(FACT-3428) Style/FrozenStringLiteralComment

Add missing frozen string literal. In cases where we have a frozen string
literal and want to mutate it, then use the unary plus, which "thaws" a
frozen string, such as `+''`

In cases where we're passed a frozen string from somewhere else, call String.dup
to create a mutable copy.

In both cases, the original string encoding is preserved:

    irb(main):007> str = ''.encode('UTF-16LE')
    => ""
    irb(main):008> str.dup.encoding
    => #<Encoding:UTF-16LE>
    irb(main):009> (+str).encoding
    => #<Encoding:UTF-16LE>

Unlike String.new

    irb(main):010> String.new.encoding
    => #<Encoding:ASCII-8BIT>

Author: joshcooper

.rubocop_todo.yml

@@ -205,19 +205,6 @@ Style/FormatStringToken:
     - 'lib/facter/resolvers/amzn/os_release_rpm.rb'
     - 'spec/facter/resolvers/amzn/os_release_rpm_spec.rb'
 
-# Offense count: 6
-# This cop supports unsafe autocorrection (--autocorrect-all).
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: always, always_true, never
-Style/FrozenStringLiteralComment:
-  Exclude:
-    - 'lib/facter/custom_facts/core/execution/posix.rb'
-    - 'lib/facter/custom_facts/core/execution/windows.rb'
-    - 'lib/facter/custom_facts/util/resolution.rb'
-    - 'spec/custom_facts/core/execution/posix_spec.rb'
-    - 'spec/custom_facts/core/execution/windows_spec.rb'
-    - 'spec/custom_facts/util/normalization_spec.rb'
-
 # Offense count: 5
 # This cop supports unsafe autocorrection (--autocorrect-all).
 Style/GlobalStdStream:

lib/facter/custom_facts/core/execution/posix.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Facter
   module Core
     module Execution
@@ -44,7 +46,8 @@ def expand_command(command)
 
           return unless exe && (expanded = which(exe))
 
-          expanded = "'#{expanded}'" if /\s/.match?(expanded)
+          expanded = expanded.dup
+          expanded = +"'#{expanded}'" if /\s/.match?(expanded)
           expanded << " #{args}" if args
 
           expanded

lib/facter/custom_facts/core/execution/windows.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Facter
   module Core
     module Execution
@@ -56,7 +58,8 @@ def expand_command(command)
 
           return unless exe && (expanded = which(exe))
 
-          expanded = "\"#{expanded}\"" if /\s+/.match?(expanded)
+          expanded = expanded.dup
+          expanded = +"\"#{expanded}\"" if /\s+/.match?(expanded)
           expanded << " #{args}" if args
 
           expanded

lib/facter/custom_facts/util/resolution.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This represents a fact resolution. A resolution is a concrete
 # implementation of a fact. A single fact can have many resolutions and
 # the correct resolution will be chosen at runtime. Each time
@@ -88,7 +90,7 @@ def resolution_type
       # @api private
       def evaluate(&block)
         if @last_evaluated
-          msg = "Already evaluated #{@name}"
+          msg = +"Already evaluated #{@name}"
           msg << " at #{@last_evaluated}" if msg.is_a? String
           msg << ', reevaluating anyways'
           log.warn msg

spec/custom_facts/core/execution/posix_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Facter::Core::Execution::Posix, unless: LegacyFacter::Util::Config.windows? do
   let(:posix_executor) { Facter::Core::Execution::Posix.new }
 

spec/custom_facts/core/execution/windows_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Facter::Core::Execution::Windows do
   let(:executor) { Facter::Core::Execution::Windows.new }
 

spec/custom_facts/util/normalization_spec.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe LegacyFacter::Util::Normalization do
   subject(:normalization) { LegacyFacter::Util::Normalization }
 
@@ -44,15 +46,15 @@ def utf8(str)
       end
 
       it 'rejects strings that are not UTF-8 and do not match their claimed encoding' do
-        invalid_shift_jis = "\xFF\x5C!".force_encoding(Encoding::SHIFT_JIS)
+        invalid_shift_jis = (+"\xFF\x5C!").force_encoding(Encoding::SHIFT_JIS)
         expect do
           normalization.normalize(invalid_shift_jis)
         end.to raise_error(LegacyFacter::Util::Normalization::NormalizationError,
                            /String encoding Shift_JIS is not UTF-8 and could not be converted to UTF-8/)
       end
 
       it "rejects strings that claim to be UTF-8 encoded but aren't" do
-        str = "\255ay!".force_encoding(Encoding::UTF_8)
+        str = (+"\255ay!").force_encoding(Encoding::UTF_8)
         expect do
           normalization.normalize(str)
         end.to raise_error(LegacyFacter::Util::Normalization::NormalizationError,