diff --git a/actionmailbox/test/dummy/Rakefile b/actionmailbox/test/dummy/Rakefile
index e85f913914b..9a5ea7383aa 100644
--- a/actionmailbox/test/dummy/Rakefile
+++ b/actionmailbox/test/dummy/Rakefile
@@ -1,6 +1,6 @@
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require_relative 'config/application'
+require_relative "config/application"
 
 Rails.application.load_tasks
diff --git a/actionmailbox/test/dummy/bin/rails b/actionmailbox/test/dummy/bin/rails
index 07396602377..6fb4e4051c4 100755
--- a/actionmailbox/test/dummy/bin/rails
+++ b/actionmailbox/test/dummy/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
 APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/actionmailbox/test/dummy/bin/rake b/actionmailbox/test/dummy/bin/rake
index 17240489f64..4fbf10b960e 100755
--- a/actionmailbox/test/dummy/bin/rake
+++ b/actionmailbox/test/dummy/bin/rake
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-require_relative '../config/boot'
-require 'rake'
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/actionmailbox/test/dummy/bin/setup b/actionmailbox/test/dummy/bin/setup
index f978895d31e..641207e03c4 100755
--- a/actionmailbox/test/dummy/bin/setup
+++ b/actionmailbox/test/dummy/bin/setup
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-require 'fileutils'
+require "fileutils"
 include FileUtils
 
 # path to your application root.
diff --git a/actionmailbox/test/dummy/bin/update b/actionmailbox/test/dummy/bin/update
index 58bfaed518c..610b83448d2 100755
--- a/actionmailbox/test/dummy/bin/update
+++ b/actionmailbox/test/dummy/bin/update
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-require 'fileutils'
+require "fileutils"
 include FileUtils
 
 # path to your application root.
diff --git a/actionmailbox/test/dummy/config.ru b/actionmailbox/test/dummy/config.ru
index f7ba0b527b1..441e6ff0c3c 100644
--- a/actionmailbox/test/dummy/config.ru
+++ b/actionmailbox/test/dummy/config.ru
@@ -1,5 +1,5 @@
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
diff --git a/actionmailbox/test/dummy/config/application.rb b/actionmailbox/test/dummy/config/application.rb
index ea8ab1fc5e8..8948a9fa45a 100644
--- a/actionmailbox/test/dummy/config/application.rb
+++ b/actionmailbox/test/dummy/config/application.rb
@@ -1,6 +1,6 @@
-require_relative 'boot'
+require_relative "boot"
 
-require 'rails/all'
+require "rails/all"
 
 Bundler.require(*Rails.groups)
 
diff --git a/actionmailbox/test/dummy/config/boot.rb b/actionmailbox/test/dummy/config/boot.rb
index c9aef85d404..91e50810ef7 100644
--- a/actionmailbox/test/dummy/config/boot.rb
+++ b/actionmailbox/test/dummy/config/boot.rb
@@ -1,5 +1,5 @@
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../Gemfile', __dir__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
 $LOAD_PATH.unshift File.expand_path('../../../lib', __dir__)
diff --git a/actionmailbox/test/dummy/config/environment.rb b/actionmailbox/test/dummy/config/environment.rb
index 426333bb469..cac53157752 100644
--- a/actionmailbox/test/dummy/config/environment.rb
+++ b/actionmailbox/test/dummy/config/environment.rb
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/actionmailbox/test/dummy/config/environments/production.rb b/actionmailbox/test/dummy/config/environments/production.rb
index 932858fdb65..33ce2e01869 100644
--- a/actionmailbox/test/dummy/config/environments/production.rb
+++ b/actionmailbox/test/dummy/config/environments/production.rb
@@ -80,7 +80,7 @@ Rails.application.configure do
   config.log_formatter = ::Logger::Formatter.new
 
   # Use a different logger for distributed setups.
-  # require 'syslog/logger'
+  # require "syslog/logger"
   # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
diff --git a/actionpack/lib/action_controller/metal/http_authentication.rb b/actionpack/lib/action_controller/metal/http_authentication.rb
index de8dca086aa..e0ff01e9ec1 100644
--- a/actionpack/lib/action_controller/metal/http_authentication.rb
+++ b/actionpack/lib/action_controller/metal/http_authentication.rb
@@ -136,7 +136,7 @@ module ActionController
     #
     # === Simple \Digest example
     #
-    #   require 'digest/md5'
+    #   require "digest/md5"
     #   class PostsController < ApplicationController
     #     REALM = "SuperSecret"
     #     USERS = {"dhh" => "secret", #plain text password
diff --git a/actionpack/lib/action_dispatch/journey/parser.rb b/actionpack/lib/action_dispatch/journey/parser.rb
index e002755bcf9..9418b87b402 100644
--- a/actionpack/lib/action_dispatch/journey/parser.rb
+++ b/actionpack/lib/action_dispatch/journey/parser.rb
@@ -4,7 +4,7 @@
 # from Racc grammar file "".
 #
 
-require 'racc/parser.rb'
+require "racc/parser.rb"
 
 # :stopdoc:
 
diff --git a/actionpack/lib/action_dispatch/system_test_case.rb b/actionpack/lib/action_dispatch/system_test_case.rb
index 468add91f32..5645544545e 100644
--- a/actionpack/lib/action_dispatch/system_test_case.rb
+++ b/actionpack/lib/action_dispatch/system_test_case.rb
@@ -27,7 +27,7 @@ module ActionDispatch
   #
   # Here is an example system test:
   #
-  #   require 'application_system_test_case'
+  #   require "application_system_test_case"
   #
   #   class Users::CreateTest < ApplicationSystemTestCase
   #     test "adding a new user" do
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index 578a78c40a1..bb6c170afd8 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -513,7 +513,7 @@ module ActionDispatch
   #
   # A simple integration test that exercises multiple controllers:
   #
-  #   require 'test_helper'
+  #   require "test_helper"
   #
   #   class UserFlowsTest < ActionDispatch::IntegrationTest
   #     test "login and browse site" do
@@ -542,7 +542,7 @@ module ActionDispatch
   #
   # Here's an example of multiple sessions and custom DSL in an integration test
   #
-  #   require 'test_helper'
+  #   require "test_helper"
   #
   #   class UserFlowsTest < ActionDispatch::IntegrationTest
   #     test "login and browse site" do
diff --git a/actiontext/test/dummy/Rakefile b/actiontext/test/dummy/Rakefile
index e85f913914b..9a5ea7383aa 100644
--- a/actiontext/test/dummy/Rakefile
+++ b/actiontext/test/dummy/Rakefile
@@ -1,6 +1,6 @@
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require_relative 'config/application'
+require_relative "config/application"
 
