Improves position by stars logic and fixes that case: given 2 items w…

…ith 5 stars and updating first's stars to 4 then it will be moved to #3.

app/models/user_ranking_item.rb

@@ -25,7 +25,11 @@ def self.position_for_user_by_stars(user_id, ranking_id, user_ranking_item_id, s
     ranking_items = ranking_items.where('id <> ?', user_ranking_item_id) if user_ranking_item_id.present?
 
     if stars.to_i >= 3
-      ranking_items.order('stars ASC, position DESC').where('stars >= ?', stars).first.try(:position).to_i + 1 || 1
+      position = ranking_items.order('stars ASC, position DESC').where('stars >= ?', stars).first.try(:position).to_i + 1 || 1
+
+      position -= 1 if user_ranking_item_id.present? && position > ranking_items_count
+
+      position
     else
       item = ranking_items.order('stars DESC, position ASC').where('stars <= ?', stars).first