ProductQuery.php

<?php
/**
	 * Return a query for product visibility depending on their stock status.
	 *
	 * @param array $stock_query Stock status query.
	 *
	 * @return array Tax query for product visibility.
	 */
	private function get_product_visibility_query( $stock_query, $stock_status ) {
		$product_visibility_terms  = wc_get_product_visibility_term_ids();
		$product_visibility_not_in = array( is_search() ? $product_visibility_terms['exclude-from-search'] : $product_visibility_terms['exclude-from-catalog'] );

		// Hide out of stock products.
		if ( empty( $stock_query ) && in_array( 'outofstock', $stock_status, true ) ) {
			$product_visibility_not_in[] = $product_visibility_terms['outofstock'];
		}

		return array(
			'tax_query' => array(
				array(
					'taxonomy' => 'product_visibility',
					'field'    => 'term_taxonomy_id',
					'terms'    => $product_visibility_not_in,
					'operator' => 'NOT IN',
				),
			),
		);
	}