AB tests for Self Assessment videos

[davidtrussler]

Trello

This PR adds temporary A/B Tests to 3 pages on government-frontend:

• https://www.gov.uk/stop-being-self-employed
• https://www.gov.uk/pay-self-assessment-tax-bill/pay-weekly-monthly
• https://www.gov.uk/log-in-file-self-assessment-tax-return

N.B. The tests for the pay-weekly-monthly one are currently failing and need more work.

Page	Variation A	Variation B
File your Self Assessment tax return online
Pay your Self Assessment tax bill
Stop being self-employed

[hannako]

Great work David and Anna! This looks good to me. I checked the pages when you published the placeholder strings on integration and used the chrome extension to toggle variants - it all seemed to be working fine.

Before merging, please could you either combine the commits into a single one, or create one commit per AB test - whichever you prefer.

Because I've pushed a commit to fix your failing tests, you might want to get another person to give the work a once over before merging

[richardTowers]

Mostly looks good to me - it's tempting to suggest refactoring out the duplication (e.g. by pulling the placeholders / test names / base paths / dimensions from a config file), but that's a step towards normalising this kind of work, which I'm still reluctant to take. I prefer the more brutalist approach of just repeating the code (for now at least).

The one thing I'm not sure about is whether it's okay to reuse the same "dimension" (47) for all of the tests. I'm told this doesn't make any difference in the GA4 world anyway, but I'd appreciate a steer from a Performance Analyst on whether it would make their lives easier if we used different dimensions for different tests.

[richardTowers]

Turns out we've created a with_variant helper method which does this in a neater way - we could consider using it here

https://github.com/alphagov/govuk_ab_testing/blob/main/README.md#minitest

[davidtrussler]

Mostly looks good to me - it's tempting to suggest refactoring out the duplication (e.g. by pulling the placeholders / test names / base paths / dimensions from a config file), but that's a step towards normalising this kind of work, which I'm still reluctant to take. I prefer the more brutalist approach of just repeating the code (for now at least).

The one thing I'm not sure about is whether it's okay to reuse the same "dimension" (47) for all of the tests. I'm told this doesn't make any difference in the GA4 world anyway, but I'd appreciate a steer from a Performance Analyst on whether it would make their lives easier if we used different dimensions for different tests.

Hello @richardTowers We discussed the dimension earlier - see this thread on Slack, so it seems that it is fine to use the same value for all the tests.

[richardTowers]

Thanks folks! Happy for this to be merged now - because of the if ... @content_item.current_part_body.include?(placeholder) conditional it won't do anything until the placeholder is in place, so we can deploy it everywhere and test in lower environments by updating the content.