Enforce Style/FrozenStringLiteralComment.

The frozen_string_literal: true magic comment in Ruby can help
dramatically decrease memory allocations for new strings and can thusly
speed up your program. The intent here is for Jekyll to use less memory
and make fewer memory allocations (which must later be GC'd).

.rubocop.yml

@@ -99,6 +99,9 @@ Style/BracesAroundHashParameters:
   Enabled: false
 Style/ClassAndModuleChildren:
   Enabled: false
+Style/FrozenStringLiteralComment:
+  Enabled: true
+  EnforcedStyle: always
 Style/Documentation:
   Enabled: false
   Exclude:

Gemfile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 gemspec :name => "jekyll"
 

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "rubygems"
 require "rake"
 require "rdoc"

docs/_docs/history.md

@@ -27,7 +27,7 @@ note: This file is autogenerated. Edit /History.markdown instead.
 - add plugins for multiple page pagination ([#6055]({{ site.repository }}/issues/6055))
 - Update minimum Ruby version in installation.md ([#6164]({{ site.repository }}/issues/6164))
 - [docs] Add information about finding a collection in `site.collections` ([#6165]({{ site.repository }}/issues/6165))
-- Add {%raw%} to Liquid example on site ([#6179]({{ site.repository }}/issues/6179))
+- Add {% raw %}`{% raw %}`{% endraw %} to Liquid example on site ([#6179]({{ site.repository }}/issues/6179))
 - Added improved Pug plugin - removed 404 Jade plugin ([#6174]({{ site.repository }}/issues/6174))
 - Linking the link ([#6210]({{ site.repository }}/issues/6210))
 - Small correction in documentation for includes ([#6193]({{ site.repository }}/issues/6193))

features/step_definitions.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Before do
   FileUtils.rm_rf(Paths.test_dir) if Paths.test_dir.exist?
   FileUtils.mkdir_p(Paths.test_dir) unless Paths.test_dir.directory?

features/support/formatter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "fileutils"
 require "colorator"
 require "cucumber/formatter/console"

features/support/helpers.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "fileutils"
 require "jekyll"
 require "time"
@@ -107,7 +109,7 @@ def run_in_shell(*args)
 
   File.write(Paths.status_file, p.exitstatus)
   File.open(Paths.output_file, "wb") do |f|
-    f.puts "$ " << args.join(" ")
+    f.puts "$ #{args.join(" ")}"
     f.puts output
     f.puts "EXIT STATUS: #{p.exitstatus}"
   end

jekyll.gemspec

@@ -1,4 +1,5 @@
 # coding: utf-8
+# frozen_string_literal: true
 
 lib = File.expand_path("lib", __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)

lib/jekyll.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.unshift __dir__ # For use/testing when no gem is installed
 
 # Require all of the Ruby files in the given directory.
@@ -162,8 +164,9 @@ def sites
     def sanitized_path(base_directory, questionable_path)
       return base_directory if base_directory.eql?(questionable_path)
 
-      questionable_path.insert(0, "/") if questionable_path.start_with?("~")
-      clean_path = File.expand_path(questionable_path, "/")
+      clean_path = questionable_path.dup
+      clean_path.insert(0, "/") if clean_path.start_with?("~")
+      clean_path = File.expand_path(clean_path, "/")
 
       return clean_path if clean_path.eql?(base_directory)
 

lib/jekyll/cleaner.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "set"
 
 module Jekyll

lib/jekyll/collection.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class Collection
     attr_reader :site, :label, :metadata

lib/jekyll/command.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class Command
     class << self

lib/jekyll/commands/build.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Commands
     class Build < Command

lib/jekyll/commands/clean.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Commands
     class Clean < Command

lib/jekyll/commands/doctor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "addressable/uri"
 
 module Jekyll

lib/jekyll/commands/help.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Commands
     class Help < Command

lib/jekyll/commands/new.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "erb"
 
 module Jekyll

lib/jekyll/commands/new_theme.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "erb"
 
 class Jekyll::Commands::NewTheme < Jekyll::Command

lib/jekyll/commands/serve.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Commands
     class Serve < Command

lib/jekyll/commands/serve/servlet.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "webrick"
 
