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Version 0.50.0 release notes

k6 v0.50.0 is here 🎉!

This release:

  • Adds support for uploading files from the browser module.
  • Introduces the options.cloud option.
  • Stabilizes the previously experimental timers module as the k6/timers module.
  • Brings JSON Web Key support to the k6/experimental/webcrypto module.

Breaking changes

  • websockets#60 allows manually setting the name tag, which also overwrites the url tag with the name value. This change makes it consistent with the logic that was implemented in k6 v0.41. Thanks, @mkadirtan for contributing!

Browser APIs to Async

In future releases, we are going to be moving most of the synchronous browser APIs to asynchronous ones (promisifying them). We expect this will affect most of our users, so we are posting this upfront before making the change. Here are the reasons for making this large breaking change:

  1. Most browser APIs use some form of long-running IO operation (networking) to perform the requested action on the web browser against the website under test. We need to avoid blocking JavaScript’s runtime event loop for such operations.
  2. We’re going to add more asynchronous event-based APIs (such as page.on) that our current synchronous APIs would block.
  3. To align with how developers expect to work with JavaScript APIs.
  4. To have better compatibility with Playwright.

You can find a list of all the APIs that we expect to convert to async in a comment in issue browser#428.

Awaiting on something that’s not a thenable just returns that value, which means you can add the await keyword against APIs that will become async to future proof your test scripts.

New features

Add support for uploading files from the browser module browser#1097, browser#1244

You can now upload files using the available input forms on the website under test. The new API is setInputFiles which can be called from a page, frame or elementHandle types. It can upload one or more files encoded in the test script. To upload files from the local file system, work with the experimental fs module.

Expand to see the examples.

For the following examples, we will use the HTML file:

html 
<html>
  <body>
    <form method="POST" action="/upload" enctype="multipart/form-data">
      <input type="file" name="upl" id="upload" multiple />
      <input type="submit" value="Send" />
    </form>
  </body>
</html>

Uploading a file can be achieved with the following script:

js 
// Import the k6 encoder module.
import encoding from 'k6/encoding';
...
export default async function () {
  const page = browser.newPage();

  await page.goto(url)

  // Encode and upload some data into a plain text file called test.txt.
  page.setInputFiles('input[id="upload"]', { name: 'test.txt', mimetype: 'text/plain', buffer: encoding.b64encode('Hello World') })

  // Click on the submit button on the form to upload the file.
  const submitButton = page.locator('input[type="submit"]')
  await Promise.all([page.waitForNavigation(), submitButton.click()])

  page.close();
}

Uploading multiple files can be done with the use of an array:

js 
page.setInputFiles('input[id="upload"]', [
  { name: 'test.txt', mimetype: 'text/plain', buffer: encoding.b64encode('Hello World') },
  {
    name: 'test.json',
    mimetype: 'text/json',
    buffer: encoding.b64encode('{"message": "Hello World"}'),
  },
]);

Thanks to @bandorko! :bow: :tada:

Introducing options.cloud #3348, #3407

In this release, we introduce a new way of defining cloud options. From now on, you can use options.cloud instead of options.ext.loadimpact.

To migrate, you can move the loadimpact object to the root of the options object and rename it to cloud. For example:

JavaScript 
export let options = {
  ext: {
    loadimpact: {
      name: 'Legacy way of defining cloud options',
      projectID: 12345,
    },
  },
};

export let options = {
  cloud: {
    name: 'Current way of defining cloud options',
    projectID: 12345,
  },
};

All scripts with legacy options.ext.loadimpact will continue to function as before. There’s no planned sunset date for the legacy option, but we highly encourage using options.cloud going forward. For more details about cloud options, refer to Cloud options.

Timers API becomes part of the k6 core #3587

With this release, the timers API is no longer experimental and can be imported as k6/timers instead of as k6/experimental/timers. The later will be supported until v0.52.0.

You can also contribute to the discussion on making the current timer exports globally available in #3589, or just give it a :+1:.

JSON Web Key support in k6/experimental/webcrypto module webcrypto#61

The experimental webcrypto module now supports the JSON Web Key (JWK) format, using the importKey and exportKey methods.

This allows you to import and export keys in the JWK format for the supported algorithms.

js 
const generatedKey = await crypto.subtle.generateKey({ name: 'AES-CBC', length: '256' }, true, [
  'encrypt',
  'decrypt',
]);

const exportedKey = await crypto.subtle.exportKey('jwk', generatedKey);

UX improvements and enhancements

Browser Context Isolation browser#1112

With this release, we have overhauled and (tremendously) improved the performance and stability of the browser module. It’s now possible to run tests with a larger number of VUs concurrently without any performance issues. Previously, when running tests with multiple VUs concurrently, each VU’s browser context would attach to the pages from the other VUs’ browser contexts. This led to unexpected behavior and performance issues and, to an extent, reduced the module’s capability to run multi-VU tests.

Bug fixes

  • #3653 fixes a connectivity issue with non-lowercase options.hosts.
  • browser#1215 fixes a data race during logging that panics.
  • browser#1238 fixes fill functionality for textarea. Thanks @bandorko for the fix! :bow: :tada:
  • browser#1242 fixes XPath evaluation on DocumentFragment.

Maintenance and internal improvements

  • webcrypto#62 fixes display error message in the console and does minor maintenance.
  • webcrypto#60 leverages some of the k6 APIs to handle JavaScript operations.
  • webcrypto#59 makes newTestSetup rely on k6’s modulestest.
  • webcrypto#58 addresses linter issues related to repeated static strings.
  • 3633 updates k6 dependencies.