And deletion sync related tests for OrdersTableDataStore.

Also:

- toggle_cot renamed to toggle_cot_feature_and_usage includes
  HPOSToggleTrais for clarity.
- DataSynchronizerTests and OrdersTableDataStoreTests now inherit
  from a common HposTestCase class.

plugins/woocommerce/tests/legacy/unit-tests/rest-api/Helpers/OrderHelper.php

@@ -331,5 +331,4 @@ class OrderHelper {
 
 		return $order;
 	}
-
 }

plugins/woocommerce/tests/php/helpers/HPOSToggleTrait.php

@@ -28,14 +28,14 @@ trait HPOSToggleTrait {
 		OrderHelper::delete_order_custom_tables();
 		OrderHelper::create_order_custom_table_if_not_exist();
 
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 	}
 
 	/**
 	 * Call in teardown to disable COT/HPOS.
 	 */
 	public function clean_up_cot_setup(): void {
-		$this->toggle_cot( false );
+		$this->toggle_cot_feature_and_usage( false );
 
 		// Add back removed filter.
 		add_filter( 'query', array( $this, '_create_temporary_tables' ) );
@@ -43,12 +43,12 @@ trait HPOSToggleTrait {
 	}
 
 	/**
-	 * Enables or disables the custom orders table across WP temporarily.
+	 * Enables or disables the custom orders table feature, and sets the orders table as authoritative, across WP temporarily.
 	 *
 	 * @param boolean $enabled TRUE to enable COT or FALSE to disable.
 	 * @return void
 	 */
-	private function toggle_cot( bool $enabled ): void {
+	private function toggle_cot_feature_and_usage( bool $enabled ): void {
 		$features_controller = wc_get_container()->get( Featurescontroller::class );
 		$features_controller->change_feature_enable( 'custom_order_tables', $enabled );
 
@@ -59,6 +59,14 @@ trait HPOSToggleTrait {
 		assert( is_a( $wc_data_store->get_current_class_name(), OrdersTableDataStore::class, true ) === $enabled );
 	}
 
+	/**
+	 * Set the orders table or the posts table as the authoritative table to store orders.
+	 * @param bool $cot_authoritative True to set the orders table as authoritative, false to set the posts table as authoritative.
+	 */
+	protected function toggle_cot_authoritative( bool $cot_authoritative ) {
+		update_option( CustomOrdersTableController::CUSTOM_ORDERS_TABLE_USAGE_ENABLED_OPTION, wc_bool_to_string( $cot_authoritative ) );
+	}
+
 	/**
 	 * Helper function to enable COT <> Posts sync.
 	 */

plugins/woocommerce/tests/php/includes/wc-user-functions-test.php

@@ -14,7 +14,7 @@ class WC_User_Functions_Tests extends WC_Unit_Test_Case {
 	public function setUp(): void {
 		parent::setUp();
 		$this->setup_cot();
-		$this->toggle_cot( false );
+		$this->toggle_cot_feature_and_usage( false );
 	}
 
 	/**
@@ -29,7 +29,7 @@ class WC_User_Functions_Tests extends WC_Unit_Test_Case {
 	 * Test wc_get_customer_order_count. Borrowed from `WC_Tests_Customer_Functions` class for COT.
 	 */
 	public function test_hpos_wc_customer_bought_product() {
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$customer_id_1 = wc_create_new_customer( 'test@example.com', 'testuser', 'testpassword' );
 		$customer_id_2 = wc_create_new_customer( 'test2@example.com', 'testuser2', 'testpassword2' );
 		$product_1     = new WC_Product_Simple();

plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/DataSynchronizerTests.php

@@ -5,13 +5,17 @@ use Automattic\WooCommerce\Internal\DataStores\Orders\DataSynchronizer;
 use Automattic\WooCommerce\Internal\DataStores\Orders\OrdersTableDataStore;
 use Automattic\WooCommerce\Internal\Features\FeaturesController;
 use Automattic\WooCommerce\RestApi\UnitTests\Helpers\OrderHelper;
+use Automattic\WooCommerce\RestApi\UnitTests\HPOSToggleTrait;
 use DMS\PHPUnitExtensions\ArraySubset\ArraySubsetAsserts;
 