 Rails.application.load_tasks
diff --git a/actiontext/test/dummy/bin/rails b/actiontext/test/dummy/bin/rails
index 07396602377..6fb4e4051c4 100755
--- a/actiontext/test/dummy/bin/rails
+++ b/actiontext/test/dummy/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
 APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/actiontext/test/dummy/bin/rake b/actiontext/test/dummy/bin/rake
index 17240489f64..4fbf10b960e 100755
--- a/actiontext/test/dummy/bin/rake
+++ b/actiontext/test/dummy/bin/rake
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-require_relative '../config/boot'
-require 'rake'
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/actiontext/test/dummy/bin/setup b/actiontext/test/dummy/bin/setup
index f978895d31e..641207e03c4 100755
--- a/actiontext/test/dummy/bin/setup
+++ b/actiontext/test/dummy/bin/setup
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-require 'fileutils'
+require "fileutils"
 include FileUtils
 
 # path to your application root.
diff --git a/actiontext/test/dummy/bin/update b/actiontext/test/dummy/bin/update
index 58bfaed518c..610b83448d2 100755
--- a/actiontext/test/dummy/bin/update
+++ b/actiontext/test/dummy/bin/update
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-require 'fileutils'
+require "fileutils"
 include FileUtils
 
 # path to your application root.
diff --git a/actiontext/test/dummy/config.ru b/actiontext/test/dummy/config.ru
index f7ba0b527b1..441e6ff0c3c 100644
--- a/actiontext/test/dummy/config.ru
+++ b/actiontext/test/dummy/config.ru
@@ -1,5 +1,5 @@
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
diff --git a/actiontext/test/dummy/config/application.rb b/actiontext/test/dummy/config/application.rb
index 79eeb6ba0e1..27eb1ad2959 100644
--- a/actiontext/test/dummy/config/application.rb
+++ b/actiontext/test/dummy/config/application.rb
@@ -1,6 +1,6 @@
-require_relative 'boot'
+require_relative "boot"
 
-require 'rails/all'
+require "rails/all"
 
 Bundler.require(*Rails.groups)
 require "action_text"
diff --git a/actiontext/test/dummy/config/boot.rb b/actiontext/test/dummy/config/boot.rb
index c9aef85d404..91e50810ef7 100644
--- a/actiontext/test/dummy/config/boot.rb
+++ b/actiontext/test/dummy/config/boot.rb
@@ -1,5 +1,5 @@
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../Gemfile', __dir__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
 $LOAD_PATH.unshift File.expand_path('../../../lib', __dir__)
diff --git a/actiontext/test/dummy/config/environment.rb b/actiontext/test/dummy/config/environment.rb
index 426333bb469..cac53157752 100644
--- a/actiontext/test/dummy/config/environment.rb
+++ b/actiontext/test/dummy/config/environment.rb
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/actiontext/test/dummy/config/environments/production.rb b/actiontext/test/dummy/config/environments/production.rb
index 2aaa79f6205..ecb8c0b4fce 100644
--- a/actiontext/test/dummy/config/environments/production.rb
+++ b/actiontext/test/dummy/config/environments/production.rb
@@ -82,7 +82,7 @@ Rails.application.configure do
   config.log_formatter = ::Logger::Formatter.new
 
   # Use a different logger for distributed setups.
-  # require 'syslog/logger'
+  # require "syslog/logger"
   # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 40569751289..d4d4b3f1b70 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -59,7 +59,7 @@ module ActiveRecord
   # Since fixtures are a testing construct, we use them in our unit and functional tests. There
   # are two ways to use the fixtures, but first let's take a look at a sample unit test:
   #
-  #   require 'test_helper'
+  #   require "test_helper"
   #
   #   class WebSiteTest < ActiveSupport::TestCase
   #     test "web_site_count" do
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index 0106a7c4192..a293a19138f 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -691,7 +691,7 @@ module ActiveRecord
     # Or equivalently, if +TenderloveMigration+ is defined as in the
     # documentation for Migration:
     #
-    #   require_relative '20121212123456_tenderlove_migration'
+    #   require_relative "20121212123456_tenderlove_migration"
     #
     #   class FixupTLMigration < ActiveRecord::Migration[6.0]
     #     def change
diff --git a/activestorage/test/dummy/config/environments/production.rb b/activestorage/test/dummy/config/environments/production.rb
index be7f5b80d4a..71d4ce3c8d8 100644
--- a/activestorage/test/dummy/config/environments/production.rb
+++ b/activestorage/test/dummy/config/environments/production.rb
@@ -69,7 +69,7 @@ Rails.application.configure do
   config.log_formatter = ::Logger::Formatter.new
 
   # Use a different logger for distributed setups.
-  # require 'syslog/logger'
+  # require "syslog/logger"
   # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
diff --git a/activesupport/lib/active_support/concern.rb b/activesupport/lib/active_support/concern.rb
index 1a192ace5e6..e15d9ced34a 100644
--- a/activesupport/lib/active_support/concern.rb
+++ b/activesupport/lib/active_support/concern.rb
@@ -19,7 +19,7 @@ module ActiveSupport
   # By using <tt>ActiveSupport::Concern</tt> the above module could instead be
   # written as:
   #
-  #   require 'active_support/concern'
+  #   require "active_support/concern"
   #
   #   module M
   #     extend ActiveSupport::Concern
@@ -76,7 +76,7 @@ module ActiveSupport
   # is the +Bar+ module, not the +Host+ class. With <tt>ActiveSupport::Concern</tt>,
   # module dependencies are properly resolved:
   #
-  #   require 'active_support/concern'
+  #   require "active_support/concern"
   #
   #   module Foo
   #     extend ActiveSupport::Concern
diff --git a/activesupport/lib/active_support/configurable.rb b/activesupport/lib/active_support/configurable.rb
index 71c23dae9bf..22bd8d1920d 100644
--- a/activesupport/lib/active_support/configurable.rb
+++ b/activesupport/lib/active_support/configurable.rb
@@ -126,7 +126,7 @@ module ActiveSupport
 
     # Reads and writes attributes from a configuration <tt>OrderedHash</tt>.
     #
-    #   require 'active_support/configurable'
+    #   require "active_support/configurable"
     #
     #   class User
     #     include ActiveSupport::Configurable
diff --git a/guides/source/3_2_release_notes.md b/guides/source/3_2_release_notes.md
index 9aacbb79c09..20f6a8f797c 100644
--- a/guides/source/3_2_release_notes.md
+++ b/guides/source/3_2_release_notes.md
@@ -64,8 +64,8 @@ Replace the code beneath the comment in `script/rails` with the following conten
 ENGINE_ROOT = File.expand_path('../..', __FILE__)
 ENGINE_PATH = File.expand_path('../../lib/your_engine_name/engine', __FILE__)
 
-require 'rails/all'
-require 'rails/engine/commands'
+require "rails/all"
+require "rails/engine/commands"
 ```
 
 Creating a Rails 3.2 application
diff --git a/guides/source/action_cable_overview.md b/guides/source/action_cable_overview.md
index 35e9f527354..44183082e03 100644
--- a/guides/source/action_cable_overview.md
+++ b/guides/source/action_cable_overview.md
@@ -799,7 +799,7 @@ basic setup is as follows:
 
