--- a/config/environments/development.rb	Sat Aug 21 20:46:52 2021 +0900
+++ b/config/environments/development.rb	Sat Jan 15 02:39:53 2022 +0900
@@ -14,15 +14,18 @@
   # Show full error reports.
   config.consider_all_requests_local = true
 
+  # Enable server timing
+  config.server_timing = true
+
   # Enable/disable caching. By default caching is disabled.
   # Run rails dev:cache to toggle caching.
-  if Rails.root.join('tmp', 'caching-dev.txt').exist?
+  if Rails.root.join("tmp/caching-dev.txt").exist?
     config.action_controller.perform_caching = true
     config.action_controller.enable_fragment_cache_logging = true
 
     config.cache_store = :memory_store
     config.public_file_server.headers = {
-      'Cache-Control' => "public, max-age=#{2.days.to_i}"
+      "Cache-Control" => "public, max-age=#{2.days.to_i}"
     }
   else
     config.action_controller.perform_caching = false
@@ -46,10 +49,6 @@
   # Annotate rendered view with file names.
   # config.action_view.annotate_rendered_view_with_filenames = true
 
-  # Use an evented file watcher to asynchronously detect changes in source code,
-  # routes, locales, etc. This feature depends on the listen gem.
-  # config.file_watcher = ActiveSupport::EventedFileUpdateChecker
-
   # Uncomment if you wish to allow Action Cable access from any origin.
   # config.action_cable.disable_request_forgery_protection = true
 end