Merge pull request #81 from halostatue/switch-to-standardrb-formattingHEADmain

Switch to standardrb formatting

29 files changed, 937 insertions, 887 deletions

diff --git a/.fasterer.yml b/.fasterer.yml
index 821e02d..eef484f 100644
--- a/.fasterer.yml
+++ b/.fasterer.yml
@@ -1,4 +1,3 @@
 exclude_paths:
-  - lib/diff/lcs.rb # sort_vs_sort_by on priority_compare
-  - Rakefile # each_with_index vs while
-  - spec/spec_helper.rb
+  - research/**/*
+  - pkg/**/*
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 2fe2010..a1548a1 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -9,14 +9,14 @@
 # the `language` matrix defined below to confirm you have the correct set of
 # supported CodeQL languages.
 #
-name: "CodeQL"
+name: 'CodeQL'
 
 on:
   push:
-    branches: [ master, main ]
+    branches: [main]
   pull_request:
     # The branches below must be a subset of the branches above
-    branches: [ master, main ]
+    branches: [main]
   schedule:
     - cron: '28 4 * * 2'
 
@@ -32,39 +32,39 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        language: [ 'ruby' ]
+        language: ['ruby']
         # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
         # Learn more about CodeQL language support at https://git.io/codeql-language-support
 
     steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2
+      - name: Checkout repository
+        uses: actions/checkout@v2
 
-    # Initializes the CodeQL tools for scanning.
-    - name: Initialize CodeQL
-      uses: github/codeql-action/init@v1
-      with:
-        languages: ${{ matrix.language }}
-        # If you wish to specify custom queries, you can do so here or in a config file.
-        # By default, queries listed here will override any specified in a config file.
-        # Prefix the list here with "+" to use these queries and those in the config file.
-        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v1
+        with:
+          languages: ${{ matrix.language }}
+          # If you wish to specify custom queries, you can do so here or in a config file.
+          # By default, queries listed here will override any specified in a config file.
+          # Prefix the list here with "+" to use these queries and those in the config file.
+          # queries: ./path/to/local/query, your-org/your-repo/queries@main
 
-    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
-    # If this step fails, then you should remove it and run the build manually (see below)
-    - name: Autobuild
-      uses: github/codeql-action/autobuild@v1
+      # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+      # If this step fails, then you should remove it and run the build manually (see below)
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v1
 
-    # ℹ️ Command-line programs to run using the OS shell.
-    # 📚 https://git.io/JvXDl
+      # ℹ️ Command-line programs to run using the OS shell.
+      # 📚 https://git.io/JvXDl
 
-    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
-    #    and modify them (or add more) to build your code if your project
-    #    uses a compiled language
+      # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+      #    and modify them (or add more) to build your code if your project
+      #    uses a compiled language
 
-    #- run: |
-    #   make bootstrap
-    #   make release
+      #- run: |
+      #   make bootstrap
+      #   make release
 
-    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v1
diff --git a/.standard.yml b/.standard.yml
new file mode 100644
index 0000000..227fe7b
--- /dev/null
+++ b/.standard.yml
@@ -0,0 +1,6 @@
+parallel: true
+ruby_version: 2.0
+ignore:
+  - 'diff-lcs.gemspec'
+  - 'research/**/*'
+  - 'pkg/**/*'
diff --git a/Gemfile b/Gemfile
index 7b9f817..2840096 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,19 +3,23 @@
 # NOTE: This file is present to keep Travis CI happy. Edits to it will not
 # be accepted.
 
-source 'https://rubygems.org/'
+source "https://rubygems.org/"
 
-if RUBY_VERSION < '1.9'
-  gem 'hoe', '~> 3.20'
-  gem 'rake', '< 11'
-  gem 'rdoc', '< 4'
+if RUBY_VERSION < "1.9"
+  gem "hoe", "~> 3.20"
+  gem "rake", "< 11"
+  gem "rdoc", "< 4"
 
-  gem 'ruby-debug'
-elsif RUBY_VERSION >= '2.0'
-  if RUBY_ENGINE == 'ruby'
-    gem 'simplecov', '~> 0.18'
+  gem "ruby-debug"
+end
+
+if RUBY_VERSION >= "2.0"
+  gem "standardrb"
+  gem "fasterer"
 
-    gem 'byebug'
+  if RUBY_ENGINE == "ruby"
+    gem "simplecov", "~> 0.18"
+    gem "byebug"
   end
 end
 
diff --git a/History.md b/History.md
index a168d7e..a108b9f 100644
--- a/History.md
+++ b/History.md
@@ -4,6 +4,8 @@
 
 - Updated the CI configuration, resolving [#82][].
 
