Fix: Handle WP_Error in transformer Factory gracefully (#2429)

Co-authored-by: Matthias Pfefferle <[email protected]>

Author: obenland

.github/changelog/2429-from-description

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fixed fatal error when transformer Factory receives WP_Error objects.

includes/transformer/class-factory.php

@@ -27,6 +27,11 @@ class Factory {
 	 * @return Base|\WP_Error The transformer to use, or an error.
 	 */
 	public static function get_transformer( $data ) {
+		// Early return for WP_Error objects.
+		if ( \is_wp_error( $data ) ) {
+			return $data;
+		}
+
 		if ( \is_string( $data ) && \filter_var( $data, FILTER_VALIDATE_URL ) ) {
 			$response = Http::get_remote_object( $data );
 

tests/phpunit/tests/includes/class-test-query.php

@@ -122,6 +122,36 @@ public function test_get_activitypub_object_id_for_author() {
 		$this->assertEquals( $author_url, $query->get_activitypub_object_id() );
 	}
 
+	/**
+	 * Test get_activitypub_object_id doesn't fatal when queried object filter returns WP_Error.
+	 *
+	 * @covers ::get_activitypub_object_id
+	 */
+	public function test_get_activitypub_object_id_with_wp_error_from_queried_object_filter() {
+		// Mock a scenario where activitypub_queried_object filter returns WP_Error.
+		$filter_callback = function ( $queried_object ) {
+			// Return WP_Error to simulate an error condition.
+			if ( $queried_object instanceof \WP_Post ) {
+				return new \WP_Error( 'queried_object_error', 'Failed to process queried object' );
+			}
+			return $queried_object;
+		};
+		\add_filter( 'activitypub_queried_object', $filter_callback, 10, 1 );
+
+		Query::get_instance()->__destruct();
+		$this->go_to( \get_permalink( self::$post_id ) );
+		$query = Query::get_instance();
+
+		// This should not cause a fatal error.
+		$result = $query->get_activitypub_object_id();
+
+		// Result should be null when queried object is error.
+		$this->assertNull( $result );
+
+		// Clean up filter.
+		\remove_filter( 'activitypub_queried_object', $filter_callback );
+	}
+
 	/**
 	 * Test get_queried_object method.
 	 *

tests/phpunit/tests/includes/transformer/class-test-factory.php

@@ -267,4 +267,19 @@ public function test_uri_transformation_error() {
 
 		\remove_filter( 'pre_http_request', $fake_request );
 	}
+
+	/**
+	 * Test get_transformer with WP_Error input.
+	 *
+	 * @covers ::get_transformer
+	 */
+	public function test_get_transformer_with_wp_error() {
+		$wp_error = new \WP_Error( 'test_error', 'Test error message' );
+		$result   = Factory::get_transformer( $wp_error );
+
+		// Should return the same WP_Error object.
+		$this->assertWPError( $result );
+		$this->assertEquals( 'test_error', $result->get_error_code() );
+		$this->assertEquals( 'Test error message', $result->get_error_message() );
+	}
 }