wp-includes/class-wp-theme-json.php:3414Returns the default slugs for all the presets in an associative array whose keys are the preset paths and the leaves is the list of slugs.
$dataarray$node_patharrayarray protected static function get_default_slugs( $data, $node_path ) { $slugs = array(); foreach ( static::PRESETS_METADATA as $metadata ) { $path = $node_path; foreach ( $metadata['path'] as $leaf ) { $path[] = $leaf; } $path[] = 'default'; $preset = _wp_array_get( $data, $path, null ); if ( ! isset( $preset ) ) { continue; } $slugs_for_preset = array(); foreach ( $preset as $item ) { if ( isset( $item['slug'] ) ) { $slugs_for_preset[] = $item['slug']; } } _wp_array_set( $slugs, $metadata['path'], $slugs_for_preset ); } return $slugs; }Introduced in 5.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-theme-json.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.