Respect Backlog/Done positions when creating a new list

1 files changed, 19 insertions, 3 deletions

diff --git a/app/services/boards/lists/create_service.rb b/app/services/boards/lists/create_service.rb
index c6b74148ee1..42ab93ad8c4 100644
--- a/app/services/boards/lists/create_service.rb
+++ b/app/services/boards/lists/create_service.rb
@@ -7,15 +7,31 @@ module Boards
       end
 
       def execute
-        board.lists.create(params.merge(position: position))
+        List.transaction do
+          position = find_next_position
+          increment_higher_lists(position)
+          create_list_at(position)
+        end
       end
 
       private
 
       attr_reader :board, :params
 
-      def position
-        board.lists.size
+      def find_next_position
+        return 0 unless board.lists.any?
+
+        records = board.lists.where.not(list_type: List.list_types[:done])
+        records.maximum(:position).to_i + 1
+      end
+
+      def create_list_at(position)
+        board.lists.create(params.merge(list_type: :label, position: position))
+      end
+
+      def increment_higher_lists(position)
+        board.lists.where('position >= ?', position)
+             .update_all('position = position + 1')
       end
     end
   end