 ```ruby
 # cable/config.ru
-require_relative '../config/environment'
+require_relative "../config/environment"
 Rails.application.eager_load!
 
 run ActionCable.server
diff --git a/guides/source/active_model_basics.md b/guides/source/active_model_basics.md
index 0a83ec16983..a7ed0df01b9 100644
--- a/guides/source/active_model_basics.md
+++ b/guides/source/active_model_basics.md
@@ -425,7 +425,7 @@ the Active Model API.
 * `test/models/person_test.rb`
 
     ```ruby
-    require 'test_helper'
+    require "test_helper"
 
     class PersonTest < ActiveSupport::TestCase
       include ActiveModel::Lint::Tests
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md
index ced031cd6cc..67b4414ccd3 100644
--- a/guides/source/active_record_migrations.md
+++ b/guides/source/active_record_migrations.md
@@ -672,7 +672,7 @@ can't be done.
 You can use Active Record's ability to rollback migrations using the `revert` method:
 
 ```ruby
-require_relative '20121212123456_example_migration'
+require_relative "20121212123456_example_migration"
 
 class FixupExampleMigration < ActiveRecord::Migration[6.0]
   def change
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index edc8e1cfc91..250a1ece1d8 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -26,7 +26,7 @@ In order to have a near-zero default footprint, Active Support does not load any
 Thus, after a simple require like:
 
 ```ruby
-require 'active_support'
+require "active_support"
 ```
 
 objects do not even respond to `blank?`. Let's see how to load its definition.
@@ -42,8 +42,8 @@ NOTE: Defined in `active_support/core_ext/object/blank.rb`.
 That means that you can require it like this:
 
 ```ruby
-require 'active_support'
-require 'active_support/core_ext/object/blank'
+require "active_support"
+require "active_support/core_ext/object/blank"
 ```
 
 Active Support has been carefully revised so that cherry-picking a file loads only strictly needed dependencies, if any.
@@ -55,8 +55,8 @@ The next level is to simply load all extensions to `Object`. As a rule of thumb,
 Thus, to load all extensions to `Object` (including `blank?`):
 
 ```ruby
-require 'active_support'
-require 'active_support/core_ext/object'
+require "active_support"
+require "active_support/core_ext/object"
 ```
 
 #### Loading All Core Extensions
@@ -64,8 +64,8 @@ require 'active_support/core_ext/object'
 You may prefer just to load all core extensions, there is a file for that:
 
 ```ruby
-require 'active_support'
-require 'active_support/core_ext'
+require "active_support"
+require "active_support/core_ext"
 ```
 
 #### Loading All Active Support
@@ -73,7 +73,7 @@ require 'active_support/core_ext'
 And finally, if you want to have all Active Support available just issue:
 
 ```ruby
-require 'active_support/all'
+require "active_support/all"
 ```
 
 That does not even put the entire Active Support in memory upfront indeed, some stuff is configured via `autoload`, so it is only loaded if used.
diff --git a/guides/source/autoloading_and_reloading_constants_classic_mode.md b/guides/source/autoloading_and_reloading_constants_classic_mode.md
index efe779c657c..8d2bdc59f28 100644
--- a/guides/source/autoloading_and_reloading_constants_classic_mode.md
+++ b/guides/source/autoloading_and_reloading_constants_classic_mode.md
@@ -27,8 +27,8 @@ Ruby on Rails allows applications to be written as if their code was preloaded.
 In a normal Ruby program classes need to load their dependencies:
 
 ```ruby
-require 'application_controller'
-require 'post'
+require "application_controller"
+require "post"
 
 class PostsController < ApplicationController
   def index
@@ -440,7 +440,7 @@ autoload_paths and eager_load_paths
 As you probably know, when `require` gets a relative file name:
 
 ```ruby
-require 'erb'
+require "erb"
 ```
 
 Ruby looks for the file in the directories listed in `$LOAD_PATH`. That is, Ruby
@@ -1030,7 +1030,7 @@ have to know all its descendants.
 Files defining constants to be autoloaded should never be `require`d:
 
 ```ruby
-require 'user' # DO NOT DO THIS
+require "user" # DO NOT DO THIS
 
 class UsersController < ApplicationController
   ...
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 7d00377ff15..b39a3eef345 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -25,7 +25,7 @@ Rails offers four standard spots to place initialization code:
 Running Code Before Rails
 -------------------------
 
-In the rare event that your application needs to run some code before Rails itself is loaded, put it above the call to `require 'rails/all'` in `config/application.rb`.
+In the rare event that your application needs to run some code before Rails itself is loaded, put it above the call to `require "rails/all"` in `config/application.rb`.
 
 Configuring Rails Components
 ----------------------------
diff --git a/guides/source/engines.md b/guides/source/engines.md
index d33bf8ce693..9c56a67ec52 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -1417,8 +1417,8 @@ required, you should require them before the engine's initialization. For
 example:
 
 ```ruby
-require 'other_engine/engine'
-require 'yet_another_engine/engine'
+require "other_engine/engine"
+require "yet_another_engine/engine"
 
 module MyEngine
   class Engine < ::Rails::Engine
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index 9d62c39dde3..83552d46d7a 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -75,8 +75,8 @@ This file is as follows:
 ```ruby
 #!/usr/bin/env ruby
 APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+require_relative "../config/boot"
+require "rails/commands"
 ```
 
 The `APP_PATH` constant will be used later in `rails/commands`. The `config/boot` file referenced here is the `config/boot.rb` file in our application which is responsible for loading Bundler and setting it up.
@@ -88,7 +88,7 @@ The `APP_PATH` constant will be used later in `rails/commands`. The `config/boot
 ```ruby
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
-require 'bundler/setup' # Set up gems listed in the Gemfile.
+require "bundler/setup" # Set up gems listed in the Gemfile.
 ```
 
 In a standard Rails application, there's a `Gemfile` which declares all
@@ -410,7 +410,7 @@ module Rack
 
       if options[:debug]
         $DEBUG = true
-        require 'pp'
+        require "pp"
         p options[:server]
         pp wrapped_app
         pp app
@@ -490,7 +490,7 @@ The `options[:config]` value defaults to `config.ru` which contains this:
 ```ruby
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
 ```
@@ -522,7 +522,7 @@ This is where the majority of the initialization process of Rails happens.
 The `require` line for `config/environment.rb` in `config.ru` is the first to run:
 
 ```ruby
-require_relative 'config/environment'
+require_relative "config/environment"
 ```
 
 ### `config/environment.rb`
@@ -532,7 +532,7 @@ This file is the common file required by `config.ru` (`rails server`) and Passen
 This file begins with requiring `config/application.rb`:
 
 ```ruby
-require_relative 'application'
+require_relative "application"
 ```
 
 ### `config/application.rb`
@@ -540,7 +540,7 @@ require_relative 'application'
 This file requires `config/boot.rb`:
 
 ```ruby
-require_relative 'boot'
+require_relative "boot"
 ```
 
