Show 0 stars and a call to action if a product has no reviews - for use with Product Reviews Pro

sv_wv_prp_show_0_stars.php

<?php // only use if needed
add_action ( 'woocommerce_before_template_part', function( $template_name ) { 

	global $product;
	if ( $product instanceof WC_Product ) {
		$rating_count = $product->get_rating_count();

		if ( 'single-product/rating.php' == $template_name && 0 === $rating_count ) {

			$label = sprintf( __( 'Rated %s out of 5', 'woocommerce' ), 0 );
			$html  = '<div class="star-rating" role="img" aria-label="' . esc_attr( $label ) . '">' . wc_get_star_rating_html( 0 ) . '</div>';
			echo $html . '<a href="#tab-title-reviews">Leave a review</a>';
		}
	}
} );