cops: enable frozen_string_literal

.rubocop.yml

@@ -16,6 +16,9 @@ AllCops:
 Standard/SemanticBlocks:
   Enabled: false
 
+Style/FrozenStringLiteralComment:
+  Enabled: true
+
 Style/TrailingCommaInArrayLiteral:
   EnforcedStyleForMultiline: no_comma
 

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
 require "rubocop/rake_task"

gemfiles/rails42.gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 gem "activesupport", "~> 4.2"

gemfiles/railsmaster.gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 gem "rails", github: "rails/rails"

lib/active_delivery.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_delivery/version"
 require "active_delivery/base"
 require "active_delivery/callbacks" if defined?(ActiveSupport)

lib/active_delivery/lines/base.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveDelivery
   module Lines
     class Base

lib/active_delivery/lines/mailer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveDelivery
   module Lines
     class Mailer < Base

lib/active_delivery/testing.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveDelivery
   module TestDelivery
     class << self

lib/active_delivery/testing/rspec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveDelivery
   class HaveDeliveredTo < RSpec::Matchers::BuiltIn::BaseMatcher
     attr_reader :delivery_class, :event, :args, :params, :sync_value

lib/active_delivery/version.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ActiveDelivery
   VERSION = "0.1.1"
 end

spec/spec_helper.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 ENV["RACK_ENV"] = "test"
 
 require "bundler/setup"

spec/support/quack.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Quack
   attr_reader :mid