Wrong cart items total if promotion on units

[Roshyo]

Sylius version affected: 1.7 for sure, and I believe all previous as well

Description
We have a cart composed of 3 quantities of 1 product, $100 each.
If we apply a promotion of 100 split among those units, we will have

• Unit1: 100 - 34
• Unit2: 100 - 33
• Unit3: 100 - 33

Everything is good from amount perspective, but in the cart summary, we end up having something like this :

The Order total is right, but since each Beige Strappy summer dress costs $71.40, the items total is wrong.
In fact, those Beige Strappy summer dress costs $71.40, $71.39 and $71.39

Steps to reproduce
Apply a different promotion to first unit of an order item with multiple units and go to cart page.

Possible Solution
This has something to do with the way item total and itemsTotal are calculated.

[stale]

This issue has been automatically marked as stale because it has not had any recent activity. It will be closed in a week if no further activity occurs. Thank you for your contributions.

[Roshyo]

Do not stale please

[laurentdabbb]

Hi,

Please consider this as a bug.

Bug is on the getSubtotal() method on OrderItem.
This method return $this->getDiscountedUnitPrice() * $this->quantity;

The problem is that getDiscountedUnitPrice() only retrieve discounted price from the first orderItem unit.

I encountered same issue with a new custom type of promotion "percentage discount on the Nth cheapest article".
This promotion allow to purpose promotion operations like "2+ 1 free".
With this promotion, I apply a 100% discount adjustment on cheapest unit. If this unit is the first unit of an orderItem, getSubtotal method return 0 whereas other units on this orderItem are not free...

Sylius version affected
I'm on 1.10.6

Possible solution
Do not use getDiscountedUnitPrice() in the getSubtotal() calculation

[NoResponseMate]

Hi @Roshyo

It seems the bug has been fixed in 1.11 via #14090
Let me know if that's not the case, but for now, I'm closing this issue.

Cheers 🍻