Redirect To Post If Search Results Return One Post

redirect-to-post-if-search-results-return-one-post.php

<?php

function my_redirect_single_post() {
    if (is_search()) {
        global $wp_query;
        if ($wp_query->post_count == 1 && $wp_query->max_num_pages == 1) {
            wp_redirect( get_permalink( $wp_query->posts['0']->ID ) );
            exit;
        }
    }
}

add_action('template_redirect', 'my_redirect_single_post');