+require_once __DIR__ . '/../../../../helpers/HPOSToggleTrait.php';
+
 /**
  * Tests for DataSynchronizer class.
  */
-class DataSynchronizerTests extends WC_Unit_Test_Case {
+class DataSynchronizerTests extends HposTestCase {
 	use ArraySubsetAsserts;
+	use HPOSToggleTrait;
 
 	/**
 	 * @var DataSynchronizer
@@ -231,23 +235,23 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 	 * @param bool $manual_sync True to trigger synchronization manually, false if automatic synchronization is enabled.
 	 */
 	public function test_synced_order_deletion_with_sync_disabled_and_posts_authoritative_generates_proper_deletion_record_if_cot_record_exists( bool $manual_sync ) {
-		$this->set_posts_authoritative();
+		$this->toggle_cot_authoritative( false );
 
 		if ( $manual_sync ) {
-			$this->disable_data_sync();
+			$this->disable_cot_sync();
 			$order = OrderHelper::create_order();
-			$this->do_sync();
+			$this->do_cot_sync();
 		} else {
-			$this->enable_data_sync();
+			$this->enable_cot_sync();
 			$order = OrderHelper::create_order();
 		}
 
-		$this->disable_data_sync();
+		$this->disable_cot_sync();
 		$order_id = $order->get_id();
 		$order->delete( true );
 
 		$this->assert_deletion_record_existence( $order_id, false );
-		$this->assert_order_record_existence( $order_id, true );
+		$this->assert_order_record_existence( $order_id, true, true );
 	}
 
 	/**
@@ -256,8 +260,8 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 	 * @return void
 	 */
 	public function test_synced_order_deletion_with_sync_disabled_and_posts_authoritative_not_generating_deletion_record_if_cot_record_not_exists() {
-		$this->set_posts_authoritative();
+		$this->toggle_cot_authoritative( false );
-		$this->disable_data_sync();
+		$this->disable_cot_sync();
 		$order = OrderHelper::create_order();
 
 		$order_id = $order->get_id();
@@ -282,19 +286,15 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 
 		$meta_table_name = OrdersTableDataStore::get_meta_table_name();
 
-		if ( $cot_is_authoritative ) {
+		$this->toggle_cot_authoritative( $cot_is_authoritative );
-			$this->set_cot_authoritative();
-		} else {
-			$this->set_posts_authoritative();
-		}
 
-		$this->enable_data_sync();
+		$this->enable_cot_sync();
 		$order_1 = OrderHelper::create_order();
 		$order_2 = OrderHelper::create_order();
 		$order_3 = OrderHelper::create_order();
 		$order_4 = OrderHelper::create_order();
 
-		$this->disable_data_sync();
+		$this->disable_cot_sync();
 		if ( $new_records_exist ) {
 			$order_5 = OrderHelper::create_order();
 		}
@@ -323,19 +323,15 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 	 * @param bool $cot_is_authoritative True to test with the orders table as authoritative, false to test with the posts table as authoritative.
 	 */
 	public function test_process_batch_processes_modified_and_deleted_orders( bool $cot_is_authoritative ) {
-		if ( $cot_is_authoritative ) {
+		$this->toggle_cot_authoritative( $cot_is_authoritative );
-			$this->set_cot_authoritative();
+		$this->enable_cot_sync();
-		} else {
-			$this->set_posts_authoritative();
-		}
 
-		$this->enable_data_sync();
 		$order_1 = OrderHelper::create_order();
 		$order_2 = OrderHelper::create_order();
 		$order_3 = OrderHelper::create_order();
 		$order_4 = OrderHelper::create_order();
 
-		$this->disable_data_sync();
+		$this->disable_cot_sync();
 
 		$order_1->set_date_modified( '2100-01-01 00:00:00' );
 		$order_1->save();
@@ -387,22 +383,19 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 		$this->register_legacy_proxy_function_mocks(
 			array(
 				'wc_get_logger' => function() use ( $logger ) {
-					return $logger;},
+					return $logger;
+				},
 			)
 		);
 		$this->sut = wc_get_container()->get( DataSynchronizer::class );
 
