When I apply a promotion with two actions, the usage count goes up by two

[yedhukrishnan]

I created a promotion with two actions:

1. A whole order adjustment with a flat percentage of 100%
2. Free shipping

When I successfully apply this coupon and checkout, the current usage goes up by 2.

Context

We use the credits_count method to show the current usage. The credits method is defined as follows:

def credits
  Adjustment.eligible.promotion.where(source_id: actions.map(&:id))
end

In the scenario above, the order has two adjustments: one for shipping and one for the order itself.

Is this an expected behavior? When I set the usage limit to 5, I expect the promotion to be applied to 5 orders. But now, I must set it to 5 times the number of adjustments to be applied to the order.

Expected Behavior

I expect the usage count to increase by one when I apply the above coupon to the order.

Actual Behavior

The usage count went up by two since the order had two adjustments.

Your Environment

• Version used: 4.4.0

Please let me know if I need to do anything differently here or if my understanding of how the credits work needs to be corrected. I was not able to find documentation on it anywhere.

[jonathankroll13]

This same issue happens if you have a line item-based promotion (since spree doesn't do whole order adjustments for tax calculations. See #10907) and you have multiple items in the order. The number of usages ends up being the amount of line items there are. If you have a usage limit set to 1, only one line item gets the promotion. Not sure if the root cause is the same here, but it seems related.