[13, 14, 15] sale_coupon - erratic behaviors when applying promo to SO

[francesco-ooops]

Impacted versions: 13, 14, 15

Steps to reproduce:
Take as an example demo data coupon "Buy 3 large cabinets, get one for free"

Field "Quantity" (description reads: "Minimum required product qty to get the reward") is set to 3

BEHAVIOR 1 (video)
In SO line, I select product "large cabinet", qty = 3 > click on promotion

Current behavior:
Promotion is not applied ?
Change qty to 4 on SOL > click on promotion again > promotion is applied

Expected behavior:

Promotion should be applied if value for "Quantity" on SO line >= the value in field "Quantity" in promotion

BEHAVIOR 2 (video)

Use same promotion "Buy 3 large cabinets, get one for free" but change reward to "discount", 10%, on order
In SO line, I set product "large cabinet", set qty = 3 > click on promotion

Current behavior:

Promotion is applied correctly with SOL product qty = 3
(product code is still "FREELARGECABINET" tho?)

Expected behavior:

Yes, this is expected behavior as min qty in promotion = qty in SO line
but internal reference could be fixed as it feels buggy

BEHAVIOR 3 (video)

Use same promotion "Buy 3 large cabinets, get one for free" but change reward to "free product", where free product = "whiteboard pen"
In SO line, I set product "large cabinet", set qty = 3 > click on promotion

Current behavior:

Promotion is not applied at all
(internal code for reward line product is still "FREELARGECABINET")

[francesco-ooops]

@pedrobaeza @chienandalu just FYI as we're working on this stuff in OCA

[chienandalu]

Well, @francesco-ooops it isn't very intuitive indeed but that's how it works at least until 16.0 where all the promos stuff it's being revamped.

The rule of thumb is:

• When you want to enjoy a free product you have to add it manually to the cart.

Keep in mind that the promo conditions and the promo rewards are evaluated separately. They're even different models glued together into coupon.program

Not that we like it (we made some modules that override that behavior) but that's how it is by now.

Take a look into master, anyway. Maybe there's margin there to add some improvements :)