Ernie Miller's recommendation for application.rb

application.rb

# config/application.rb
# published at https://ernie.io/2015/06/16/rails-application-rb-recommendations/

config.generators do |g|
  g.assets = false  # stop creating empty asset files for every controller you generate
  g.helper = false  # stop creating empty helper files
end

config.action_controller.include_all_helpers = false  # only include this controller's helpers, do not include all others
config.active_record.schema_format           = :sql   # prevent loss of clarity caused by the lossy schema format

And an interesting comment on Ernie's post:

Kenn Ejima:

I have a different view about include_all_helpers. I turn off generators like you but keep include_all_helpers=true.

I would say instead: Stop creating per-controller helpers. Create helpers to group related methods. I have FlashHelper, AnalyticsHelper, FormHelper, LinkHelper, DisplayHelper, CurrencyHelper, MailerHelper, etc. and those helpers are used in any controllers / views, including layouts.

I even have ControllerHelper to expose small number of view-related methods available in both controllers and views, using "include ControllerHelper" in ApplicationController (directly putting view methods in ApplicationController felt wrong), and MailerHelper is used by "BaseMailer < ActionMailer::Base" which has "helper :mailer". Helpers can include other helpers, so it's easy to nest / group / reuse by meaningful helper module names. In my case, MailerHelper includes LinkHelper and CurrencyHelper.