Changeset 63299

Timestamp:

08/14/2026 11:17:51 AM (4 hours ago)

Author:

gziolo

Message:

Clone the wrapped builder when cloning WP_AI_Client_Prompt_Builder

WP_AI_Client_Prompt_Builder had no __clone(), so cloning it copied the reference to the wrapped PromptBuilder instead of the builder itself. That builder mutates its own state, so the clone handed to the wp_ai_client_prevent_prompt filter shared its messages and configuration with the original, and a filter could change the prompt that was then sent to the provider, despite the clone being documented as read-only.

Add __clone() so the wrapped builder, and any stored error, are copied too. The bundled client already implements PromptBuilder::__clone() to deep clone messages, model config and request options, it just never ran because only the wrapper was being cloned.

Props bejignesh, gziolo.
Fixes #65782.

Location:

trunk

Files:

• src/wp-includes/ai-client/class-wp-ai-client-prompt-builder.php (modified) (1 diff)
• tests/phpunit/tests/ai-client/wpAiClientPromptBuilder.php (modified) (1 diff)

trunk/src/wp-includes/ai-client/class-wp-ai-client-prompt-builder.php

@@ -227 +227 @@
 
         /**
+         * Clones the wrapped prompt builder alongside this instance.
+         *
+         * The wrapped builder mutates its own state, so without this a clone would
+         * share that state with the original and any change made to one would be
+         * visible in the other.
+         *
+         * @since 7.2.0
+         */
+        public function __clone() {
+                $this->builder = clone $this->builder;
+
+                if ( null !== $this->error ) {
+                        $this->error = clone $this->error;
+                }
+        }
+
+        /**
          * Registers WordPress abilities as function declarations for the AI model.
          *

trunk/tests/phpunit/tests/ai-client/wpAiClientPromptBuilder.php

@@ -2615 +2615 @@
 
         /**
+         * Returns the text of every message part held by a prompt builder.
+         *
+         * @param WP_AI_Client_Prompt_Builder $builder The prompt builder to read.
+         * @return string[] The text of each message part, in order.
+         */
+        private function get_prompt_parts( WP_AI_Client_Prompt_Builder $builder ): array {
+                $wrapped = new ReflectionProperty( WP_AI_Client_Prompt_Builder::class, 'builder' );
+                self::set_accessible( $wrapped );
+                $inner = $wrapped->getValue( $builder );
+
+                $messages = new ReflectionProperty( $inner, 'messages' );
+                self::set_accessible( $messages );
+
+                $parts = array();
+                foreach ( $messages->getValue( $inner ) as $message ) {
+                        foreach ( $message->getParts() as $part ) {
+                                $parts[] = (string) $part->getText();
+                        }
+                }
+
+                return $parts;
+        }
+
+        /**
+         * Tests that a clone does not share the wrapped builder with the original.
+         *
+         * @ticket 65782
+         */
+        public function test_clone_does_not_share_the_wrapped_builder() {
+                $builder = new WP_AI_Client_Prompt_Builder( AiClient::defaultRegistry(), 'Original prompt' );
+                $clone   = clone $builder;
+
+                $wrapped = new ReflectionProperty( WP_AI_Client_Prompt_Builder::class, 'builder' );
+                self::set_accessible( $wrapped );
+
+                $this->assertNotSame(
+                        $wrapped->getValue( $builder ),
+                        $wrapped->getValue( $clone ),
+                        'A clone should wrap its own builder instance'
+                );
+
+                $clone->with_text( 'Added to the clone' );
+
+                $this->assertSame( array( 'Original prompt' ), $this->get_prompt_parts( $builder ), 'Changing the clone should not change the original' );
+        }
+
+        /**
+         * Tests that the clone passed to the prevent prompt filter cannot change the prompt.
+         *
+         * @ticket 65782
+         */
+        public function test_prevent_prompt_filter_cannot_mutate_the_original_prompt() {
+                add_filter(
+                        'wp_ai_client_prevent_prompt',
+                        static function ( $prevent, $builder ) {
+                                $builder->with_text( 'Added by the filter' );
+                                return $prevent;
+                        },
+                        10,
+                        2
+                );
+
+                $builder = new WP_AI_Client_Prompt_Builder( AiClient::defaultRegistry(), 'Original prompt' );
+                $builder->is_supported();
+
+                $this->assertSame( array( 'Original prompt' ), $this->get_prompt_parts( $builder ), 'A filter should not be able to change the prompt' );
+        }
+
+        /**
          * Tests that once in error state, subsequent fluent calls return the same instance.
          *