-		if ( $cot_is_authoritative ) {
+		$this->toggle_cot_authoritative( $cot_is_authoritative );
-			$this->set_cot_authoritative();
+		$this->enable_cot_sync();
-		} else {
-			$this->set_posts_authoritative();
-		}
 
-		$this->enable_data_sync();
 		$order_1 = OrderHelper::create_order();
 		$order_2 = OrderHelper::create_order();
 
-		$this->disable_data_sync();
+		$this->disable_cot_sync();
 
 		$order_1_id = $order_1->get_id();
 		$order_1->delete( true );
@@ -419,104 +412,4 @@ class DataSynchronizerTests extends WC_Unit_Test_Case {
 
 		$this->assertEquals( array( "Order {$order_1_id} doesn't exist in the backup table, thus it can't be deleted" ), $logger->warnings );
 	}
-
-	/**
-	 * Assert that a given order record exists or doesn't exist.
-	 *
-	 * @param int  $order_id The order id to check.
-	 * @param bool $in_cot True to assert that the order exists or not in the orders table, false to check in the posts table.
-	 * @param bool $exists True to assert that the order exists, false to check that the order doesn't exist.
-	 * @return void
-	 */
-	private function assert_order_record_existence( $order_id, $in_cot, $exists = true ) {
-		global $wpdb;
-
-		$table_name = $in_cot ? OrdersTableDataStore::get_orders_table_name() : $wpdb->posts;
-
-		//phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
-		$exists = $wpdb->get_var(
-			$wpdb->prepare(
-				"SELECT EXISTS (SELECT id FROM {$table_name} WHERE id = %d)",
-				$order_id
-			)
-		);
-		//phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
-
-		if ( $exists ) {
-			$this->assertTrue( (bool) $exists, "No order found with id $order_id in table $table_name" );
-		} else {
-			$this->assertFalse( (bool) $exists, "Unexpected order found with id $order_id in table $table_name" );
-		}
-	}
-
-	/**
-	 * Assert that an order deletion record exists or doesn't exist in the orders meta table.
-	 *
-	 * @param int  $order_id The order id to check.
-	 * @param bool $deleted_from_cot True to assert that the record corresponds to an order deleted from the orders table, or from the posts table otherwise.
-	 * @param bool $exists True to assert that the record exists, false to assert that the record doesn't exist.
-	 * @return void
-	 */
-	private function assert_deletion_record_existence( $order_id, $deleted_from_cot, $exists = true ) {
-		global $wpdb;
-
-		$meta_table_name = OrdersTableDataStore::get_meta_table_name();
-		//phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
-		$record = $wpdb->get_row(
-			$wpdb->prepare(
-				"SELECT meta_value FROM $meta_table_name WHERE order_id = %d AND meta_key = %s",
-				$order_id,
-				'deleted_from'
-			),
-			ARRAY_A
-		);
-		//phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
-
-		if ( $exists ) {
-			$this->assertNotNull( $record, "No deletion record found for order id {$order_id}, value: {$record['meta_value']}" );
-		} else {
-			$this->assertNull( $record, "Unexpected deletion record found for order id {$order_id}" );
-			return;
-		}
-
-		$deleted_from = $deleted_from_cot ? OrdersTableDataStore::get_orders_table_name() : $wpdb->posts;
-
-		$this->assertEquals( $deleted_from, $record['meta_value'], "Deletion record for order {$order_id} has a value of {$record['meta_value']}, expected {$deleted_from}" );
-	}
-
-	/**
-	 * Synchronize all the pending unsynchronized orders.
-	 */
-	private function do_sync() {
-		$batch = $this->sut->get_next_batch_to_process( 100 );
-		$this->sut->process_batch( $batch );
-	}
-
-	/**
-	 * Set the orders table as authoritative.
-	 */
-	private function set_cot_authoritative() {
-		update_option( CustomOrdersTableController::CUSTOM_ORDERS_TABLE_USAGE_ENABLED_OPTION, 'yes' );
-	}
-
-	/**
-	 * Set the posts table as authoritative.
-	 */
-	private function set_posts_authoritative() {
-		update_option( CustomOrdersTableController::CUSTOM_ORDERS_TABLE_USAGE_ENABLED_OPTION, 'no' );
-	}
-
-	/**
-	 * Enable the orders synchronization.
-	 */
-	private function enable_data_sync() {
-		update_option( $this->sut::ORDERS_DATA_SYNC_ENABLED_OPTION, 'yes' );
-	}
-
-	/**
-	 * Disable the orders synchronization.
-	 */
-	private function disable_data_sync() {
-		update_option( $this->sut::ORDERS_DATA_SYNC_ENABLED_OPTION, 'no' );
-	}
 }

plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/HposTestCase.php

@@ -0,0 +1,87 @@
+<?php
+
+use Automattic\WooCommerce\Internal\DataStores\Orders\DataSynchronizer;
+use Automattic\WooCommerce\Internal\DataStores\Orders\OrdersTableDataStore;
+
+/**
+ * Base class for HPOS related unit test suites.
+ */
+class HposTestCase extends WC_Unit_Test_Case {
+
+	/**
+	 * Assert that a given order record exists or doesn't exist.
+	 *
+	 * @param int    $order_id The order id to check.
+	 * @param bool   $in_cot True to assert that the order exists or not in the orders table, false to check in the posts table.
+	 * @param bool   $must_exist True to assert that the order exists, false to check that the order doesn't exist.
+	 * @param string $order_type Expected order type, null to accept any type that starts with "shop_order".
+	 * @return void
+	 */
+	protected function assert_order_record_existence( $order_id, $in_cot, $must_exist, $order_type = null ) {
+		global $wpdb;
+
+		$table_name = $in_cot ? OrdersTableDataStore::get_orders_table_name() : $wpdb->posts;
+		$order_type = $order_type ?? 'shop_order%';
+		$sql        = $in_cot ?
+			"SELECT EXISTS (SELECT id FROM $table_name WHERE id = %d)" :
+			"SELECT EXISTS (SELECT ID FROM $table_name WHERE ID = %d AND post_type LIKE %s)";
+
+		//phpcs:disable WordPress.DB.PreparedSQL.NotPrepared
+		$exists = $wpdb->get_var(
+			$in_cot ?
+				$wpdb->prepare( $sql, $order_id ) :
+				$wpdb->prepare( $sql, $order_id, $order_type )
+		);
+		//phpcs:enable WordPress.DB.PreparedSQL.NotPrepared
+
+		if ( $must_exist ) {
+			$this->assertTrue( (bool) $exists, "No order found with id $order_id in table $table_name" );
+		} else {
+			$this->assertFalse( (bool) $exists, "Unexpected order found with id $order_id in table $table_name" );
+		}
+	}
+
+	/**
+	 * Assert that an order deletion record exists or doesn't exist in the orders meta table.
+	 *
+	 * @param int  $order_id The order id to check.
+	 * @param bool $deleted_from_cot True to assert that the record corresponds to an order deleted from the orders table, or from the posts table otherwise.
+	 * @param bool $must_exist True to assert that the record exists, false to assert that the record doesn't exist.
+	 * @return void
+	 */
+	protected function assert_deletion_record_existence( $order_id, $deleted_from_cot, $must_exist = true ) {
+		global $wpdb;
+
+		$meta_table_name = OrdersTableDataStore::get_meta_table_name();
+		//phpcs:disable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+		$record = $wpdb->get_row(
+			$wpdb->prepare(
+				"SELECT meta_value FROM $meta_table_name WHERE order_id = %d AND meta_key = %s",
+				$order_id,
+				'deleted_from'
+			),
+			ARRAY_A
+		);
+		//phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+
+		if ( $must_exist ) {
+			$this->assertNotNull( $record, "No deletion record found for order id {$order_id}" );
+		} else {
+			$this->assertNull( $record, "Unexpected deletion record found for order id {$order_id}" );
+			return;
+		}
+
+		$deleted_from = $deleted_from_cot ? OrdersTableDataStore::get_orders_table_name() : $wpdb->posts;
+
+		$this->assertEquals( $deleted_from, $record['meta_value'], "Deletion record for order {$order_id} has a value of {$record['meta_value']}, expected {$deleted_from}" );
+	}
+
+	/**
+	 * Synchronize all the pending unsynchronized orders.
+	 */
+	protected function do_cot_sync() {
+		$sync  = wc_get_container()->get( DataSynchronizer::class );
+		$batch = $sync->get_next_batch_to_process( 100 );
+		$sync->process_batch( $batch );
+	}
+}

plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreRestOrdersControllerTests.php