 But only if it hasn't been required before, which would be the case in `rails server`
@@ -554,7 +554,7 @@ Loading Rails
 The next line in `config/application.rb` is:
 
 ```ruby
-require 'rails/all'
+require "rails/all"
 ```
 
 ### `railties/lib/rails/all.rb`
diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md
index 62b50bc97cb..e9f23194f64 100644
--- a/guides/source/rails_on_rack.md
+++ b/guides/source/rails_on_rack.md
@@ -64,7 +64,7 @@ To use `rackup` instead of Rails' `rails server`, you can put the following insi
 
 ```ruby
 # Rails.root/config.ru
-require_relative 'config/environment'
+require_relative "config/environment"
 run Rails.application
 ```
 
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 682f9bc9cae..ea0ddf0716a 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -81,7 +81,7 @@ create  test/fixtures/articles.yml
 The default test stub in `test/models/article_test.rb` looks like this:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ArticleTest < ActiveSupport::TestCase
   # test "the truth" do
@@ -93,7 +93,7 @@ end
 A line by line examination of this file will help get you oriented to Rails testing code and terminology.
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 ```
 
 By requiring this file, `test_helper.rb` the default configuration to run our tests is loaded. We will include this with all the tests we write, so any methods added to this file are available to all our tests.
@@ -943,7 +943,7 @@ $ bin/rails generate integration_test user_flows
 Here's what a freshly generated integration test looks like:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class UserFlowsTest < ActionDispatch::IntegrationTest
   # test "the truth" do
@@ -985,7 +985,7 @@ previous command we should see:
 Now let's open that file and write our first assertion:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class BlogFlowTest < ActionDispatch::IntegrationTest
   test "can see the welcome page" do
@@ -1348,7 +1348,7 @@ Notice we're starting to see some duplication in these three tests, they both ac
 Our test should now look something as what follows. Disregard the other tests for now, we're leaving them out for brevity.
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ArticlesControllerTest < ActionDispatch::IntegrationTest
   # called before every single test
@@ -1409,7 +1409,7 @@ end
 ```
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ProfileControllerTest < ActionDispatch::IntegrationTest
 
@@ -1440,8 +1440,8 @@ end
 These helpers can then be explicitly required as needed and included as needed
 
 ```ruby
-require 'test_helper'
-require 'test_helpers/multiple_assertions'
+require "test_helper"
+require "test_helpers/multiple_assertions"
 
 class NumberTest < ActiveSupport::TestCase
   include MultipleAssertions
@@ -1456,7 +1456,7 @@ or they can continue to be included directly into the relevant parent classes
 
 ```ruby
 # test/test_helper.rb
-require 'test_helpers/sign_in_helper'
+require "test_helpers/sign_in_helper"
 
 class ActionDispatch::IntegrationTest
   include SignInHelper
@@ -1616,7 +1616,7 @@ If you generated your mailer, the generator does not create stub fixtures for th
 Here's a unit test to test a mailer named `UserMailer` whose action `invite` is used to send an invitation to a friend. It is an adapted version of the base test created by the generator for an `invite` action.
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class UserMailerTest < ActionMailer::TestCase
   test "invite" do
@@ -1675,7 +1675,7 @@ Unit testing allows us to test the attributes of the email while functional and
 
 ```ruby
 # Integration Test
-require 'test_helper'
+require "test_helper"
 
 class UsersControllerTest < ActionDispatch::IntegrationTest
   test "invite friend" do
@@ -1689,7 +1689,7 @@ end
 
 ```ruby
 # System Test
-require 'test_helper'
+require "test_helper"
 
 class UsersTest < ActionDispatch::SystemTestCase
   driven_by :selenium, using: :headless_chrome
@@ -1719,7 +1719,7 @@ By default, when you generate a job, an associated test will be generated as wel
 under the `test/jobs` directory. Here's an example test with a billing job:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class BillingJobTest < ActiveJob::TestCase
   test 'that account is charged' do
@@ -1747,7 +1747,7 @@ the custom assertions provided by Active Job are pretty useful. For instance,
 within a model:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ProductTest < ActiveSupport::TestCase
   include ActiveJob::TestHelper
@@ -1765,7 +1765,7 @@ end
 When serializing job arguments, `Time`, `DateTime`, and `ActiveSupport::TimeWithZone` lose microsecond precision. This means comparing deserialized time with actual time doesn't always work. To compensate for the loss of precision, `assert_enqueued_with` and `assert_performed_with` will remove microseconds from time objects in argument assertions.
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ProductTest < ActiveSupport::TestCase
   include ActiveJob::TestHelper
@@ -1874,7 +1874,7 @@ the custom assertions provided by Action Cable are pretty useful. For instance,
 within a model:
 
 ```ruby
-require 'test_helper'
+require "test_helper"
 
 class ProductTest < ActionCable::TestCase
   test "broadcast status after charge" do
@@ -1897,7 +1897,7 @@ class ChatRelayJob < ApplicationJob
 end
 
 # test/jobs/chat_relay_job_test.rb
-require 'test_helper'
+require "test_helper"
 
 class ChatRelayJobTest < ActiveJob::TestCase
   include ActionCable::TestHelper
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index ffec12273cb..8b33a4e4d62 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -1234,7 +1234,7 @@ secrets, you need to:
 
 If your test helper contains a call to
 `ActiveRecord::Migration.check_pending!` this can be removed. The check
-is now done automatically when you `require 'rails/test_help'`, although
+is now done automatically when you `require "rails/test_help"`, although
 leaving this line in your helper is not harmful in any way.
 
 ### Cookies serializer
diff --git a/railties/lib/rails/generators/rails/app/templates/Rakefile.tt b/railties/lib/rails/generators/rails/app/templates/Rakefile.tt
index e85f913914b..9a5ea7383aa 100644
--- a/railties/lib/rails/generators/rails/app/templates/Rakefile.tt
+++ b/railties/lib/rails/generators/rails/app/templates/Rakefile.tt
@@ -1,6 +1,6 @@
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require_relative 'config/application'
+require_relative "config/application"
 
 Rails.application.load_tasks
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/rails.tt b/railties/lib/rails/generators/rails/app/templates/bin/rails.tt
index 513a2e0183c..d601e5e533d 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/rails.tt
+++ b/railties/lib/rails/generators/rails/app/templates/bin/rails.tt
@@ -1,3 +1,3 @@
 APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/rake.tt b/railties/lib/rails/generators/rails/app/templates/bin/rake.tt
index d14fc8395bc..aaf0552684d 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/rake.tt
+++ b/railties/lib/rails/generators/rails/app/templates/bin/rake.tt
@@ -1,3 +1,3 @@
-require_relative '../config/boot'
-require 'rake'
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/setup.tt b/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
index ed0521853b6..368d947287d 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
+++ b/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
@@ -1,4 +1,4 @@
-require 'fileutils'
+require "fileutils"
 
