Abilities API: Enhance WP_Ability validation for execute_callback and permission_callback.

Abilities API allows for extending WP_Ability by providing ability_class during the ability registration. This is meant to unlock complex abilities holding some sort of state or logic that requires multiple helper methods.
In all of those scenarios you would ovewrite execute or do_execute method.
However, because the check for execute_callback is in constructor, then in order to register an ability with ability_class overwrite, you have to BOTH: provide do_execute and provide a dummy execute_callback. The same need happens for permission_callback.
This commit fixes the issue execute_callback and permission_callback are now optional when a class is provided. 


Props artpi, swissspidy, jorgefilipecosta, mindctrl.
Fixes #64407.

git-svn-id: https://develop.svn.wordpress.org/trunk@61390 602fd350-edb4-49c9-b593-d223f7449a82

Author: jorgefilipecosta

src/wp-includes/abilities-api/class-wp-ability.php

@@ -277,13 +277,15 @@ protected function prepare_properties( array $args ): array {
 			);
 		}
 
-		if ( empty( $args['execute_callback'] ) || ! is_callable( $args['execute_callback'] ) ) {
+		// If we are not overriding `ability_class` parameter during instantiation, then we need to validate the execute_callback.
+		if ( get_class( $this ) === self::class && ( empty( $args['execute_callback'] ) || ! is_callable( $args['execute_callback'] ) ) ) {
 			throw new InvalidArgumentException(
 				__( 'The ability properties must contain a valid `execute_callback` function.' )
 			);
 		}
 
-		if ( empty( $args['permission_callback'] ) || ! is_callable( $args['permission_callback'] ) ) {
+		// If we are not overriding `ability_class` parameter during instantiation, then we need to validate the permission_callback.
+		if ( get_class( $this ) === self::class && ( empty( $args['permission_callback'] ) || ! is_callable( $args['permission_callback'] ) ) ) {
 			throw new InvalidArgumentException(
 				__( 'The ability properties must provide a valid `permission_callback` function.' )
 			);

tests/phpunit/includes/class-tests-custom-ability-class.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * Test custom ability class that extends WP_Ability.
+ *
+ * This class overrides do_execute() and check_permissions() directly,
+ * allowing registration without execute_callback or permission_callback.
+ */
+class Tests_Custom_Ability_Class extends WP_Ability {
+
+	/**
+	 * Custom execute implementation that multiplies instead of adds.
+	 *
+	 * @param mixed $input The input data.
+	 * @return int The result of multiplying a and b.
+	 */
+	protected function do_execute( $input = null ) {
+		return $input['a'] * $input['b'];
+	}
+
+	/**
+	 * Custom permission check that always returns true.
+	 *
+	 * @param mixed $input The input data.
+	 * @return bool Always true.
+	 */
+	public function check_permissions( $input = null ) {
+		return true;
+	}
+}

tests/phpunit/tests/abilities-api/wpAbilitiesRegistry.php

@@ -23,6 +23,8 @@ class Tests_Abilities_API_WpAbilitiesRegistry extends WP_UnitTestCase {
 	 * Set up each test method.
 	 */
 	public function set_up(): void {
+		require_once DIR_TESTDATA . '/../includes/class-tests-custom-ability-class.php';
+
 		parent::set_up();
 
 		$this->registry = new WP_Abilities_Registry();
@@ -257,6 +259,36 @@ public function test_register_incorrect_execute_callback_type() {
 		$this->assertNull( $result );
 	}
 
+	/**
+	 * Should allow ability registration with custom ability_class that overrides do_execute.
+	 *
+	 * @ticket 64407
+	 *
+	 * @covers WP_Abilities_Registry::register
+	 * @covers WP_Ability::prepare_properties
+	 */
+	public function test_register_with_custom_ability_class_without_execute_callback() {
+		// Remove execute_callback and permission_callback since the custom class provides its own implementation.
+		unset( self::$test_ability_args['execute_callback'] );
+		unset( self::$test_ability_args['permission_callback'] );
+
+		self::$test_ability_args['ability_class'] = 'Tests_Custom_Ability_Class';
+
+		$result = $this->registry->register( self::$test_ability_name, self::$test_ability_args );
+
+		$this->assertInstanceOf( WP_Ability::class, $result, 'Should return a WP_Ability instance.' );
+		$this->assertInstanceOf( Tests_Custom_Ability_Class::class, $result, 'Should return an instance of the custom class.' );
+
+		// Verify the custom execute method works.
+		$execute_result = $result->execute(
+			array(
+				'a' => 5,
+				'b' => 3,
+			)
+		);
+		$this->assertSame( 15, $execute_result, 'Custom do_execute should multiply instead of add.' );
+	}
+
 	/**
 	 * Should reject ability registration without an execute callback.
 	 *