PHPCS/Psalm: Figure out how to reconcile $_unused_ var name prefixes in child classes with Psalm static analysis

[reykjalin]

Description

While working on #8955 @timur27 found that using the suggested $_unused_ prefix in child classes results in Psalm reporting an issue due to a parameter name mismatch (see #8955 (comment)).

Expected behavior

You should be able to use the $_unused_ prefix to explicitly mark function parameters as unused, even in child classes, without generating further errors during static analysis.

Actual behavior

Psalm reports an issue due to a mismatch in parent function parameter names and the child implementation.

[anu-rock]

This issue is about product architecture & common problems. Sending it to @Automattic/transact-architecture (ping @jrodger) as per our product responsibilities Pc2DNy-3z-p2.

[marcinbot]

See the comment here: #8955 (comment)

The sniffer's behaviour is correct. It highlights a problem with the class structure that we've come to rely on.

I'll close this in favor of V2 - hopefully this will be less prevalent there with more thought-through approaches.

[reykjalin]

Thanks for jumping in here so quickly @marcinbot 🙌