 # path to your application root.
 APP_ROOT = File.expand_path('..', __dir__)
diff --git a/railties/lib/rails/generators/rails/app/templates/config.ru.tt b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
index f7ba0b527b1..441e6ff0c3c 100644
--- a/railties/lib/rails/generators/rails/app/templates/config.ru.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
@@ -1,5 +1,5 @@
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
diff --git a/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt
index 1b5fe12ed49..bdab297d829 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt
@@ -1,7 +1,7 @@
-require_relative 'boot'
+require_relative "boot"
 
 <% if include_all_railties? -%>
-require 'rails/all'
+require "rails/all"
 <% else -%>
 require "rails"
 # Pick the frameworks you want:
diff --git a/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt
index 42d46b81755..cdefe1d6d9d 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt
@@ -1,6 +1,6 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
-require 'bundler/setup' # Set up gems listed in the Gemfile.
+require "bundler/setup" # Set up gems listed in the Gemfile.
 <% if depend_on_bootsnap? -%>
-require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
+require "bootsnap/setup" # Speed up boot time by caching expensive operations.
 <%- end -%>
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt
index 426333bb469..cac53157752 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
index 87273299bc3..7d0f668e34c 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
@@ -93,7 +93,7 @@ Rails.application.configure do
   config.log_formatter = ::Logger::Formatter.new
 
   # Use a different logger for distributed setups.
-  # require 'syslog/logger'
+  # require "syslog/logger"
   # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
diff --git a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt
index 47b4cf745cd..cc677ab4115 100644
--- a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt
@@ -1,6 +1,6 @@
 ENV['RAILS_ENV'] ||= 'test'
-require_relative '../config/environment'
-require 'rails/test_help'
+require_relative "../config/environment"
+require "rails/test_help"
 
 class ActiveSupport::TestCase
   # Run tests in parallel with specified workers
diff --git a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
index f437689fcac..19758afd8ee 100644
--- a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
+++ b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
@@ -401,7 +401,7 @@ task default: :test
 
       def rakefile_test_tasks
         <<-RUBY
-require 'rake/testtask'
+require "rake/testtask"
 
 Rake::TestTask.new(:test) do |t|
   t.libs << 'test'
diff --git a/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt b/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt
index 92087351c5e..7ddff35cfe7 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt
@@ -1,5 +1,5 @@
-require 'bundler/setup'
-require 'rdoc/task'
+require "bundler/setup"
+require "rdoc/task"
 
 RDoc::Task.new(:rdoc) do |rdoc|
   rdoc.rdoc_dir = 'rdoc'
@@ -11,13 +11,13 @@ end
 <% if engine? && !options[:skip_active_record] && with_dummy_app? -%>
 
 APP_RAKEFILE = File.expand_path("<%= dummy_path -%>/Rakefile", __dir__)
-load 'rails/tasks/engine.rake'
+load "rails/tasks/engine.rake"
 <% end -%>
 <% if engine? -%>
 
-load 'rails/tasks/statistics.rake'
+load "rails/tasks/statistics.rake"
 <% end -%>
 <% unless options[:skip_gemspec] -%>
 
-require 'bundler/gem_tasks'
+require "bundler/gem_tasks"
 <% end -%>
diff --git a/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt b/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt
index ee8e469da21..fd4e35480cc 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt
@@ -9,10 +9,10 @@ APP_PATH = File.expand_path('../<%= dummy_path -%>/config/application', __dir__)
 
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
 
 <% if include_all_railties? -%>
-require 'rails/all'
+require "rails/all"
 <% else -%>
 require "rails"
 # Pick the frameworks you want:
@@ -27,4 +27,4 @@ require "action_view/railtie"
 <%= comment_if :skip_sprockets %>require "sprockets/railtie"
 <%= comment_if :skip_test %>require "rails/test_unit/railtie"
 <% end -%>
-require 'rails/engine/commands'
+require "rails/engine/commands"
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt
index 06ffe2f1ed0..6c05a1f2ada 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt
@@ -1,7 +1,7 @@
-require_relative 'boot'
+require_relative "boot"
 
 <% if include_all_railties? -%>
-require 'rails/all'
+require "rails/all"
 <% else -%>
 require "rails"
 # Pick the frameworks you want:
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt
index c9aef85d404..91e50810ef7 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt
@@ -1,5 +1,5 @@
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../Gemfile', __dir__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
 $LOAD_PATH.unshift File.expand_path('../../../lib', __dir__)
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt
index 1ee05d78715..d2317af74cb 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 class <%= camelized_modules %>::Test < ActiveSupport::TestCase
   test "truth" do
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt
index 29e59d84077..ebbc098ac9d 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 class NavigationTest < ActionDispatch::IntegrationTest
   # test "the truth" do
diff --git a/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt b/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt
index 29e41d0411d..55ba9ae7130 100644
--- a/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= class_name %>ControllerTest < ActionDispatch::IntegrationTest
diff --git a/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt b/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt
index a7f1fc4fba5..5b07e57dbdc 100644
--- a/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt
@@ -1,5 +1,5 @@
-require 'test_helper'
-require '<%= generator_path %>'
+require "test_helper"
+require "<%= generator_path %>"
 
