hide wordpress products rating if empty

I want to hide the stars rating below the title on the products where the reviews are empty. I want to hide only the stars without the ability to leave a new review.
I found a similar solution for hiding a different element and tried to adopt it.

I added this using a snippets plugin to add a class “hide-empty-stars” in body_class when the reviews are empty.

function check_for_empty_stars( $classes ) {
    global $product;
    $id = $product->get_id();

    $args = array ('post_type' => 'product', 'post_id' => $id);    
    $comments = get_comments( $args );

    if(empty($comments)) {
        $classes[] = 'hide-empty-stars';
    }

    return $classes;
}
add_filter( 'body_class', 'check_for_empty_stars' );

Then I hide the star-rating class using css

body.hide-empty-stars .star-rating{
    display: none;
}

It works but after a while I get a critical error and the log says that

mod_fcgid: stderr: PHP Fatal error: Uncaught Error: Call to a member function get_id() on null in /var/www/vhosts/my-domain.gr/httpdocs/wp-content/plugins/code-snippets/php/snippet-ops.php(505) : eval()'d code:3

What could cause this? Is there anything wrong in my code?