From 9724b67ab8ae4f27e28042471805a1720e1bcfe3 Mon Sep 17 00:00:00 2001
From: Justin Shreve <justin.shreve@gmail.com>
Date: Thu, 9 Mar 2017 13:36:23 -0800
Subject: [PATCH] Fix order item meta functions cache busting.

The cache busting currently in `wc_add_order_item_meta`, `wc_update_order_item_meta`, and `wc_delete_order_item_meta` doesn't actually bust anything. The cache line looks like it is from 2.6. The relevent cache to bust is actually in the `order-items` group and has a different key/prefix.
This bug allows your meta to get out of sync if you use these functions and then try to access a value from a CRUD object.

You can see this in the `test_wc_order_item_meta_functions` test I've added. If you keep your `wc-order-item-functions.php` as is, the asserts against `$item->get_meta` will fail.

To test:
* `phpunit --filter=test_wc_order_item_meta_functions`.
* Try before applying the `wc-order-item-functions.php` changes and after.
---
 includes/wc-order-item-functions.php       | 12 ++---
 tests/unit-tests/order-items/functions.php | 62 ++++++++++++++++++++++
 2 files changed, 68 insertions(+), 6 deletions(-)
 create mode 100644 tests/unit-tests/order-items/functions.php

diff --git a/includes/wc-order-item-functions.php b/includes/wc-order-item-functions.php
index 4666541ca4d..368008ed1bb 100644
--- a/includes/wc-order-item-functions.php
+++ b/includes/wc-order-item-functions.php
@@ -98,8 +98,8 @@ function wc_delete_order_item( $item_id ) {
 function wc_update_order_item_meta( $item_id, $meta_key, $meta_value, $prev_value = '' ) {
 	$data_store = WC_Data_Store::load( 'order-item' );
 	if ( $data_store->update_metadata( $item_id, $meta_key, $meta_value, $prev_value ) ) {
-		$cache_key = WC_Cache_Helper::get_cache_prefix( 'orders' ) . 'item_meta_array_' . $item_id;
-		wp_cache_delete( $cache_key, 'orders' );
+		$cache_key = WC_Cache_Helper::get_cache_prefix( 'order-items' ) . 'object_meta_' . $item_id;
+		wp_cache_delete( $cache_key, 'order-items' );
 		return true;
 	}
 	return false;
@@ -118,8 +118,8 @@ function wc_update_order_item_meta( $item_id, $meta_key, $meta_value, $prev_valu
 function wc_add_order_item_meta( $item_id, $meta_key, $meta_value, $unique = false ) {
 	$data_store = WC_Data_Store::load( 'order-item' );
 	if ( $meta_id = $data_store->add_metadata( $item_id, $meta_key, $meta_value, $unique ) ) {
-		$cache_key = WC_Cache_Helper::get_cache_prefix( 'orders' ) . 'item_meta_array_' . $item_id;
-		wp_cache_delete( $cache_key, 'orders' );
+		$cache_key = WC_Cache_Helper::get_cache_prefix( 'order-items' ) . 'object_meta_' . $item_id;
+		wp_cache_delete( $cache_key, 'order-items' );
 		return $meta_id;
 	}
 	return 0;
@@ -138,8 +138,8 @@ function wc_add_order_item_meta( $item_id, $meta_key, $meta_value, $unique = fal
 function wc_delete_order_item_meta( $item_id, $meta_key, $meta_value = '', $delete_all = false ) {
 	$data_store = WC_Data_Store::load( 'order-item' );
 	if ( $data_store->delete_metadata( $item_id, $meta_key, $meta_value, $delete_all ) ) {
-		$cache_key = WC_Cache_Helper::get_cache_prefix( 'orders' ) . 'item_meta_array_' . $item_id;
-		wp_cache_delete( $cache_key, 'orders' );
+		$cache_key = WC_Cache_Helper::get_cache_prefix( 'order-items' ) . 'object_meta_' . $item_id;
+		wp_cache_delete( $cache_key, 'order-items' );
 		return true;
 	}
 	return false;
diff --git a/tests/unit-tests/order-items/functions.php b/tests/unit-tests/order-items/functions.php
new file mode 100644
index 00000000000..f80ae8b7721
--- /dev/null
+++ b/tests/unit-tests/order-items/functions.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * Order Item Function Tests
+ * @package WooCommerce\Tests\Order_Items
+ * @since 2.7.0
+ */
+class WC_Tests_Order_Item_Functions extends WC_Unit_Test_Case {
+
+	/**
+	 * test_wc_order_item_meta_functions
+	 *
+	 * wc_add_order_item_meta, wc_update_order_item_meta, and
+	 * wc_delete_order_item_meta all make direct updates through
+	 * a datastore. These tests make sure cache is properly busted and
+	 * accessing those values via CRUD returns the correct value.
+	 *
+	 * @since 2.7.0
+	 */
+	function test_wc_order_item_meta_functions() {
+		$meta_value  = 'cat';
+		$meta_value2 = 'dog';
+
+		$order  = new WC_Order();
+		$item_1 = new WC_Order_Item_Product();
+		$item_1->set_props( array(
+			'product'  => WC_Helper_Product::create_simple_product(),
+			'quantity' => 4,
+		) );
+		$order->add_item( $item_1 );
+		$order->save();
+
+		$item    = current( $order->get_items() );
+		$item_id = $item->get_id();
+
+		// Test that the initial key doesn't exist.
+		$item = new WC_Order_Item_Product( $item_id );;
+		$this->assertEmpty( $item->get_meta( '_test_key' ) );
+		$this->assertEmpty( wc_get_order_item_meta( $item_id, '_test_key' ) );
+
+		// Test making sure cache is properly busted when adding meta.
+		wc_add_order_item_meta( $item_id, '_test_key', $meta_value );
+		$item      = new WC_Order_Item_Product( $item_id );
+		$item_meta = $item->get_meta( '_test_key' );
+		$this->assertEquals( $meta_value, $item_meta );
+		$this->assertEquals( $meta_value, wc_get_order_item_meta( $item_id, '_test_key' ) );
+
+		// Test making sure cache is properly busted when updating meta.
+		wc_update_order_item_meta( $item_id, '_test_key', $meta_value2 );
+		$item      = new WC_Order_Item_Product( $item_id );
+		$item_meta = $item->get_meta( '_test_key' );
+		$this->assertEquals( $meta_value2, $item_meta );
+		$this->assertEquals( $meta_value2, wc_get_order_item_meta( $item_id, '_test_key' ) );
+
+		// Test making sure cache is properly busted when deleting meta.
+		wc_delete_order_item_meta( $item_id, '_test_key' );
+		$item      = new WC_Order_Item_Product( $item_id );
+		$item_meta = $item->get_meta( '_test_key' );
+		$this->assertEmpty( $item->get_meta( '_test_key' ) );
+		$this->assertEmpty( wc_get_order_item_meta( $item_id, '_test_key' ) );
+	}
+
+}