Wrong price after sellingPlanGroupUpdate mutation with pricingPolicies

[andveaupp]

Hi,

I've a product's variant that costs 3.5€ associated to one sellingPlanGroup. This sellingPlanGroup has 2 sellingPlans: one with monthly billing cycle (3.5€ per month) and one with annual prepaid billing cycle (3.5€ x 12 = 42€). If I update the sellingPlan's pricingPolicies in order to apply some discount, then the final price is wrong.

E.g. I would like to add 10€ (fixed value) "discount" to the annual plan (so from 42€ to 32€), but the new subtotal is 31.90€. You can find screenshots below. 

[LarryReid]

Thanks very much for reporting this. I've created a ticket and assigned it for resolution. Sorry for the inconvenience.

[andveaupp]

Hi @LarryReid!
Thank you for your answer. Will you write here once the ticket is resolved?

[LarryReid · Accepted solution]

It turns out that what you're observing is due to the fixed discount not be evenly divisible by the number of deliveries. In your example, when we divide the 10€ by 12 we get 0,83333... which we round up to 0,84€ per month. 0,84 X 12 is 10,08€, which is why the total price is shown as 31,92€, instead of 32€.

Note that in general Shopify does a very good job of handling round-off issues. Unfortunately, fixed amount discounts for subscriptions can't be easily handled.

Please let me know if you have further questions.