 <% module_namespacing do -%>
 class <%= class_name %>GeneratorTest < Rails::Generators::TestCase
diff --git a/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt b/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt
index 118e0f1271d..e2ab3938415 100644
--- a/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= class_name %>Test < ActionDispatch::IntegrationTest
diff --git a/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt b/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt
index f5351d0ec63..96d30b350b3 100644
--- a/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= class_name %>JobTest < ActiveJob::TestCase
diff --git a/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt b/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt
index a2f2d30de52..c7b576ba623 100644
--- a/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= class_name %>MailerTest < ActionMailer::TestCase
diff --git a/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt b/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt
index c9bc7d5b90c..7d3ce602c33 100644
--- a/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= class_name %>Test < ActiveSupport::TestCase
diff --git a/railties/lib/rails/generators/test_unit/plugin/templates/%file_name%_test.rb.tt b/railties/lib/rails/generators/test_unit/plugin/templates/%file_name%_test.rb.tt
index 0cbae1120e0..39eb17ce544 100644
--- a/railties/lib/rails/generators/test_unit/plugin/templates/%file_name%_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/plugin/templates/%file_name%_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 class <%= class_name %>Test < ActiveSupport::TestCase
   # test "the truth" do
diff --git a/railties/lib/rails/generators/test_unit/plugin/templates/test_helper.rb b/railties/lib/rails/generators/test_unit/plugin/templates/test_helper.rb
index 30a861f09dc..4eb3868c6b8 100644
--- a/railties/lib/rails/generators/test_unit/plugin/templates/test_helper.rb
+++ b/railties/lib/rails/generators/test_unit/plugin/templates/test_helper.rb
@@ -1,2 +1,2 @@
-require 'active_support/testing/autorun'
-require 'active_support'
+require "active_support/testing/autorun"
+require "active_support"
diff --git a/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt b/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt
index f21861d8e68..068b4f934e0 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= controller_class_name %>ControllerTest < ActionDispatch::IntegrationTest
diff --git a/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt b/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt
index 195d60be206..6704c8c0256 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt
+++ b/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt
@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 <% module_namespacing do -%>
 class <%= controller_class_name %>ControllerTest < ActionDispatch::IntegrationTest
diff --git a/railties/lib/rails/railtie.rb b/railties/lib/rails/railtie.rb
index bf3a0d3f86e..baf1c167478 100644
--- a/railties/lib/rails/railtie.rb
+++ b/railties/lib/rails/railtie.rb
@@ -42,7 +42,7 @@ module Rails
   #   end
   #
   #   # lib/my_gem.rb
-  #   require 'my_gem/railtie' if defined?(Rails::Railtie)
+  #   require "my_gem/railtie" if defined?(Rails::Railtie)
   #
   # == Initializers
   #
@@ -91,7 +91,7 @@ module Rails
   #
   #   class MyRailtie < Rails::Railtie
   #     rake_tasks do
-  #       load 'path/to/my_railtie.tasks'
+  #       load "path/to/my_railtie.tasks"
   #     end
   #   end
   #
@@ -101,7 +101,7 @@ module Rails
   #
   #   class MyRailtie < Rails::Railtie
   #     generators do
-  #       require 'path/to/my_railtie_generator'
+  #       require "path/to/my_railtie_generator"
   #     end
   #   end
   #
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index acfc1b71b7c..10881adeb36 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -116,7 +116,7 @@ module ApplicationTests
         end
       RUBY
       add_to_top_of_config <<-RUBY
-        require 'my_logger'
+        require "my_logger"
         config.logger = MyLogger.new STDOUT
       RUBY
 
diff --git a/railties/test/application/integration_test_case_test.rb b/railties/test/application/integration_test_case_test.rb
index c08761092bd..df981b0405d 100644
--- a/railties/test/application/integration_test_case_test.rb
+++ b/railties/test/application/integration_test_case_test.rb
@@ -19,7 +19,7 @@ module ApplicationTests
       rails "generate", "mailer", "BaseMailer", "welcome"
 
       app_file "test/integration/mailer_integration_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class MailerIntegrationTest < ActionDispatch::IntegrationTest
           setup do
@@ -59,7 +59,7 @@ module ApplicationTests
 
     test "app method of integration tests returns test_app by default" do
       app_file "test/integration/default_app_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class DefaultAppIntegrationTest < ActionDispatch::IntegrationTest
           def test_app_returns_action_dispatch_test_app_by_default
diff --git a/railties/test/application/rake/notes_test.rb b/railties/test/application/rake/notes_test.rb
index 47822e55b9b..d3566911497 100644
--- a/railties/test/application/rake/notes_test.rb
+++ b/railties/test/application/rake/notes_test.rb
@@ -108,7 +108,7 @@ module ApplicationTests
         app_file "test/some_test.rb", 1000.times.map { "" }.join("\n") << "# TODO: note in test directory"
 
         app_file "lib/tasks/notes_custom.rake", <<-EOS
-          require 'rails/source_annotation_extractor'
+          require "rails/source_annotation_extractor"
           task :notes_custom do
             tags = 'TODO|FIXME'
             opts = { dirs: %w(lib test), tag: true }
diff --git a/railties/test/application/server_test.rb b/railties/test/application/server_test.rb
index c7aec8d6017..1aa7003906c 100644
--- a/railties/test/application/server_test.rb
+++ b/railties/test/application/server_test.rb
@@ -23,7 +23,7 @@ module ApplicationTests
 
       File.open("#{app_path}/config/boot.rb", "w") do |f|
         f.puts "ENV['BUNDLE_GEMFILE'] = '#{Bundler.default_gemfile}'"
-        f.puts "require 'bundler/setup'"
+        f.puts 'require "bundler/setup"'
       end
 
       primary, replica = PTY.open
diff --git a/railties/test/application/test_runner_test.rb b/railties/test/application/test_runner_test.rb
index e53ba3a133a..34c9ea0c520 100644
--- a/railties/test/application/test_runner_test.rb
+++ b/railties/test/application/test_runner_test.rb
@@ -54,7 +54,7 @@ module ApplicationTests
 
     def test_run_file_with_syntax_error
       app_file "test/models/error_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
         def; end
       RUBY
 
@@ -188,7 +188,7 @@ module ApplicationTests
 
     def test_run_named_test
       app_file "test/unit/chu_2_koi_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class Chu2KoiTest < ActiveSupport::TestCase
           def test_rikka
@@ -209,7 +209,7 @@ module ApplicationTests
 
     def test_run_matched_test
       app_file "test/unit/chu_2_koi_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class Chu2KoiTest < ActiveSupport::TestCase
           def test_rikka
@@ -251,7 +251,7 @@ module ApplicationTests
     def test_run_different_environment_using_env_var
       skip "no longer possible. Running tests in a different environment should be explicit"
       app_file "test/unit/env_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class EnvTest < ActiveSupport::TestCase
           def test_env
@@ -322,7 +322,7 @@ module ApplicationTests
 
     def test_run_with_ruby_command
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           test 'declarative syntax works' do
@@ -343,7 +343,7 @@ module ApplicationTests
     def test_mix_files_and_line_filters
       create_test_file :models, "account"
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           def test_post
@@ -366,7 +366,7 @@ module ApplicationTests
 
     def test_more_than_one_line_filter
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           test "first filter" do
@@ -394,7 +394,7 @@ module ApplicationTests
 
     def test_more_than_one_line_filter_with_multiple_files
       app_file "test/models/account_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class AccountTest < ActiveSupport::TestCase
           test "first filter" do
@@ -414,7 +414,7 @@ module ApplicationTests
       RUBY
 
