"State" is not passed to promotion action `onActivate` function

[michaelbromley]

Is your feature request related to a problem? Please describe.
Requirement: a promotion like "for every N of Product A, add free gift B"

Currently this is not possible because the value of N (which would be calculated by the PromotionCondition and passed as state to the PromotionAction) is not available in the side-effect API methods onActivate and onDeactivate. Thus there is no way to know how many free gifts to add.

Describe the solution you'd like
Add a state arg to those functions, passing in the data object from the dependent promo condition(s).

Describe alternatives you've considered
Re-implement the logic in the action to calculate the number to add, but this is bad for efficiency and maintenance.

[dlhck]

Note: This issue needs to be expanded to generally think about the current implementation of promotions. Therefore more research needed.

[mschipperheyn]

Yeah, I'm currently working around this by passing orderLineIds that pass the test on a custom ctx key. We work extensively with orderLine specific promotions bc we relate subscription to orderLines, and our promotions have "payNow" and "Future" discount option. Feel free to reach out if you're interested to know how we worked around the limitations.

Another limitations we work around is the filtering of side effect application by only doing this for "new promotions". This creates a lot of problems for us and we forcibly run ALL coupon side effects when the cart changes.