useless_setter_call.rb in rubocop-1.2.0

- old
+ new

@@ -3,10 +3,11 @@
 module RuboCop
   module Cop
     module Lint
       # This cop checks for setter call to local variable as the final
       # expression of a function definition.
+      # Its auto-correction is marked as unsafe because return value will be changed.
       #
       # NOTE: There are edge cases in which the local variable references a
       # value that is also accessible outside the local scope. This is not
       # detected by the cop, and it can yield a false positive.
       #
@@ -27,10 +28,12 @@
       #     x = Something.new
       #     x.attr = 5
       #     x
       #   end
       class UselessSetterCall < Base
+        extend AutoCorrector
+
         MSG = 'Useless setter call to local variable `%<variable>s`.'
         ASSIGNMENT_TYPES = %i[lvasgn ivasgn cvasgn gvasgn].freeze
 
         def on_def(node)
           return unless node.body
@@ -43,10 +46,12 @@
           variable_name, = *receiver
           return unless tracker.contain_local_object?(variable_name)
 
           loc_name = receiver.loc.name
 
-          add_offense(loc_name, message: format(MSG, variable: loc_name.source))
+          add_offense(loc_name, message: format(MSG, variable: loc_name.source)) do |corrector|
+            corrector.insert_after(last_expr, "\n#{indent(last_expr)}#{loc_name.source}")
+          end
         end
         alias on_defs on_def
 
         private
 