Add frozen string literal comments

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ruby '2.5.1'
 
 source 'https://rubygems.org'

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'config/application'
 
 Rails.application.load_tasks

app/channels/application_cable/channel.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Channel < ActionCable::Channel::Base
   end

app/channels/application_cable/connection.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Connection < ActionCable::Connection::Base
   end

app/controllers/application_controller.rb

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
 end

app/helpers/application_helper.rb

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
 end

app/jobs/application_job.rb

@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ApplicationJob < ActiveJob::Base
 end

app/mailers/application_mailer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationMailer < ActionMailer::Base
   default from: 'from@example.com'
   layout 'mailer'

app/models/application_record.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationRecord < ActiveRecord::Base
   self.abstract_class = true
 end

config.ru

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
 require_relative 'config/environment'

config/application.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'boot'
 
 require "rails"

config/boot.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.

config/environment.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Load the Rails application.
 require_relative 'application'
 

config/environments/development.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 

config/environments/production.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 

config/environments/test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 

config/initializers/application_controller_renderer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # ActiveSupport::Reloader.to_prepare do

config/initializers/assets.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Version of your assets, change this if you want to expire all your assets.

config/initializers/backtrace_silencers.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # You can add backtrace silencers for libraries that you're using but don't wish to see in your backtraces.

config/initializers/content_security_policy.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Define an application-wide content security policy

config/initializers/cookies_serializer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Specify a serializer for the signed and encrypted cookie jars.

config/initializers/filter_parameter_logging.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Configure sensitive parameters which will be filtered from the log file.

config/initializers/inflections.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Add new inflection rules using the following format. Inflections

config/initializers/mime_types.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Add new mime types for use in respond_to blocks:

config/initializers/wrap_parameters.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # This file contains settings for ActionController::ParamsWrapper which

config/puma.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Puma can serve each request in a thread from an internal thread pool.
 # The `threads` method setting takes two numbers: a minimum and maximum.
 # Any libraries that use thread pools should be configured to match

config/routes.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.routes.draw do
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end

config/spring.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 %w[
   .ruby-version
   .rbenv-vars