assertProductInOrder example

$this->assertLineItemTotalPrice($cart, $product->id, 100);

        $orderId = $this->mailListener(function DMailEventListener $listener) use ($cart, $context) {
            $orderId = $this->order($cart, $context);

            $listener->assertSent('order_confirmation_mail');

            return $orderId;
        });

        $item = $this->assertProductInOrder($orderId, $product->id);

        static::assertEquals(100, $item->getUnitPrice());

        static::assertEquals(100, $item->getTotalPrice());

        if (Feature::isActive('STOCK_HANDLING')) {
            $this->assertStock($product->id, 99, 99);
        } else {
            $this->assertStock($product->id, 100, 99);
        }
    }
}