+- Switched to standard ruby formatting.
+
 ## 1.5.0 / 2021-12-23
 
 - Updated the CI configuration and monkey-patch Hoe.
diff --git a/Rakefile b/Rakefile
index fd7ee31..8179e81 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require 'rubygems'
-require 'rspec'
-require 'rspec/core/rake_task'
-require 'hoe'
+require "rubygems"
+require "rspec"
+require "rspec/core/rake_task"
+require "hoe"
 
 # This is required until https://github.com/seattlerb/hoe/issues/112 is fixed
 class Hoe
@@ -45,66 +45,71 @@ Hoe.plugin :doofus
 Hoe.plugin :gemspec2
 Hoe.plugin :git
 
-if RUBY_VERSION < '1.9'
-  class Array #:nodoc:
+if RUBY_VERSION < "1.9"
+  class Array # :nodoc:
     def to_h
       Hash[*flatten(1)]
     end
   end
 
-  class Gem::Specification #:nodoc:
-    def metadata=(*); end
+  class Gem::Specification # :nodoc:
+    def metadata=(*)
+    end
 
-    def default_value(*); end
+    def default_value(*)
+    end
   end
 
-  class Object #:nodoc:
+  class Object # :nodoc:
     def caller_locations(*)
       []
     end
   end
 end
 
-_spec = Hoe.spec 'diff-lcs' do
-  developer('Austin Ziegler', 'halostatue@gmail.com')
+_spec = Hoe.spec "diff-lcs" do
+  developer("Austin Ziegler", "halostatue@gmail.com")
 
-  require_ruby_version '>= 1.8'
+  require_ruby_version ">= 1.8"
 
-  self.history_file = 'History.md'
-  self.readme_file = 'README.rdoc'
-  self.licenses = ['MIT', 'Artistic-2.0', 'GPL-2.0+']
+  self.history_file = "History.md"
+  self.readme_file = "README.rdoc"
+  self.licenses = ["MIT", "Artistic-2.0", "GPL-2.0+"]
 
-  extra_dev_deps << ['hoe-doofus', '~> 1.0']
-  extra_dev_deps << ['hoe-gemspec2', '~> 1.1']
-  extra_dev_deps << ['hoe-git', '~> 1.6']
-  extra_dev_deps << ['hoe-rubygems', '~> 1.0']
-  extra_dev_deps << ['rspec', '>= 2.0', '< 4']
-  extra_dev_deps << ['rake', '>= 10.0', '< 14']
-  extra_dev_deps << ['rdoc', '>= 6.3.1', '< 7']
+  extra_dev_deps << ["hoe-doofus", "~> 1.0"]
+  extra_dev_deps << ["hoe-gemspec2", "~> 1.1"]
+  extra_dev_deps << ["hoe-git", "~> 1.6"]
+  extra_dev_deps << ["hoe-rubygems", "~> 1.0"]
+  extra_dev_deps << ["rspec", ">= 2.0", "< 4"]
+  extra_dev_deps << ["rake", ">= 10.0", "< 14"]
+  extra_dev_deps << ["rdoc", ">= 6.3.1", "< 7"]
 end
 
 desc "Run all specifications"
 RSpec::Core::RakeTask.new(:spec) do |t|
-  rspec_dirs = %w(spec lib).join(":")
+  rspec_dirs = %w[spec lib].join(":")
   t.rspec_opts = ["-I#{rspec_dirs}"]
 end
 
 Rake::Task["spec"].actions.uniq! { |a| a.source_location }
 
+# standard:disable Style/HashSyntax
 task :default => :spec unless Rake::Task["default"].prereqs.include?("spec")
 task :test => :spec unless Rake::Task["test"].prereqs.include?("spec")
+# standard:enable Style/HashSyntax
 
-if RUBY_VERSION >= '2.0' && RUBY_ENGINE == 'ruby'
+if RUBY_VERSION >= "2.0" && RUBY_ENGINE == "ruby"
   namespace :spec do
     desc "Runs test coverage. Only works Ruby 2.0+ and assumes 'simplecov' is installed."
     task :coverage do
-      ENV['COVERAGE'] = 'yes'
-      Rake::Task['spec'].execute
+      ENV["COVERAGE"] = "yes"
+      Rake::Task["spec"].execute
     end
   end
 end
 
 task :ruby18 do
+  # standard:disable Layout/HeredocIndentation
   puts <<-MESSAGE
 You are starting a barebones Ruby 1.8 docker environment. You will need to
 do the following:
@@ -117,5 +122,6 @@ do the following:
 Don't forget to restore your Gemfile.lock after testing.
 
   MESSAGE
+  # standard:enable Layout/HeredocIndentation
   sh "docker run -it --rm -v #{Dir.pwd}:/root/diff-lcs bellbind/docker-ruby18-rails2 bash -l"
 end
diff --git a/bin/htmldiff b/bin/htmldiff
index 14114a7..bcd89d2 100755
--- a/bin/htmldiff
+++ b/bin/htmldiff
@@ -1,11 +1,11 @@
 #! /usr/bin/env ruby -w
 # frozen_string_literal: true
 
