Refactor error handling in REST API run controller

[gziolo]

• Closes Extend error handling for ability schema validation #14.
• Follow-up for dev!: return WP_Error from WP_Ability methods #23

It addresses the following refactoring:

Consider updating WP_Ability to return WP_Error for better error handling which would then simplify and unify the implementation in REST API controller.

This PR standardizes error handling in the REST API abilities run controller by introducing consistent error codes for different types of validation failures and moving validation logic from the REST controller into the core WP_Ability class.

Testing

Run npm run test:php and make sure all tests pass.

[Copilot]

Pull Request Overview

This PR standardizes error handling in the REST API abilities run controller by introducing consistent error codes for different types of validation failures and moving validation logic from the REST controller into the core WP_Ability class.

• Replaced generic REST error codes with specific ability-related error codes for better error identification
• Moved input/output validation from REST controller to WP_Ability class to centralize validation logic
• Updated permission handling to properly propagate input validation errors

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
includes/rest-api/endpoints/class-wp-rest-abilities-run-controller.php	Removed duplicate validation methods and updated error codes for method and permission checks
includes/abilities-api/class-wp-ability.php	Enhanced validation methods to return standardized WP_Error objects and improved error propagation in execute method
tests/unit/rest-api/wpRestAbilitiesRunController.php	Updated test assertions to expect new standardized error codes
tests/unit/abilities-api/wpRegisterAbility.php	Updated test assertions and removed expected incorrect usage warnings

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[justlevine]

Code lgtm and tests passing locally too 🚀

(I know you marked this in-progress, but it looks complete to me 😇)

[gziolo]

I forgot to remove in progress status 😄

Yes, it should be ready to land.