Update coupon search to allow searching by code (https://github.com/woocommerce/woocommerce-admin/pull/1800)

* Add coupon code search filtering to REST API

* Use search_code param in coupon search results

* Use search_code param in coupon autocompleter

* Override search param instead of adding search_code param

plugins/woocommerce-admin/includes/api/class-wc-admin-rest-coupons-controller.php

@@ -24,4 +24,70 @@ class WC_Admin_REST_Coupons_Controller extends WC_REST_Coupons_Controller {
 	 */
 	protected $namespace = 'wc/v4';
 
+	/**
+	 * Get the query params for collections.
+	 *
+	 * @return array
+	 */
+	public function get_collection_params() {
+		$params           = parent::get_collection_params();
+		$params['search'] = array(
+			'description'       => __( 'Limit results to coupons with codes matching a given string.', 'woocommerce-admin' ),
+			'type'              => 'string',
+			'validate_callback' => 'rest_validate_request_arg',
+		);
+		return $params;
+	}
+
+
+	/**
+	 * Add coupon code searching to the WC API.
+	 *
+	 * @param WP_REST_Request $request Request data.
+	 * @return array
+	 */
+	protected function prepare_objects_query( $request ) {
+		$args = parent::prepare_objects_query( $request );
+
+		if ( ! empty( $request['search'] ) ) {
+			$args['search'] = $request['search'];
+			$args['s']      = false;
+		}
+
+		return $args;
+	}
+
+	/**
+	 * Get a collection of posts and add the code search option to WP_Query.
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_Error|WP_REST_Response
+	 */
+	public function get_items( $request ) {
+		add_filter( 'posts_where', array( __CLASS__, 'add_wp_query_search_code_filter' ), 10, 2 );
+		$response = parent::get_items( $request );
+		remove_filter( 'posts_where', array( __CLASS__, 'add_wp_query_search_code_filter' ), 10 );
+		return $response;
+	}
+
+	/**
+	 * Add code searching to the WP Query
+	 *
+	 * @param string $where Where clause used to search posts.
+	 * @param object $wp_query WP_Query object.
+	 * @return string
+	 */
+	public static function add_wp_query_search_code_filter( $where, $wp_query ) {
+		global $wpdb;
+
+		$search = $wp_query->get( 'search' );
+		if ( $search ) {
+			$search = $wpdb->esc_like( $search );
+			$search = "'%" . $search . "%'";
+			$where .= ' AND ' . $wpdb->posts . '.post_title LIKE ' . $search;
+		}
+
+		return $where;
+	}
+
 }