Merge pull request #6424 from mamhoff/validate-order-promotion-uniqueness

OrderPromotions: Validate promotion uniqueness per order

Author: mamhoff

promotions/app/models/solidus_promotions/order_promotion.rb

@@ -11,6 +11,7 @@ class OrderPromotion < Spree::Base
     belongs_to :promotion_code, class_name: "SolidusPromotions::PromotionCode", optional: true
 
     validates :promotion_code, presence: true, if: :require_promotion_code?
+    validates :promotion_id, uniqueness: { scope: :order_id }
 
     self.allowed_ransackable_associations = %w[promotion_code]
 

promotions/spec/models/solidus_promotions/order_promotion_spec.rb

@@ -10,6 +10,8 @@
   let(:promotion) { build(:solidus_promotion) }
   let(:order_promotion) { build(:solidus_order_promotion, promotion: promotion) }
 
+  it { is_expected.to validate_uniqueness_of(:promotion_id).scoped_to(:order_id) }
+
   describe "promotion code presence error" do
     subject do
       order_promotion.valid?