Previously, the order serializer would pull in all promotions regardless
of whether they were eligible or not and display the promotion_code.
This also causes breakage with order promotions that apply to all orders,
as those promotions do not have promotion_codes.
This only displays eligible promotions in the serializer, and if no
promotion code exists, will set the promotion code to "all orders".
Previously, the order serializer would pull in all promotions regardless of whether they were eligible or not and display the promotion_code. This also causes breakage with order promotions that apply to all orders, as those promotions do not have promotion_codes.
This only displays eligible promotions in the serializer, and if no promotion code exists, will set the promotion code to "all orders".