@@ -29,14 +29,14 @@ class OrdersTableDataStoreRestOrdersControllerTests extends \WC_REST_Orders_Cont
 		OrderHelper::delete_order_custom_tables();
 		OrderHelper::create_order_custom_table_if_not_exist();
 
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 	}
 
 	/**
 	 * Destroys system under test.
 	 */
 	public function tearDown(): void {
-		$this->toggle_cot( false );
+		$this->toggle_cot_feature_and_usage( false );
 
 		// Add back removed filter.
 		add_filter( 'query', array( $this, '_create_temporary_tables' ) );
@@ -51,7 +51,7 @@ class OrdersTableDataStoreRestOrdersControllerTests extends \WC_REST_Orders_Cont
 	public function test_orders_cpt() {
 		wp_set_current_user( $this->user );
 
-		$this->toggle_cot( false );
+		$this->toggle_cot_feature_and_usage( false );
 		$post_order_id = OrderHelper::create_complex_wp_post_order();
 		( wc_get_container()->get( PostsToOrdersMigrationController::class ) )->migrate_orders( array( $post_order_id ) );
 
@@ -62,7 +62,7 @@ class OrdersTableDataStoreRestOrdersControllerTests extends \WC_REST_Orders_Cont
 		$response_cpt_data = $response_cpt->get_data();
 
 		// Re-enable COT.
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 
 		$response_cot = $this->server->dispatch( $request );
 		$this->assertEquals( 200, $response_cot->get_status() );
@@ -91,7 +91,7 @@ class OrdersTableDataStoreRestOrdersControllerTests extends \WC_REST_Orders_Cont
 	 * @param boolean $enabled TRUE to enable COT or FALSE to disable.
 	 * @return void
 	 */
-	private function toggle_cot( bool $enabled ): void {
+	private function toggle_cot_feature_and_usage( bool $enabled ): void {
 		$features_controller = wc_get_container()->get( Featurescontroller::class );
 		$features_controller->change_feature_enable( 'custom_order_tables', true );
 

plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreTests.php

@@ -15,7 +15,7 @@ require_once __DIR__ . '/../../../../helpers/HPOSToggleTrait.php';
  *
  * Test for OrdersTableDataStore class.
  */
-class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
+class OrdersTableDataStoreTests extends HposTestCase {
 	use HPOSToggleTrait;
 
 	/**
@@ -50,7 +50,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 		parent::setUp();
 		// Remove the Test Suite’s use of temporary tables https://wordpress.stackexchange.com/a/220308.
 		$this->setup_cot();
-		$this->toggle_cot( false );
+		$this->toggle_cot_feature_and_usage( false );
 		$container = wc_get_container();
 		$container->reset_all_resolved();
 		$this->sut            = $container->get( OrdersTableDataStore::class );
@@ -731,7 +731,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 	 * @testDox Tests queries involving 'orderby' and meta queries.
 	 */
 	public function test_cot_query_meta_orderby() {
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 
 		$order1 = new \WC_Order();
 		$order1->add_meta_data( 'color', 'red' );
@@ -1988,7 +1988,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 	 * @testDox Test that multiple calls to read don't try to sync again.
 	 */
 	public function test_read_multiple_dont_sync_again_for_same_order() {
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$this->enable_cot_sync();
 		$order = $this->create_complex_cot_order();
 
@@ -2018,7 +2018,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 			)
 		);
 
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$order = new WC_Order();
 		$order->save();
 
@@ -2045,7 +2045,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 			)
 		);
 
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$order = new WC_Order();
 		$order->save();
 
