Product search include categories and tags

add_filter( 'the_posts', function( $posts, $query ) {

	if( ! is_search() || ! is_main_query() || ! $query ) {
		return $posts;
	}

	// Product tags search
	$args = [
		'post_type' => 'product',
		'posts_per_page' => -1,
		'product_tag' => get_search_query(),
		'post__not_in' => wp_list_pluck( $posts, 'ID' ),
	];
	$results = get_posts( $args );

	// Store any new results
	if( $results ) {
		$posts = array_merge( $posts, $results );
		$query->found_posts = sizeof( $posts );
	}

   	// Product categories search
	$args = [
		'post_type' => 'product',
		'posts_per_page' => -1,
		'product_cat' => get_search_query(),
		'post__not_in' => wp_list_pluck( $posts, 'ID' ),
	];
	$results = get_posts( $args );

	// Store any new results
	if( $results ) {
		$posts = array_merge( $posts, $results );
		$query->found_posts = sizeof( $posts );
	}

	// Pass results
	return $posts;

}, 10, 2 );