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           test "first filter" do
@@ -454,7 +454,7 @@ module ApplicationTests
 
     def test_line_filters_trigger_only_one_runnable
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           test 'truth' do
@@ -478,7 +478,7 @@ module ApplicationTests
 
     def test_line_filter_with_minitest_string_filter
       app_file "test/models/post_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostTest < ActiveSupport::TestCase
           test 'by line' do
@@ -527,7 +527,7 @@ module ApplicationTests
       app_file "config/boot.rb", <<-RUBY
         ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
-        require 'bundler/setup' # Set up gems listed in the Gemfile.
+        require "bundler/setup" # Set up gems listed in the Gemfile.
       RUBY
 
       assert_match "0 runs, 0 assertions", run_test_command("")
@@ -578,7 +578,7 @@ module ApplicationTests
       exercise_parallelization_regardless_of_machine_core_count(with: :processes)
 
       file_name = app_file("test/models/parallel_test.rb", <<-RUBY)
-        require 'test_helper'
+        require "test_helper"
 
         class ParallelTest < ActiveSupport::TestCase
           def test_crash
@@ -758,7 +758,7 @@ module ApplicationTests
 
     def test_warnings_option
       app_file "test/models/warnings_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
         def test_warnings
           a = 1
         end
@@ -920,7 +920,7 @@ module ApplicationTests
 
       def create_fixture_test(path = :unit, name = "test")
         app_file "test/#{path}/#{name}_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class #{name.camelize}Test < ActiveSupport::TestCase
             def test_fixture
@@ -932,7 +932,7 @@ module ApplicationTests
 
       def create_backtrace_test
         app_file "test/unit/backtrace_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class BacktraceTest < ActiveSupport::TestCase
             def test_backtrace
@@ -948,7 +948,7 @@ module ApplicationTests
 
       def create_test_for_env(env)
         app_file "test/models/environment_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
           class JSONReporter < Minitest::AbstractReporter
             def record(result)
               puts JSON.dump(klass: result.class.name,
@@ -972,7 +972,7 @@ module ApplicationTests
           # Minitest won't require the Rails minitest plugin when we run
           # these integration tests.  So we have to manually require the
           # Minitest plugin here.
-          require 'minitest/rails_plugin'
+          require "minitest/rails_plugin"
 
           class EnvironmentTest < ActiveSupport::TestCase
             def test_environment
@@ -987,7 +987,7 @@ module ApplicationTests
 
       def create_test_file(path = :unit, name = "test", pass: true, print: true)
         app_file "test/#{path}/#{name}_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class #{name.camelize}Test < ActiveSupport::TestCase
             def test_truth
@@ -1000,7 +1000,7 @@ module ApplicationTests
 
       def create_parallel_processes_test_file
         app_file "test/models/parallel_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class ParallelTest < ActiveSupport::TestCase
             RD1, WR1 = IO.pipe
@@ -1029,7 +1029,7 @@ module ApplicationTests
 
       def create_parallel_threads_test_file
         app_file "test/models/parallel_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class ParallelTest < ActiveSupport::TestCase
             Q1 = Queue.new
@@ -1059,7 +1059,7 @@ module ApplicationTests
 
       def create_env_test
         app_file "test/unit/env_test.rb", <<-RUBY
-          require 'test_helper'
+          require "test_helper"
 
           class EnvTest < ActiveSupport::TestCase
             def test_env
diff --git a/railties/test/application/test_test.rb b/railties/test/application/test_test.rb
index 17fc004c458..227a8cc6e86 100644
--- a/railties/test/application/test_test.rb
+++ b/railties/test/application/test_test.rb
@@ -21,7 +21,7 @@ module ApplicationTests
 
     test "simple successful test" do
       app_file "test/unit/foo_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class FooTest < ActiveSupport::TestCase
           def test_truth
@@ -35,7 +35,7 @@ module ApplicationTests
 
     test "after_run" do
       app_file "test/unit/foo_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         Minitest.after_run { puts "WORLD" }
         Minitest.after_run { puts "HELLO" }
@@ -53,7 +53,7 @@ module ApplicationTests
 
     test "simple failed test" do
       app_file "test/unit/foo_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class FooTest < ActiveSupport::TestCase
           def test_truth
@@ -76,7 +76,7 @@ module ApplicationTests
       HTML
 
       app_file "test/integration/posts_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class PostsTest < ActionDispatch::IntegrationTest
           def test_index
@@ -92,7 +92,7 @@ module ApplicationTests
 
     test "enable full backtraces on test failures" do
       app_file "test/unit/failing_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class FailingTest < ActiveSupport::TestCase
           def test_failure
@@ -111,7 +111,7 @@ module ApplicationTests
       version = output.match(/(\d+)_create_users\.rb/)[1]
 
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class UserTest < ActiveSupport::TestCase
           test "user" do
@@ -148,7 +148,7 @@ module ApplicationTests
       version = output.match(/(\d+)_create_users\.rb/)[1]
 
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class UserTest < ActiveSupport::TestCase
           test "user" do
@@ -187,7 +187,7 @@ module ApplicationTests
       version_1 = output_1.match(/(\d+)_create_users\.rb/)[1]
 
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
         class UserTest < ActiveSupport::TestCase
           test "user" do
             User.create! name: "Jon"
@@ -212,7 +212,7 @@ module ApplicationTests
       version_2 = output_2.match(/(\d+)_add_email_to_users\.rb/)[1]
 
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class UserTest < ActiveSupport::TestCase
           test "user" do
@@ -237,7 +237,7 @@ module ApplicationTests
       version = output.match(/(\d+)_create_users\.rb/)[1]
 
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
 
         class UserTest < ActiveSupport::TestCase
           test "user" do
@@ -291,7 +291,7 @@ Expected: ["id", "name"]
         end
       RUBY
       app_file "test/models/user_test.rb", <<-RUBY
-        require 'test_helper'
+        require "test_helper"
         class UserTest < ActiveSupport::TestCase
           test "user" do
             User.create! name: "Jon"
diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 193493d8692..636eb697beb 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -365,7 +365,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
       quietly { generator.send(:update_config_files) }
 
       assert_file "#{app_root}/config/boot.rb" do |content|
-        assert_no_match(/require 'bootsnap\/setup'/, content)
+        assert_no_match(/require "bootsnap\/setup"/, content)
       end
     end
   end
@@ -968,12 +968,12 @@ class AppGeneratorTest < Rails::Generators::TestCase
     unless defined?(JRUBY_VERSION)
       assert_gem "bootsnap"
       assert_file "config/boot.rb" do |content|
-        assert_match(/require 'bootsnap\/setup'/, content)
+        assert_match(/require "bootsnap\/setup"/, content)
       end
     else
       assert_no_gem "bootsnap"
       assert_file "config/boot.rb" do |content|
-        assert_no_match(/require 'bootsnap\/setup'/, content)
+        assert_no_match(/require "bootsnap\/setup"/, content)
       end
     end
   end
@@ -983,7 +983,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     assert_no_gem "bootsnap"
     assert_file "config/boot.rb" do |content|
-      assert_no_match(/require 'bootsnap\/setup'/, content)
+      assert_no_match(/require "bootsnap\/setup"/, content)
     end
   end
 