@@ -2064,7 +2064,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 	 * @testDox Make sure get_order return false when checking an order of different order types without warning.
 	 */
 	public function test_get_order_with_id_for_different_type() {
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$this->disable_cot_sync();
 		$product = new \WC_Product();
 		$product->save();
@@ -2093,7 +2093,7 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 	 */
 	public function test_address_index_saved_on_update() {
 		global $wpdb;
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$this->disable_cot_sync();
 		$order = new WC_Order();
 		$order->set_billing_address_1( '123 Main St' );
@@ -2115,4 +2115,185 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 
 		$this->assertEquals( 1, $result );
 	}
+
+	/**
+	 * @testdox When sync is enabled and an order is deleted, records in both the authoritative and the backup tables are deleted, and no deletion records are created.
+	 *
+	 * @testWith [true]
+	 *           [false]
+	 *
+	 * @param bool $cot_is_authoritative True to test with the orders table as authoritative, false to test with the posts table as authoritative.
+	 */
+	public function test_order_deletion_with_sync_enabled( bool $cot_is_authoritative ) {
+		$this->allow_current_user_to_delete_posts();
+		$this->toggle_cot_feature_and_usage( true );
+		$this->toggle_cot_authoritative( $cot_is_authoritative );
+		$this->enable_cot_sync();
+
+		list($order, $refund) = $this->create_order_with_refund();
+
+		$order_id  = $order->get_id();
+		$refund_id = $refund->get_id();
+
+		$order->delete( true );
+
+		$this->assert_no_order_records_or_deletion_records_exist( $order_id, $refund_id, $cot_is_authoritative );
+	}
+
+	/**
+	 * @testdox Deletion records are created when an order is deleted with sync disabled, then when sync is enabled all order and deletion records are deleted.
+	 *
+	 * @testWith [true]
+	 *           [false]
+	 *
+	 * @param bool $cot_is_authoritative True to test with the orders table as authoritative, false to test with the posts table as authoritative.
+	 */
+	public function test_order_deletion_with_sync_disabled( bool $cot_is_authoritative ) {
+		$this->allow_current_user_to_delete_posts();
+		$this->toggle_cot_feature_and_usage( true );
+		$this->toggle_cot_authoritative( $cot_is_authoritative );
+		$this->enable_cot_sync();
+
+		list($order, $refund) = $this->create_order_with_refund();
+		$order_id             = $order->get_id();
+		$refund_id            = $refund->get_id();
+
+		$this->disable_cot_sync();
+		$order->delete( true );
+
+		$this->assert_order_record_existence( $order_id, true, ! $cot_is_authoritative );
+		$this->assert_order_record_existence( $order_id, false, $cot_is_authoritative );
+		$this->assert_order_record_existence( $refund_id, true, ! $cot_is_authoritative );
+		$this->assert_order_record_existence( $refund_id, false, $cot_is_authoritative );
+
+		$this->assert_deletion_record_existence( $order_id, $cot_is_authoritative, true );
+		$this->assert_deletion_record_existence( $refund_id, $cot_is_authoritative, true );
+
+		$this->do_cot_sync();
+
+		$this->assert_no_order_records_or_deletion_records_exist( $order_id, $refund_id, $cot_is_authoritative );
+	}
+
+	/**
+	 * @testdox When the orders table is authoritative, sync is disabled and an order is deleted, existing placeholder records are deleted from the posts table.
+	 */
+	public function test_order_deletion_with_sync_disabled_when_placeholders_are_created() {
+		$this->allow_current_user_to_delete_posts();
+		$this->toggle_cot_feature_and_usage( true );
+		$this->toggle_cot_authoritative( true );
+		$this->disable_cot_sync();
+
+		list($order, $refund) = $this->create_order_with_refund();
+		$order_id             = $order->get_id();
+		$refund_id            = $refund->get_id();
+
+		$this->assert_order_record_existence( $order_id, true, true );
+		$this->assert_order_record_existence( $order_id, false, true, 'shop_order_placehold' );
+		$this->assert_order_record_existence( $refund_id, true, true );
+		$this->assert_order_record_existence( $refund_id, false, true, 'shop_order_placehold' );
