In T261647#6428437, @Jdlrobson wrote:

I assume this is going to be blocked until T261648 has run. We'll want to move the search into the header and close out that A/B test before running this one. There's no point in analysing this task until that happens.

👍

Last time we did a similar A/B test using this code: https://gerrit.wikimedia.org/r/c/mediawiki/skins/Vector/+/631214/2/includes/FeatureManagement/Requirements/SearchInHeaderRequirement.php

@Jdlrobson mentioned the issue that we discovered around the same user's ID being different across wikis and the user therefore potentially receiving different experiences on different wikis. We can resolve with the following:

$BUCKETS = [
    /* ... */
];

$lookup = CentralIdLookup::factoryNonLocal();
$id = null;
if ( $lookup ) {
  $id = $lookup->centralIdFromLocalUser( $user );
}
// The central ID lookup failed?
if ( !$id ) {
  $id = $user->getId();
}

$bucketIndex = $id % count( $BUCKETS );

FTR the code related to the first A/B test was removed as part of T258116: Post deploy: Move search styles into layout.less (and other places) and remove temporary feature flags.

Change 656966 had a related patch set uploaded (by Phuedx; owner: Phuedx):
[mediawiki/skins/Vector@master] WIP: Add A/B test harness for Core/Vue.js-based search widgets

https://gerrit.wikimedia.org/r/656966

Change 657085 had a related patch set uploaded (by Phuedx; owner: Phuedx):
[mediawiki/skins/Vector@master] Open up search widget treatment A/B test

https://gerrit.wikimedia.org/r/657085

https://gerrit.wikimedia.org/r/656966 adds the A/B test, which is enabled or disabled using the VectorSearchTreatmentABTest config variable. https://gerrit.wikimedia.org/r/657085, a follow-on change, opens up the A/B test to anons without additional delay or significant complexity.

@ovasileva: You've said (and the task's description also says) that this is a nice to have. That second patch demonstrates that this is possible, trivially so. However, we have to change the unit of variance – I think this is the correct term – to the user's session ID. @MNeisler: Would this complicate your analysis?

In T261647#6758180, @phuedx wrote:

https://gerrit.wikimedia.org/r/656966 adds the A/B test, which is enabled or disabled using the VectorSearchTreatmentABTest config variable. https://gerrit.wikimedia.org/r/657085, a follow-on change, opens up the A/B test to anons without additional delay or significant complexity.

@ovasileva: You've said (and the task's description also says) that this is a nice to have. That second patch demonstrates that this is possible, trivially so. However, we have to change the unit of variance – I think this is the correct term – to the user's session ID. @MNeisler: Would this complicate your analysis?

@phuedx Good news! The change to user's session id shouldn't complicate the analysis to calculate the key metrics identified above (search sessions initiated and completed).

In T261647#6759328, @MNeisler wrote:

In T261647#6758180, @phuedx wrote:

https://gerrit.wikimedia.org/r/656966 adds the A/B test, which is enabled or disabled using the VectorSearchTreatmentABTest config variable. https://gerrit.wikimedia.org/r/657085, a follow-on change, opens up the A/B test to anons without additional delay or significant complexity.

@ovasileva: You've said (and the task's description also says) that this is a nice to have. That second patch demonstrates that this is possible, trivially so. However, we have to change the unit of variance – I think this is the correct term – to the user's session ID. @MNeisler: Would this complicate your analysis?

@phuedx Good news! The change to user's session id shouldn't complicate the analysis to calculate the key metrics identified above (search sessions initiated and completed).

Great news!

I've removed the -2 from the second patch. Thanks, @MNeisler!

Change 657085 abandoned by Phuedx:
[mediawiki/skins/Vector@master] Open up search widget treatment A/B test

Reason:

https://gerrit.wikimedia.org/r/657085

Change 656966 merged by jenkins-bot:
[mediawiki/skins/Vector@master] Add search widget treatment A/B test

https://gerrit.wikimedia.org/r/656966

The following are the QA steps that I went through with @Edtadros yesterday:

1. Add the following to your LocalSettings.php:

php,name=/path/to/mediawiki/LocalSettings.php
$wgVectorSearchTreatmentABTest = true;

2. Login to your dev wiki as Admin
3. Observe that:
   1. The magnifying glass is on the right-hand-side of the search widget
   2. The body element doesn't have the skin-vector-search-vue class

1. Login to your dev wiki as a user with an even ID (e.g. Phuedx-test-2 on my dev wiki has an ID of 4)
2. Observer that:
   1. The magnifying glass is on the left-hand-side of the search widget
   2. The body element has the skin-vector-search-vue class

Per the above. Moving this to Ready for Signoff because this can't be QA'd in production until the WVUI library has been deployed (see T271353: Add WVUI as a vendor library in core).

☝️ Per our discussion yesterday, we'll sign this off now and test the change after we've enabled the A/B test on the Beta Cluster.