Support custom tags in page.goto() and other relevant methods

[mdcruz]

Currently, we have the ability to support custom tags in k6 core when using http.get() or http.post(). This allows us to customise reports, thresholds or other use cases. See the below code snippet for reference.

http.get('https://test.k6.io/contacts.php', {
    tags: { my_custom_tag: 'contacts' },
  });

This is currently not supported in xk6-browser specific methods such as page.goto(). I have a use case where I want to specify different thresholds per pages and the easiest way is to use tags like the one below:

export const options = {
  ...
  thresholds: {
    'browser_dom_content_loaded{customTag:messages}': ['p(90) < 1000'],
    'browser_dom_content_loaded{customTag:news}': ['p(90) < 800'],
    browser_first_contentful_paint: ['max < 1000']
  }
};

export function messages() {
 /// some other code

  page.goto('https://test.k6.io/my_messages.php', {
    // This custom tag doesn't work as expected
    tags: { customTag: 'messages' },
    waitUntil: 'networkidle'
  })
} 

There are other ways of course to specify different thresholds such as filtering it by default tags such as url or the name metric but it would still be nice to support custom tags going forward.

Resources

• https://github.com/grafana/xk6-websockets/pull/28/files
• How to get the storage from lib.State
• How to set from the got JS object
• How to emit metrics with tags

Tasks

Preview Give feedback

1. Support user defined tags in browser APIs as a new option field.
2. Ensure test-wide tags is supported by the browser module.
3. Ensure code defined tags is supported by the browser module.
4. Ensure tagged stages works with the browser module.
5. Define and support system tags.

[fatmaozcelik]

Hi @imiric, it would be really nice to have such improvement. I also saw that it is confusing and difficult to deal with name metrics etc. Is there any decision made or progress on this issue? Thanks for your answer.

[inancgumus]

@ankur22 Is this related to grafana/xk6-browser#371 or already done by it?

[ankur22]

@inancgumus we need to look into this still. It's unrelated to grafana/xk6-browser#371. It is related to tagging metrics with custom tags. At the moment the browser module will tag metrics here, here and here, whereas with this issue it is wanting to add custom tags when working with our APIs e.g. page.goto. I'm not sure what the outcome of tagging page.goto will be though, will it tag only the page.goto related metrics, or all metrics for the page that it navigates to, or are there other options? We need to investigate and compare with k6's approach.