DiscountedAmount: Exclude discounts marked for destruction

If we mark any discounts for destruction, they should not be part of the
total.

Author: mamhoff

promotions/app/models/concerns/solidus_promotions/adjustment_discounts.rb

@@ -4,7 +4,8 @@ module SolidusPromotions
   module AdjustmentDiscounts
     def discounts_by_lanes(lanes)
       adjustments.select do |adjustment|
-        adjustment.source_type == "SolidusPromotions::Benefit" &&
+        !adjustment.marked_for_destruction? &&
+          adjustment.source_type == "SolidusPromotions::Benefit" &&
           adjustment.source.promotion.lane.to_sym.in?(lanes.map(&:to_sym))
       end
     end

promotions/app/patches/models/solidus_promotions/shipping_rate_patch.rb

@@ -25,7 +25,8 @@ def promo_total
 
     def discounts_by_lanes(lanes)
       discounts.select do |discount|
-        discount.benefit.promotion.lane.to_sym.in?(lanes.map(&:to_sym))
+        !discount.marked_for_destruction? &&
+          discount.benefit.promotion.lane.to_sym.in?(lanes.map(&:to_sym))
       end
     end
 

promotions/spec/models/spree/line_item_spec.rb

@@ -90,6 +90,14 @@
       expect(subject).to contain_exactly(pre_lane_adjustment, post_lane_adjustment)
     end
 
+    context "if adjustment is marked for destruction" do
+      before do
+        pre_lane_adjustment.mark_for_destruction
+      end
+
+      it { is_expected.to contain_exactly(post_lane_adjustment) }
+    end
+
     context "while calculating promotions" do
       around do |example|
         SolidusPromotions::Promotion.within_lane(lane) do

promotions/spec/models/spree/shipment_spec.rb

@@ -90,6 +90,14 @@
       expect(subject).to contain_exactly(pre_lane_adjustment, post_lane_adjustment)
     end
 
+    context "if adjustment is marked for destruction" do
+      before do
+        pre_lane_adjustment.mark_for_destruction
+      end
+
+      it { is_expected.to contain_exactly(post_lane_adjustment) }
+    end
+
     context "while calculating promotions" do
       around do |example|
         SolidusPromotions::Promotion.within_lane(lane) do

promotions/spec/models/spree/shipping_rate_spec.rb

@@ -93,6 +93,14 @@
       expect(subject).to contain_exactly(pre_lane_discount, post_lane_discount)
     end
 
+    context "if discount is marked for destruction" do
+      before do
+        pre_lane_discount.mark_for_destruction
+      end
+
+      it { is_expected.to contain_exactly(post_lane_discount) }
+    end
+
     context "while calculating promotions" do
       around do |example|
         SolidusPromotions::Promotion.within_lane(lane) do