Cache Busting and Versioning for rtl.css

Do you load the rtl.css file using the automatic method WordPress provides? That is, adding the rtl.css file to your theme directory so that when the site language is set to right-to-left (RTL), this file loads automatically. It is the preferred way to load RTL-specific CSS for RTL sites.

However, this file has no version (no query string), which makes cache busting difficult in the browser, especially for this file (if you are not using a caching plugin).

To add the ver parameter to the rtl.css file based on when the file was last modified, use the following filter:

add_filter( 'locale_stylesheet_uri', function ($localized_stylesheet_uri) {
    $time_ver = filemtime( get_stylesheet_directory() . '/rtl.css' );
    return add_query_arg( array('ver' => $time_ver), $localized_stylesheet_uri );
});