Merge pull request #1500 from r7kamura/useless-method-def-exclude

Exclude controllers and mailers from `Lint/UselessMethodDefinition`

Author: koic

changelog/change_exclude_controllers_and_mailers_from.md

@@ -0,0 +1 @@
+* [#1500](https://github.com/rubocop/rubocop-rails/pull/1500): Exclude controllers and mailers from `Lint/UselessMethodDefinition`. ([@r7kamura][])

config/default.yml

@@ -91,6 +91,12 @@ Lint/UselessAccessModifier:
     - concern
     - concerning
 
+Lint/UselessMethodDefinition:
+  # Avoids conflict with `Rails/LexicallyScopedActionFilter` cop.
+  Exclude:
+    - '**/app/controllers/**/*.rb'
+    - '**/app/mailers/**/*.rb'
+
 Rails:
   Enabled: true
   DocumentationBaseURL: https://docs.rubocop.org/rubocop-rails