Relevanssi Customcode settings

setup.php

// Enable one letter search
add_filter('relevanssi_block_one_letter_searches', __NAMESPACE__.'\\one_word_searches');

function one_word_searches() {
    return false;
}

// https://www.relevanssi.com/knowledge-base/indexing-product-variation-skus-main-product/
add_filter( 'relevanssi_content_to_index', __NAMESPACE__.'\\rlv_index_variation_skus', 10, 2 );
function rlv_index_variation_skus( $content, $post ) {
    if ( 'product' === $post->post_type ) {
        $args       = array(
            'post_parent'    => $post->ID,
            'post_type'      => 'product_variation',
            'posts_per_page' => -1
        );
        $variations = get_posts( $args );
        if ( ! empty( $variations ) ) {
            foreach ( $variations as $variation ) {
                $sku      = get_post_meta( $variation->ID, '_sku', true );
                $content .= " $sku";
            }
        }
    }
    return $content;
}