Refactored 2 methods to correct stderr output warnings

lib/merit/controller_extensions.rb

@@ -47,15 +47,23 @@ def had_errors?
     end
 
     def target_object
-      target_obj = instance_variable_get(:"@#{controller_name.singularize}")
-      if target_obj.nil?
-        str = '[merit] No object found, you might need a ' \
-          "'@#{controller_name.singularize}' variable in " \
-          "'#{controller_path}_controller' if no reputation is applied. " \
-          'If you are using `model_name` option in the rule this is ok.'
-        Rails.logger.warn str
+      variable_name = :"@#{controller_name.singularize}"
+      if instance_variable_defined?(variable_name)
+        if target_obj = instance_variable_get(variable_name)
+          target_obj
+        else
+          warn_no_object_found
+        end
       end
-      target_obj
+    end
+
+    def warn_no_object_found
+      str = '[merit] No object found, you might need a ' \
+        "'@#{controller_name.singularize}' variable in " \
+        "'#{controller_path}_controller' if no reputation is applied. " \
+        'If you are using `model_name` option in the rule this is ok.'
+      Rails.logger.warn str
+      nil
     end
 
     def target_id

test/dummy/app/models/merit/point_rules.rb

@@ -36,7 +36,7 @@ def initialize
         object.comment.to_i > 0
       end
 
-      score -5, to: :user, on: 'comments#destroy' do |comment|
+      score (-5), to: :user, on: 'comments#destroy' do |comment|
         comment.present?
       end
     end