Add revert and deactivate methods to allow actions to take place when…

core/app/models/spree/promotion.rb

@@ -83,6 +83,33 @@ def activate(payload)
       action_taken
     end
 
+    # Called when a promotion is removed from the cart
+    def deactivate(payload)
+      order = payload[:order]
+      return unless self.class.order_activatable?(order)
+
+      payload[:promotion] = self
+
+      # Track results from actions to see if any action has been taken.
+      # Actions should return nil/false if no action has been taken.
+      # If an action returns true, then an action has been taken.
+      results = actions.map do |action|
+        action.revert(payload) if action.respond_to?(:revert)
+      end
+
+      # If an action has been taken, report back to whatever `d this promotion.
+      action_taken = results.include?(true)
+
+      if action_taken
+        # connect to the order
+        # create the join_table entry.
+        orders << order
+        save
+      end
+
+      action_taken
+    end
+
     # called anytime order.update_with_updater! happens
     def eligible?(promotable)
       return false if expired? || usage_limit_exceeded?(promotable) || blacklisted?(promotable)

core/app/models/spree/promotion/actions/create_line_items.rb

@@ -37,7 +37,7 @@ class CreateLineItems < PromotionAction
         # needs to be manually removed from the order by the customer
         def perform(options = {})
           order = options[:order]
-          return unless self.eligible? order
+          return unless eligible? order
 
           action_taken = false
           promotion_action_line_items.each do |item|
@@ -50,12 +50,30 @@ def perform(options = {})
           action_taken
         end
 
+        # Called by promotion handler when a promotion is removed
+        # This will find any line item matching the ones defined in the PromotionAction
+        # and remove the same quantity as was added by the PromotionAction.
+        # Should help to prevent some of cases listed above the #perform method
+        def revert(options = {})
+          order = options[:order]
+          return if eligible?(order)
+
+          action_taken = false
+          promotion_action_line_items.each do |item|
+            line_item = order.find_line_item_by_variant(item.variant)
+            next unless line_item.present?
+            order.contents.remove(item.variant, (item.quantity || 1))
+            action_taken = true
+          end
+
+          action_taken
+        end
+
         # Checks that there's enough stock to add the line item to the order
         def item_available?(item)
           quantifier = Spree::Stock::Quantifier.new(item.variant)
           quantifier.can_supply? item.quantity
         end
-
       end
     end
   end

core/app/models/spree/promotion_handler/cart.rb

@@ -24,6 +24,8 @@ def activate
         promotions.each do |promotion|
           if (line_item && promotion.eligible?(line_item)) || promotion.eligible?(order)
             promotion.activate(line_item: line_item, order: order)
+          else
+            promotion.deactivate(line_item: line_item, order: order)
           end
         end
       end