 module Jekyll

lib/jekyll/configuration.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   class Configuration < Hash

lib/jekyll/converter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class Converter < Plugin
     # Public: Get or set the highlighter prefix. When an argument is specified,

lib/jekyll/converters/identity.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Converters
     class Identity < Converter

lib/jekyll/converters/markdown.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Converters
     class Markdown < Converter

lib/jekyll/converters/markdown/rdiscount_parser.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Converters
     class Markdown

lib/jekyll/converters/markdown/redcarpet_parser.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Jekyll::Converters::Markdown::RedcarpetParser
   module CommonMethods
     def add_code_tags(code, lang)
@@ -48,9 +50,7 @@ module WithRouge
     def block_code(code, lang)
       code = "<pre>#{super}</pre>"
 
-      output = "<div class=\"highlight\">"
-      output << add_code_tags(code, lang)
-      output << "</div>"
+      "<div class=\"highlight\">#{add_code_tags(code, lang)}</div>"
     end
 
     protected

lib/jekyll/converters/smartypants.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Kramdown::Parser::SmartyPants < Kramdown::Parser::Kramdown
   def initialize(source, options)
     super

lib/jekyll/convertible.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 require "set"
 

lib/jekyll/deprecator.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Deprecator
     extend self

lib/jekyll/document.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   class Document

lib/jekyll/drops/collection_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/document_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/excerpt_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/jekyll_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/site_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/static_file_drop.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Drops
     class StaticFileDrop < Drop

lib/jekyll/drops/unified_payload_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/drops/url_drop.rb

@@ -1,4 +1,5 @@
 # encoding: UTF-8
+# frozen_string_literal: true
 
 module Jekyll
   module Drops

lib/jekyll/entry_filter.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class EntryFilter
     attr_reader :site

lib/jekyll/errors.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Errors
     FatalException = Class.new(::RuntimeError)

lib/jekyll/excerpt.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class Excerpt
     extend Forwardable
@@ -117,7 +119,7 @@ def extract_excerpt(doc_content)
       if tail.empty?
         head
       else
-        "" << head << "\n\n" << tail.scan(%r!^ {0,3}\[[^\]]+\]:.+$!).join("\n")
+        head.to_s.dup << "\n\n" << tail.scan(%r!^ {0,3}\[[^\]]+\]:.+$!).join("\n")
       end
     end
   end

lib/jekyll/external.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module External
     class << self

lib/jekyll/filters.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "addressable/uri"
 require "json"
 require "date"

lib/jekyll/filters/grouping_filters.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Filters
     module GroupingFilters

lib/jekyll/filters/url_filters.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "addressable/uri"
 
 module Jekyll

lib/jekyll/frontmatter_defaults.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   # This class handles custom defaults for YAML frontmatter settings.
   # These are set in _config.yml and apply both to internal use (e.g. layout)

lib/jekyll/generator.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   Generator = Class.new(Plugin)
 end

lib/jekyll/hooks.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module Hooks
     DEFAULT_PRIORITY = 20

lib/jekyll/layout.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class Layout
     include Convertible

lib/jekyll/liquid_extensions.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   module LiquidExtensions
 

lib/jekyll/liquid_renderer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "jekyll/liquid_renderer/file"
 require "jekyll/liquid_renderer/table"
 

lib/jekyll/liquid_renderer/file.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class LiquidRenderer
     class File

lib/jekyll/liquid_renderer/table.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Jekyll
   class LiquidRenderer::Table
     def initialize(stats)
@@ -13,7 +15,7 @@ def to_s(n = 50)
     private
 
     def generate_table(data, widths)
-      str = "\n"
+      str = String.new("\n")
 
       table_head = data.shift
       str << generate_row(table_head, widths)
@@ -28,7 +30,7 @@ def generate_table(data, widths)
     end
 
     def generate_table_head_border(row_data, widths)
-      str = ""
+      str = String.new("")
 
       row_data.each_index do |cell_index|
         str << "-" * widths[cell_index]
@@ -40,7 +42,7 @@ def generate_table_head_border(row_data, widths)
     end
 
     def generate_row(row_data, widths)
-      str = ""
+      str = String.new("")
 
       row_data.each_with_index do |cell_data, cell_index|
         str << if cell_index.zero?