wp-includes/class-wp-theme-json.php:4760Resolves the values of CSS variables in the given styles.
$theme_jsonWP_Theme_JSONWP_Theme_JSON public static function resolve_variables( $theme_json ) { $settings = $theme_json->get_settings(); $styles = $theme_json->get_raw_data()['styles']; $preset_vars = static::compute_preset_vars( $settings, static::VALID_ORIGINS ); $theme_vars = static::compute_theme_vars( $settings ); $vars = array_reduce( array_merge( $preset_vars, $theme_vars ), function ( $carry, $item ) { $name = $item['name']; $carry[ "var({$name})" ] = $item['value']; return $carry; }, array() ); $theme_json->theme_json['styles'] = self::convert_variables_to_value( $styles, $vars ); return $theme_json; }Introduced in 6.3.0. 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.