
}

// output: Josiah

Test reproducibility can also be achieved using the default Faker instance, if the seed value is set in the XK6_FAKER_SEED environment variable.

k6 run --env XK6_FAKER_SEED=11 script.js

then

import faker from "k6/x/faker";

export default function () {
  console.log(faker.person.firstName());
}

// as long as XK6_FAKER_SEED is 11
// output: Josiah

The examples directory contains examples of how to use the xk6-faker extension. A k6 binary containing the xk6-faker extension is required to run the examples.

Important

If the search path also contains the k6 command, don't forget to specify which k6 you want to run (for example ./k6).

Download

You can download pre-built k6 binaries from the Releases page.

Build

The xk6 build tool can be used to build a k6 that will include xk6-faker extension:

$ xk6 build --with github.com/grafana/xk6-faker@latest

For more build options and how to use xk6, check out the xk6 documentation.

Feedback

If you find the xk6-faker extension useful, please star the repo. The number of stars will determine the time allocated for maintenance.