PHPStan: Fix function argument type issues for WP 6.6

[hellofromTonya]

Previously:

• #58852 (6.4)
• #57782 (6.3)
• #51423 (<= 6.2)

Continuation of the the work to fix function argument type issues as reported by PHPStan. These issues are argument types passed to a WP Core and PHP's built-in functions.

The last report was created 3 years ago ​https://gist.github.com/xknown/77f8cbe233da75080d1e9258a8c94f95. A new report should be generated as a starting point what issues remain to be fixed in 6.3.

Goals are to:

• retain the current behavior (i.e. to avoid breaking changes).
• retain the triggering of notice/warning/error, which are clues and indicators (i.e. rather than silently letting the problem propagate downstream).
• gain PHP 8 compatibility.
• ensure code coverage to validate changes.

This ticket is part of the effort to achieve PHP 8+ compatibility.

[swissspidy]

We should really just properly integrate PHPStan into our tooling rather than doing one-off reports every three years.

Aside: why not just rename the existing ticket rather than just closing them without activity & creating a new one.

[swissspidy]

We should really just properly integrate PHPStan into our tooling rather than doing one-off reports every three years.

Looks like there is #52217 for that. Solving that will just make our lives easier going forward as it avoids the need for recurring tickets like this.

[chaion07]

Thanks @hellofromTonya for reporting this. We reviewed this ticket during a recent bug-scrub session and we recommend it would be good to get some movement on the comments about process for PHPStan and this recurring ticket for each cycle, as well as a new PHPStan report (the last one was 3 years ago).

Cheers!

Props to @costdev & @mukesh27

[westonruter]

I've opened #61175 for integrating PHPStan into the core development workflow.

[hellofromTonya]

With #61175 in 6.7 and the last scheduled 6.6 beta released, moving this to 6.7. Likely can be re-evaluated once #61175 is committed.