Transparently replace promotion adjustments

app/decorators/models/solidus_friendly_promotions/adjustment_decorator.rb

@@ -4,11 +4,23 @@ module SolidusFriendlyPromotions
   module AdjustmentDecorator
     def self.prepended(base)
       base.scope :friendly_promotion, -> { where(source_type: "SolidusFriendlyPromotions::PromotionAction") }
+      base.scope :promotion, -> { where(source_type: ["SolidusFriendlyPromotions::PromotionAction", "Spree::PromotionAction"]) }
     end
 
     def friendly_promotion?
       source_type == "SolidusFriendlyPromotions::PromotionAction"
     end
+
+    def promotion?
+      super || source_type == "SolidusFriendlyPromotions::PromotionAction"
+    end
+
+    private
+
+    def require_promotion_code?
+      !friendly_promotion? && super
+    end
+
     Spree::Adjustment.prepend self
   end
 end

app/decorators/models/solidus_friendly_promotions/order_decorator.rb

@@ -17,8 +17,7 @@ def ensure_promotions_eligible
         recalculate
         errors.add(:base, I18n.t("solidus_friendly_promotions.promotion_total_changed_before_complete"))
       end
-
-      super
+      errors.empty?
     end
 
     def discountable_item_total

app/models/solidus_friendly_promotions/order_discounter.rb

@@ -44,13 +44,13 @@ def call
     # @param [Array<SolidusFriendlyPromotions::ItemDiscount>] item_discounts a list of calculated discounts for an item
     # @return [void]
     def update_adjustments(item, item_discounts)
-      promotion_adjustments = item.adjustments.select(&:friendly_promotion?)
+      promotion_adjustments = item.adjustments.select(&:promotion?)
 
       active_adjustments = item_discounts.map do |item_discount|
         update_adjustment(item, item_discount)
       end
       item.update(promo_total: active_adjustments.sum(&:amount))
-      # Remove any tax adjustments tied to rates which no longer match.
+      # Remove any tax adjustments tied to promotion actions which no longer match.
       unmatched_adjustments = promotion_adjustments - active_adjustments
 
       item.adjustments.destroy(unmatched_adjustments)

spec/models/solidus_friendly_promotions/order_discounter_spec.rb

@@ -39,6 +39,18 @@
             subject.call
           }.to change { adjustable.adjustments.length }.by(0)
         end
+
+        context "for an line item that has an adjustment from the old promotion system" do
+          let(:old_promotion_action) { create(:promotion, :with_adjustable_action, apply_automatically: false).actions.first }
+          let!(:adjustment) { create(:adjustment, source: old_promotion_action, adjustable: line_item) }
+
+          it "removes the old adjustment from the line item" do
+            adjustable.reload
+            expect {
+              subject.call
+            }.to change { adjustable.reload.adjustments.length }.by(-1)
+          end
+        end
       end
     end
 

spec/models/spree/adjustment_spec.rb

@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe Spree::Adjustment do
+  describe ".promotion" do
+    let(:spree_promotion_action) { create(:promotion, :with_action).actions.first }
+    let!(:spree_promotion_action_adjustment) { create(:adjustment, source: spree_promotion_action) }
+    let(:friendly_promotion_action) { create(:friendly_promotion, :with_adjustable_action).actions.first }
+    let!(:friendly_promotion_action_adjustment) { create(:adjustment, source: friendly_promotion_action) }
+    let(:tax_rate) { create(:tax_rate) }
+    let!(:tax_adjustment) { create(:adjustment, source: tax_rate) }
+
+    subject { described_class.promotion }
+
+    it { is_expected.to contain_exactly(friendly_promotion_action_adjustment, spree_promotion_action_adjustment) }
+  end
+
+  describe ".friendly_promotion" do
+    let(:spree_promotion_action) { create(:promotion, :with_action).actions.first }
+    let!(:spree_promotion_action_adjustment) { create(:adjustment, source: spree_promotion_action) }
+    let(:friendly_promotion_action) { create(:friendly_promotion, :with_adjustable_action).actions.first }
+    let!(:friendly_promotion_action_adjustment) { create(:adjustment, source: friendly_promotion_action) }
+    let(:tax_rate) { create(:tax_rate) }
+    let!(:tax_adjustment) { create(:adjustment, source: tax_rate) }
+
+    subject { described_class.friendly_promotion }
+
+    it { is_expected.to contain_exactly(friendly_promotion_action_adjustment) }
+  end
+
+  describe "#promotion?" do
+    let(:source) { create(:friendly_promotion, :with_adjustable_action).actions.first }
+    let!(:adjustment) { build(:adjustment, source: source) }
+
+    subject { adjustment.promotion? }
+
+    it { is_expected.to be true }
+
+    context "with a Spree Promotion Action source" do
+      let(:source) { create(:promotion, :with_action).actions.first }
+
+      it { is_expected.to be true }
+    end
+
+    context "with a Tax Rate source" do
+      let(:source) { create(:tax_rate) }
+
+      it { is_expected.to be false }
+    end
+  end
+
+  describe "#friendly_promotion?" do
+    let(:source) { create(:friendly_promotion, :with_adjustable_action).actions.first }
+    let!(:adjustment) { build(:adjustment, source: source) }
+
+    subject { adjustment.friendly_promotion? }
+
+    it { is_expected.to be true }
+
+    context "with a Spree Promotion Action source" do
+      let(:source) { create(:promotion, :with_action).actions.first }
+
+      it { is_expected.to be false }
+    end
+
+    context "with a Tax Rate source" do
+      let(:source) { create(:tax_rate) }
+
+      it { is_expected.to be false }
+    end
+  end
+end