SQL: when GROUPed BY, the DAY_NAME function outputs incorrect results

[emasab]

• bugfix for SQL: when GROUPed BY, the DAY_NAME function outputs incorrect results #40241
• added unit test

[elasticmachine]

Pinging @elastic/es-search

[emasab]

hi, could you take a look at the PR?

[astefan]

@emasab I took a look at your PR and then analyzed the issue itself in more depth performing more tests following the investigation. It turned out that DAY_NAME wasn't the only function exhibiting the faulty behavior and a more general fix was needed. As such, I created this PR including a fix. As you can see, more classes needed the change and, also:

• there is existing code that already has most of the functionality that you included in your PR, namely ScriptWeaver interface
• the tests you added should have been placed in a different class - QueryTranslatorTests
• I would have liked to see more integration tests, as well. See my PR with some examples.

We really appreciate you took the time to provide a fix and tests for it (and are looking forward to more PRs), but the actual change needed to fix the issue is quite different than what you have in this PR and, if you don't mind, I'll close your PR.

[emasab]

@astefan I've not tested your PR but given that it's a more complete fix, it's ok to close this one.