extract helper function for normalization

Author: jorgefilipecosta

src/wp-includes/rest-api/endpoints/class-wp-rest-abilities-v1-list-controller.php

@@ -194,6 +194,27 @@ public function get_item_permissions_check( $request ) {
 		return current_user_can( 'read' );
 	}
 
+	/**
+	 * Normalizes schema empty object defaults.
+	 *
+	 * Converts empty array defaults to objects when the schema type is 'object'
+	 * to ensure proper JSON serialization as {} instead of [].
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param array<string, mixed> $schema The schema array.
+	 * @return array<string, mixed> The normalized schema.
+	 */
+	private function normalize_schema_empty_object_defaults( array $schema ): array {
+		if ( isset( $schema['type'] ) && 'object' === $schema['type'] && isset( $schema['default'] ) ) {
+			$default = $schema['default'];
+			if ( is_array( $default ) && empty( $default ) ) {
+				$schema['default'] = (object) $default;
+			}
+		}
+		return $schema;
+	}
+
 	/**
 	 * Prepares an ability for response.
 	 *
@@ -209,26 +230,11 @@ public function prepare_item_for_response( $ability, $request ) {
 			'label'         => $ability->get_label(),
 			'description'   => $ability->get_description(),
 			'category'      => $ability->get_category(),
-			'input_schema'  => $ability->get_input_schema(),
-			'output_schema' => $ability->get_output_schema(),
+			'input_schema'  => $this->normalize_schema_empty_object_defaults( $ability->get_input_schema() ),
+			'output_schema' => $this->normalize_schema_empty_object_defaults( $ability->get_output_schema() ),
 			'meta'          => $ability->get_meta(),
 		);
 
-		// Convert top-level defaults to an object when its type is object and
-		// they are an empty array so they get serialized as {} instead of [].
-		if ( isset( $data['input_schema']['type'] ) && 'object' === $data['input_schema']['type'] && isset( $data['input_schema']['default'] ) ) {
-			$default = $data['input_schema']['default'];
-			if ( is_array( $default ) && empty( $default ) ) {
-				$data['input_schema']['default'] = (object) $default;
-			}
-		}
-		if ( isset( $data['output_schema']['type'] ) && 'object' === $data['output_schema']['type'] && isset( $data['output_schema']['default'] ) ) {
-			$default = $data['output_schema']['default'];
-			if ( is_array( $default ) && empty( $default ) ) {
-				$data['output_schema']['default'] = (object) $default;
-			}
-		}
-
 		$context = $request['context'] ?? 'view';
 		$data    = $this->add_additional_fields_to_object( $data, $request );
 		$data    = $this->filter_response_by_context( $data, $context );