Enable frozen_string_literal

Closes #264

Gemfile

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 source "https://rubygems.org"
 
-gemspec
+gemspec

Rakefile

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 begin
   require 'bundler/gem_tasks'
 rescue LoadError

lib/slop.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'slop/option'
 require 'slop/options'
 require 'slop/parser'

lib/slop/error.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   # Base error class.
   class Error < StandardError

lib/slop/option.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   class Option
     DEFAULT_CONFIG = {

lib/slop/options.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   class Options
     include Enumerable

lib/slop/parser.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   class Parser
 

lib/slop/result.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   # This class encapsulates a Parser and Options pair. The idea is that
   # the Options class shouldn't have to deal with what happens when options

lib/slop/types.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 module Slop
   # Cast the option argument to a String.
   class StringOption < Option

test/error_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 
 # All raised errors tested here

test/option_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 
 describe Slop::Option do

test/options_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 
 describe Slop::Options do

test/parser_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 require 'shellwords'
 

test/result_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 
 module Slop

test/slop_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require "test_helper"
 
 describe Slop do

test/test_helper.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 $VERBOSE = true
 
 require 'slop'

test/types_test.rb

@@ -1,3 +1,5 @@
+# frozen-string-literal: true
+
 require 'test_helper'
 
 describe Slop::StringOption do