Fixes for calculations with refunds involved

Konamiman · Konamiman · commit 26fcbe925809 · 2025-10-07T17:04:02.000+02:00
diff --git a/plugins/woocommerce/includes/class-wc-order-item-product.php b/plugins/woocommerce/includes/class-wc-order-item-product.php
@@ -562,15 +562,19 @@ public function has_cogs(): bool {
 	 * @return float|null The calculated value, null if the product associated to the line item no longer exists.
 	 */
 	public function calculate_cogs_value_core(): ?float {
-		// If this item has been loaded from the database and has a saved COGS value, preserve it.
+		// Refund items should always recalculate based on their (negative) quantity.
+		// Preserving would give incorrect values since they're cloned from original items.
+		$is_refund_item = $this->get_quantity() < 0;
+
+		// If this is a regular item (not refund) that has been loaded from the database and has a saved COGS value, preserve it.
 		// COGS values should be "snapshotted" at order creation time, not recalculated later.
 		// This prevents historical orders from having their costs changed when product prices are updated.
 		// Note: cogs_value will be null if the item was loaded but had no _cogs_value metadata.
-		if ( $this->get_id() > 0 && $this->get_object_read() && isset( $this->data['cogs_value'] ) && ! is_null( $this->data['cogs_value'] ) ) {
+		if ( ! $is_refund_item && $this->get_id() > 0 && $this->get_object_read() && isset( $this->data['cogs_value'] ) && ! is_null( $this->data['cogs_value'] ) ) {
 			return $this->get_cogs_value( 'edit' );
 		}
 
-		// Otherwise, calculate from the product.
+		// For new items, refund items, or items without saved COGS, calculate from the product.
 		$product = $this->get_product();
 		if ( ! $product ) {
 			return null;
diff --git a/plugins/woocommerce/tests/php/includes/data-stores/class-wc-order-data-store-cpt-test.php b/plugins/woocommerce/tests/php/includes/data-stores/class-wc-order-data-store-cpt-test.php
@@ -1200,4 +1200,61 @@ public function test_items_without_saved_cogs_calculate_from_product() {
 		$this->assertEquals( $expected_cogs, $reloaded_item->get_cogs_value(), 'Item without saved COGS should calculate from product' );
 		$this->assertEquals( $expected_cogs, $reloaded_order->get_cogs_total_value(), 'Order total should reflect calculated item COGS' );
 	}
+
+	/**
+	 * @testDox Refund items always recalculate COGS based on their negative quantity.
+	 */
+	public function test_refund_items_recalculate_cogs() {
+		$this->enable_cogs_feature();
+
+		$product_cost         = 20.00;
+		$product_qty          = 10;
+		$refund_qty           = 3;
+		$expected_order_cogs  = $product_cost * $product_qty;
+		$expected_refund_cogs = -( $product_cost * $refund_qty );
+
+		// Create a product with COGS and price.
+		$product = WC_Helper_Product::create_simple_product();
+		$product->set_regular_price( $product_cost );
+		$product->set_cogs_value( $product_cost );
+		$product->save();
+
+		// Create an order with COGS.
+		$order = new WC_Order();
+		$order->add_product( $product, $product_qty );
+		$order->calculate_totals();
+		$order->save();
+
+		$this->assertEquals( $expected_order_cogs, $order->get_cogs_total_value() );
+
+		// Get the order item.
+		$order_items = array_values( $order->get_items( 'line_item' ) );
+		$order_item  = $order_items[0];
+
+		// Create a refund.
+		$refund = wc_create_refund(
+			array(
+				'order_id'   => $order->get_id(),
+				'amount'     => $product_cost * $refund_qty,
+				'reason'     => 'testing',
+				'line_items' => array(
+					$order_item->get_id() => array(
+						'qty'          => $refund_qty,
+						'refund_total' => $product_cost * $refund_qty,
+					),
+				),
+			)
+		);
+
+		$this->assertNotInstanceOf( 'WP_Error', $refund, 'Refund creation should not return an error' );
+		$refund->save();
+
+		// Verify the refund has the correct COGS (negative value).
+		$this->assertEquals( $expected_refund_cogs, $refund->get_cogs_total_value(), 'Refund should have negative COGS' );
+
+		// Recalculate order totals and verify COGS is adjusted for the refund.
+		$order->calculate_totals();
+		$expected_final_cogs = $expected_order_cogs + $expected_refund_cogs;
+		$this->assertEquals( $expected_final_cogs, $order->get_cogs_total_value(), 'Order COGS should be reduced by refund amount' );
+	}
 }
