Activate new rails 6 defaults where able.

config/application.rb

@@ -24,5 +24,9 @@ class Application < Rails::Application
         ENV[key.to_s] = value
       end if File.exist?(env_file)
     end
+
+    # remove after changing load_defaults to 6.0
+    # Uncomment when ready to test out zeitwerk loader
+    # config.autoloader = :zeitwerk
   end
 end

config/initializers/new_framework_defaults_6_0.rb

@@ -7,7 +7,7 @@
 # Read the Guide for Upgrading Ruby on Rails for more info on each option.
 
 # Don't force requests from old versions of IE to be UTF-8 encoded.
-# Rails.application.config.action_view.default_enforce_utf8 = false
+Rails.application.config.action_view.default_enforce_utf8 = false
 
 # Embed purpose and expiry metadata inside signed and encrypted
 # cookies for increased security.
@@ -17,18 +17,18 @@
 # Rails.application.config.action_dispatch.use_cookies_with_metadata = true
 
 # Change the return value of `ActionDispatch::Response#content_type` to Content-Type header without modification.
-# Rails.application.config.action_dispatch.return_only_media_type_on_content_type = false
+Rails.application.config.action_dispatch.return_only_media_type_on_content_type = false
 
 # Return false instead of self when enqueuing is aborted from a callback.
-# Rails.application.config.active_job.return_false_on_aborted_enqueue = true
+Rails.application.config.active_job.return_false_on_aborted_enqueue = true
 
 # Send Active Storage analysis and purge jobs to dedicated queues.
-# Rails.application.config.active_storage.queues.analysis = :active_storage_analysis
-# Rails.application.config.active_storage.queues.purge    = :active_storage_purge
+Rails.application.config.active_storage.queues.analysis = :active_storage_analysis
+Rails.application.config.active_storage.queues.purge    = :active_storage_purge
 
 # When assigning to a collection of attachments declared via `has_many_attached`, replace existing
 # attachments instead of appending. Use #attach to add new attachments without replacing existing ones.
-# Rails.application.config.active_storage.replace_on_assign_to_many = true
+Rails.application.config.active_storage.replace_on_assign_to_many = true
 
 # Use ActionMailer::MailDeliveryJob for sending parameterized and normal mail.
 #
@@ -42,4 +42,4 @@
 # Enable the same cache key to be reused when the object being cached of type
 # `ActiveRecord::Relation` changes by moving the volatile information (max updated at and count)
 # of the relation's cache key into the cache version to support recycling cache key.
-# Rails.application.config.active_record.collection_cache_versioning = true
+Rails.application.config.active_record.collection_cache_versioning = true

test/test_helper.rb

@@ -9,6 +9,8 @@
 Capybara.server = :puma, { Silent: true }
 
 class ActiveSupport::TestCase
+  # Run tests in parallel with specified workers
+  # parallelize(workers: :number_of_processors)
   # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
   fixtures :all