+
+		$order->delete( true );
+
+		$this->assert_no_order_records_or_deletion_records_exist( $order_id, $refund_id, false );
+	}
+
+	/**
+	 * @testdox When deleting an order whose associated post type is hierarchical, child orders aren't deleted and get the parent id of their parent order.
+	 */
+	public function test_order_deletion_when_post_type_is_hierarchical_results_in_child_order_upshifting() {
+		$this->reset_container_resolutions();
+		$this->reset_legacy_proxy_mocks();
+		$this->register_legacy_proxy_function_mocks(
+			array(
+				'is_post_type_hierarchical' => function( $post_type ) {
+					return 'shop_order' === $post_type ? true : is_post_type_hierarchical( $post_type );
+				},
+			)
+		);
+		$this->sut = wc_get_container()->get( OrdersTableDataStore::class );
+
+		$this->allow_current_user_to_delete_posts();
+		$this->toggle_cot_feature_and_usage( true );
+		$this->toggle_cot_authoritative( true );
+		$this->disable_cot_sync();
+
+		list($order, $refund) = $this->create_order_with_refund();
+		$order_id             = $order->get_id();
+		$refund_id            = $refund->get_id();
+
+		$this->switch_data_store( $order, $this->sut );
+
+		$order2    = OrderHelper::create_order();
+		$order2_id = $order2->get_id();
+		$order->set_parent_id( $order2_id );
+		$order->save();
+
+		$order->delete( true );
+
+		$this->assert_order_record_existence( $order_id, true, false );
+		$this->assert_order_record_existence( $refund_id, true, true );
+
+		$refund = wc_get_order( $refund_id );
+		$this->assertEquals( $order2_id, $refund->get_parent_id() );
+	}
+
+	/**
+	 * Mock the current user capabilities so that it's allowed to delete posts.
+	 *
+	 * @return void
+	 */
+	private function allow_current_user_to_delete_posts() {
+		$this->register_legacy_proxy_function_mocks(
+			array(
+				'current_user_can' => function( $capability ) {
+					return 'delete_posts' === $capability ? true : current_user_can( $capability );
+				},
+			)
+		);
+	}
+
+	/**
+	 * Assert than no records exist whatsoever, and no deletion records either, for a given order and for its refund.
+	 *
+	 * @param int  $order_id The order id to test.
+	 * @param int  $refund_id The refund id to test.
+	 * @param bool $cot_is_authoritative True if the deletion record existence is to be checked for the orders table, false for the posts table.
+	 * @return void
+	 */
+	private function assert_no_order_records_or_deletion_records_exist( $order_id, $refund_id, $cot_is_authoritative ) {
+		$this->assert_order_record_existence( $order_id, true, false );
+		$this->assert_order_record_existence( $order_id, false, false );
+		$this->assert_order_record_existence( $refund_id, true, false );
+		$this->assert_order_record_existence( $refund_id, false, false );
+
+		$this->assert_deletion_record_existence( $order_id, $cot_is_authoritative, false );
+		$this->assert_deletion_record_existence( $refund_id, $cot_is_authoritative, false );
+	}
+
+	/**
+	 * Create an order and a refund.
+	 *
+	 * @return array An array containing the order as the first element and the refund as the second element.
+	 */
+	private function create_order_with_refund() {
+		$order = OrderHelper::create_order();
+
+		$item   = current( $order->get_items() )->get_data();
+		$refund = wc_create_refund(
+			array(
+				'order_id'   => $order->get_id(),
+				'line_items' => array(
+					$item['id'] => array(
+						'id'           => $item['id'],
+						'qty'          => $item['quantity'],
+						'refund_total' => $item['total'],
+						'refund_tax'   => $item['total_tax'],
+					),
+				),
+			)
+		);
+		$refund->save();
+
+		return array( $order, $refund );
+	}
 }

plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableRefundDataStoreTests.php

@@ -79,7 +79,7 @@ class OrdersTableRefundDataStoreTests extends WC_Unit_Test_Case {
 	 */
 	public function test_refunds_backfill() {
 		$this->enable_cot_sync();
-		$this->toggle_cot( true );
+		$this->toggle_cot_feature_and_usage( true );
 		$order  = OrderHelper::create_complex_data_store_order( $this->order_data_store );
 		$refund = wc_create_refund(
 			array(