Add migrate order promotions rake task

MIGRATING.md

@@ -51,16 +51,19 @@ Spree::Config.promotion_adjuster_class = "SolidusFriendlyPromotions::OrderDiscou
 
 From a user's perspective, your promotions should work as before.
 
-Before you create new promotions, migrate the adjustments in your database:
+Before you create new promotions, migrate the adjustments and order promotions in your database:
 
 ```rb
 bundle exec rails solidus_friendly_promotions:migrate_adjustments:up
+bundle exec rails solidus_friendly_promotions:migrate_order_promotions:up
+
 ```
 
 Check your `spree_adjustments` table for correctness. If things went wrong, you should be able to roll back with
 
 ```rb
 bundle exec rails solidus_friendly_promotions:migrate_adjustments:down
+bundle exec rails solidus_friendly_promotions:migrate_order_promotions:down
 ```
 
 Both of these tasks only work if every promotion and promotion action have an equivalent in SolidusFrienndlyPromotions. Promotion Actions are connected to their originals using the `SolidusFriendlyPromotions#original_promotion_action_id`, Promotions are connected to their originals using the  `SolidusFriendlyPromotions#original_promotion_id`.

lib/solidus_friendly_promotions/migrate_order_promotions.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module SolidusFriendlyPromotions
+  class MigrateOrderPromotions
+    class << self
+      def up
+        Spree::OrderPromotion.all.each do |order_promotion|
+          friendly_promotion = SolidusFriendlyPromotions::Promotion.find_by!(original_promotion_id: order_promotion.promotion.id)
+          friendly_promotion_code = friendly_promotion.codes.find_by(value: order_promotion.promotion_code.value)
+          SolidusFriendlyPromotions::OrderPromotion.find_or_create_by!(order: order_promotion.order,
+            promotion: friendly_promotion,
+            promotion_code: friendly_promotion_code)
+          order_promotion.destroy!
+        end
+      end
+
+      def down
+        SolidusFriendlyPromotions::OrderPromotion.all.each do |friendly_order_promotion|
+          spree_promotion = friendly_order_promotion.promotion.original_promotion
+          spree_promotion_code = spree_promotion.promotion_codes.find_by(value: friendly_order_promotion.promotion_code.value)
+          Spree::OrderPromotion.find_or_create_by!(order: friendly_order_promotion.order,
+            promotion: spree_promotion,
+            promotion_code: spree_promotion_code)
+          friendly_order_promotion.destroy!
+        end
+      end
+    end
+  end
+end

lib/tasks/solidus_friendly_promotions/migrate_order_promotions.rake

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+namespace :solidus_friendly_promotions do
+  namespace :migrate_order_promotions do
+    desc "Migrate order promotions from Spree::OrderPromotion sources to SolidusFriendlyPromotions::FriendlyOrderPromotion sources"
+    task up: :environment do
+      require "solidus_friendly_promotions/migrate_order_promotions"
+      SolidusFriendlyPromotions::MigrateOrderPromotions.up
+    end
+
+    desc "Migrate order promotions from SolidusFriendlyPromotions::FriendlyOrderPromotion sources to Spree::OrderPromotion sources"
+    task down: :environment do
+      require "solidus_friendly_promotions/migrate_order_promotions"
+      SolidusFriendlyPromotions::MigrateOrderPromotions.down
+    end
+  end
+end

spec/lib/solidus_friendly_promotions/migrate_order_promotions_spec.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "solidus_friendly_promotions/promotion_migrator"
+require "solidus_friendly_promotions/promotion_map"
+require "solidus_friendly_promotions/migrate_order_promotions"
+
+RSpec.describe SolidusFriendlyPromotions::MigrateOrderPromotions do
+  let(:promotion) { create(:promotion, :with_adjustable_action) }
+  let(:order) { create(:order_with_line_items) }
+  let(:line_item) { order.line_items.first }
+  let(:promotion_code) { create(:promotion_code, promotion: promotion) }
+
+  before do
+    order.order_promotions.create!(promotion: promotion, promotion_code: promotion_code)
+    SolidusFriendlyPromotions::PromotionMigrator.new(
+      SolidusFriendlyPromotions::PROMOTION_MAP
+    ).call
+  end
+
+  describe ".up" do
+    subject { described_class.up }
+
+    it "migrates our order promotion" do
+      expect { subject }.to change {
+        Spree::OrderPromotion.count
+      }.from(1).to(0)
+    end
+
+    it "creates our order promotion" do
+      expect { subject }.to change {
+        SolidusFriendlyPromotions::OrderPromotion.count
+      }.from(0).to(1)
+
+      order_promotion = SolidusFriendlyPromotions::OrderPromotion.first
+      expect(order_promotion.order).to eq(order)
+      expect(order_promotion.promotion).to eq(SolidusFriendlyPromotions::Promotion.first)
+      expect(order_promotion.promotion_code.value).to eq(promotion_code.value)
+    end
+  end
+
+  describe ".down" do
+    subject { described_class.down }
+
+    before do
+      described_class.up
+    end
+
+    it "migrates our order promotion" do
+      expect { subject }.to change {
+        Spree::OrderPromotion.count
+      }.from(0).to(1)
+
+      order_promotion = Spree::OrderPromotion.first
+      expect(order_promotion.order).to eq(order)
+      expect(order_promotion.promotion).to eq(promotion)
+      expect(order_promotion.promotion_code).to eq(promotion_code)
+    end
+
+    it "creates our order promotion" do
+      expect { subject }.to change {
+        SolidusFriendlyPromotions::OrderPromotion.count
+      }.from(1).to(0)
+    end
+  end
+end