@@ -992,7 +992,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
 
     assert_no_gem "bootsnap"
     assert_file "config/boot.rb" do |content|
-      assert_no_match(/require 'bootsnap\/setup'/, content)
+      assert_no_match(/require "bootsnap\/setup"/, content)
     end
   end
 
diff --git a/railties/test/generators/generator_generator_test.rb b/railties/test/generators/generator_generator_test.rb
index eaa964cabc3..8f3022c85a2 100644
--- a/railties/test/generators/generator_generator_test.rb
+++ b/railties/test/generators/generator_generator_test.rb
@@ -20,7 +20,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
                 /class AwesomeGenerator < Rails::Generators::NamedBase/
     assert_file "test/lib/generators/awesome_generator_test.rb",
                /class AwesomeGeneratorTest < Rails::Generators::TestCase/,
-               /require 'generators\/awesome\/awesome_generator'/
+               /require "generators\/awesome\/awesome_generator"/
   end
 
   def test_namespaced_generator_skeleton
@@ -36,7 +36,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
                 /class Rails::AwesomeGenerator < Rails::Generators::NamedBase/
     assert_file "test/lib/generators/rails/awesome_generator_test.rb",
                /class Rails::AwesomeGeneratorTest < Rails::Generators::TestCase/,
-               /require 'generators\/rails\/awesome\/awesome_generator'/
+               /require "generators\/rails\/awesome\/awesome_generator"/
   end
 
   def test_generator_skeleton_is_created_without_file_name_namespace
@@ -52,7 +52,7 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
                 /class AwesomeGenerator < Rails::Generators::NamedBase/
     assert_file "test/lib/generators/awesome_generator_test.rb",
                /class AwesomeGeneratorTest < Rails::Generators::TestCase/,
-               /require 'generators\/awesome_generator'/
+               /require "generators\/awesome_generator"/
   end
 
   def test_namespaced_generator_skeleton_without_file_name_namespace
@@ -68,6 +68,6 @@ class GeneratorGeneratorTest < Rails::Generators::TestCase
                 /class Rails::AwesomeGenerator < Rails::Generators::NamedBase/
     assert_file "test/lib/generators/rails/awesome_generator_test.rb",
                /class Rails::AwesomeGeneratorTest < Rails::Generators::TestCase/,
-               /require 'generators\/rails\/awesome_generator'/
+               /require "generators\/rails\/awesome_generator"/
   end
 end
diff --git a/railties/test/generators/plugin_generator_test.rb b/railties/test/generators/plugin_generator_test.rb
index 2b62d0c8ec4..614937221ed 100644
--- a/railties/test/generators/plugin_generator_test.rb
+++ b/railties/test/generators/plugin_generator_test.rb
@@ -414,8 +414,8 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_file "bin/rails", /ENGINE_PATH = File\.expand_path\('\.\.\/lib\/bukkits\/engine', __dir__\)/
     assert_file "bin/rails", /ENGINE_ROOT = File\.expand_path\('\.\.', __dir__\)/
     assert_file "bin/rails", %r|APP_PATH = File\.expand_path\('\.\./test/dummy/config/application', __dir__\)|
-    assert_file "bin/rails", /require 'rails\/all'/
-    assert_file "bin/rails", /require 'rails\/engine\/commands'/
+    assert_file "bin/rails", /require "rails\/all"/
+    assert_file "bin/rails", /require "rails\/engine\/commands"/
   end
 
   def test_shebang
diff --git a/railties/test/generators/plugin_test_helper.rb b/railties/test/generators/plugin_test_helper.rb
index 528f8d88f9a..1357d042cbe 100644
--- a/railties/test/generators/plugin_test_helper.rb
+++ b/railties/test/generators/plugin_test_helper.rb
@@ -6,7 +6,7 @@ require "tmpdir"
 module PluginTestHelper
   def create_test_file(name, pass: true)
     plugin_file "test/#{name}_test.rb", <<-RUBY
-      require 'test_helper'
+      require "test_helper"
 
       class #{name.camelize}Test < ActiveSupport::TestCase
         def test_truth
diff --git a/railties/test/generators/plugin_test_runner_test.rb b/railties/test/generators/plugin_test_runner_test.rb
index 89c3f1e4966..a88e621cf15 100644
--- a/railties/test/generators/plugin_test_runner_test.rb
+++ b/railties/test/generators/plugin_test_runner_test.rb
@@ -30,7 +30,7 @@ class PluginTestRunnerTest < ActiveSupport::TestCase
   def test_mix_files_and_line_filters
     create_test_file "account"
     plugin_file "test/post_test.rb", <<-RUBY
-      require 'test_helper'
+      require "test_helper"
 
       class PostTest < ActiveSupport::TestCase
         def test_post
@@ -96,7 +96,7 @@ class PluginTestRunnerTest < ActiveSupport::TestCase
 
   def test_warnings_option
     plugin_file "test/models/warnings_test.rb", <<-RUBY
-      require 'test_helper'
+      require "test_helper"
       def test_warnings
         a = 1
       end
diff --git a/railties/test/isolation/abstract_unit.rb b/railties/test/isolation/abstract_unit.rb
index 8aa2f306238..8513f3690d2 100644
--- a/railties/test/isolation/abstract_unit.rb
+++ b/railties/test/isolation/abstract_unit.rb
@@ -513,7 +513,7 @@ Module.new do
 
   sh "#{Gem.ruby} #{RAILS_FRAMEWORK_ROOT}/railties/exe/rails new #{app_template_path} --skip-bundle --skip-listen --no-rc --skip-webpack-install --quiet"
   File.open("#{app_template_path}/config/boot.rb", "w") do |f|
-    f.puts "require 'rails/all'"
+    f.puts 'require "rails/all"'
   end
 
   unless File.exist?("#{RAILS_FRAMEWORK_ROOT}/actionview/lib/assets/compiled/rails-ujs.js")
diff --git a/railties/test/railties/engine_test.rb b/railties/test/railties/engine_test.rb
index 051dc7d5abc..9c7fac70803 100644
--- a/railties/test/railties/engine_test.rb
+++ b/railties/test/railties/engine_test.rb
@@ -52,7 +52,7 @@ module RailtiesTest
 
       @plugin.write "Rakefile", <<-RUBY
         APP_RAKEFILE = '#{app_path}/Rakefile'
-        load 'rails/tasks/engine.rake'
+        load "rails/tasks/engine.rake"
         task :foo => :environment do
           puts "Task ran"
         end
@@ -200,7 +200,7 @@ module RailtiesTest
 
       @plugin.write "Rakefile", <<-RUBY
         APP_RAKEFILE = '#{app_path}/Rakefile'
-        load 'rails/tasks/engine.rake'
+        load "rails/tasks/engine.rake"
       RUBY
 
       add_to_config "ActiveRecord::Base.timestamped_migrations = false"
@@ -1532,7 +1532,7 @@ en:
     test "active_storage:install task works within engine" do
       @plugin.write "Rakefile", <<-RUBY
         APP_RAKEFILE = '#{app_path}/Rakefile'
-        load 'rails/tasks/engine.rake'
+        load "rails/tasks/engine.rake"
       RUBY
 
       Dir.chdir(@plugin.path) do
@@ -1555,8 +1555,8 @@ en:
 
     # Restrict frameworks to load in order to avoid engine frameworks affect tests.
     def restrict_frameworks
-      remove_from_config("require 'rails/all'")
-      remove_from_config("require_relative 'boot'")
+      remove_from_config('require "rails/all"')
+      remove_from_config('require_relative "boot"')
       remove_from_env_config("development", "config.active_storage.*")
       frameworks = <<~RUBY
         require "rails"