-require 'diff/lcs'
-require 'diff/lcs/htmldiff'
+require "diff/lcs"
+require "diff/lcs/htmldiff"
 
 begin
-  require 'text/format'
+  require "text/format"
 rescue LoadError
   Diff::LCS::HTMLDiff.can_expand_tabs = false
 end
@@ -24,7 +24,7 @@ options = { :title => "diff #{ARGV[0]} #{ARGV[1]}" }
 htmldiff = Diff::LCS::HTMLDiff.new(left, right, options)
 
 if ARGV[2]
-  File.open(ARGV[2], 'w') do |f|
+  File.open(ARGV[2], "w") do |f|
     htmldiff.options[:output] = f
     htmldiff.run
   end
diff --git a/lib/diff-lcs.rb b/lib/diff-lcs.rb
index 250392f..bc07bf9 100644
--- a/lib/diff-lcs.rb
+++ b/lib/diff-lcs.rb
@@ -1,3 +1,3 @@
 # frozen_string_literal: true
 
-require 'diff/lcs'
+require "diff/lcs"
diff --git a/lib/diff/lcs.rb b/lib/diff/lcs.rb
index 288cfc2..54ef893 100644
--- a/lib/diff/lcs.rb
+++ b/lib/diff/lcs.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-module Diff; end unless defined? Diff # rubocop:disable Style/Documentation
+module Diff; end unless defined? Diff
 
 # == How Diff Works (by Mark-Jason Dominus)
 #
@@ -49,13 +49,13 @@ module Diff; end unless defined? Diff # rubocop:disable Style/Documentation
 #          a x b y c z p d q
 #    a b c a x b y c z
 module Diff::LCS
-  VERSION = '1.5.0'
+  VERSION = "1.5.0"
 end
 
-require 'diff/lcs/callbacks'
-require 'diff/lcs/internals'
+require "diff/lcs/callbacks"
+require "diff/lcs/internals"
 
-module Diff::LCS # rubocop:disable Style/Documentation
+module Diff::LCS
   # Returns an Array containing the longest common subsequence(s) between
   # +self+ and +other+. See Diff::LCS#lcs.
   #
@@ -67,7 +67,7 @@ module Diff::LCS # rubocop:disable Style/Documentation
   # identically for key purposes. That is:
   #
   #   O.new('a').eql?(O.new('a')) == true
-  def lcs(other, &block) #:yields self[i] if there are matched subsequences:
+  def lcs(other, &block) # :yields: self[i] if there are matched subsequences
     Diff::LCS.lcs(self, other, &block)
   end
 
@@ -101,7 +101,7 @@ module Diff::LCS # rubocop:disable Style/Documentation
   def patch(patchset)
     Diff::LCS.patch(self, patchset)
   end
-  alias unpatch patch
+  alias_method :unpatch, :patch
 
   # Attempts to patch +self+ with the provided +patchset+. A new sequence based
   # on +self+ and the +patchset+ will be created. See Diff::LCS#patch. Does no
@@ -141,11 +141,11 @@ module Diff::LCS # rubocop:disable Style/Documentation
 end
 
 class << Diff::LCS
-  def lcs(seq1, seq2, &block) #:yields seq1[i] for each matched:
+  def lcs(seq1, seq2, &block) # :yields: seq1[i] for each matched
     matches = Diff::LCS::Internals.lcs(seq1, seq2)
     ret = []
-    string = seq1.kind_of? String
-    matches.each_with_index do |_e, i|
+    string = seq1.is_a? String
+    matches.each_index do |i|
       next if matches[i].nil?
 
       v = string ? seq1[i, 1] : seq1[i]
@@ -154,7 +154,7 @@ class << Diff::LCS
     end
     ret
   end
-  alias LCS lcs
+  alias_method :LCS, :lcs
 
   # #diff computes the smallest set of additions and deletions necessary to
   # turn the first sequence into the second, and returns a description of these
@@ -165,7 +165,7 @@ class << Diff::LCS
   # Class argument is provided for +callbacks+, #diff will attempt to
   # initialise it. If the +callbacks+ object (possibly initialised) responds to
   # #finish, it will be called.
-  def diff(seq1, seq2, callbacks = nil, &block) # :yields diff changes:
+  def diff(seq1, seq2, callbacks = nil, &block) # :yields: diff changes
     diff_traversal(:diff, seq1, seq2, callbacks || Diff::LCS::DiffCallbacks, &block)
   end
 
@@ -197,7 +197,7 @@ class << Diff::LCS
   #       # insert
   #     end
   #   end
-  def sdiff(seq1, seq2, callbacks = nil, &block) #:yields diff changes:
+  def sdiff(seq1, seq2, callbacks = nil, &block) # :yields: diff changes
     diff_traversal(:sdiff, seq1, seq2, callbacks || Diff::LCS::SDiffCallbacks, &block)
   end
 
@@ -282,12 +282,12 @@ class << Diff::LCS
   # <tt>callbacks#discard_b</tt> will be called after the end of the sequence
   # is reached, if +a+ has not yet reached the end of +A+ or +b+ has not yet
   # reached the end of +B+.
-  def traverse_sequences(seq1, seq2, callbacks = Diff::LCS::SequenceCallbacks) #:yields change events:
+  def traverse_sequences(seq1, seq2, callbacks = Diff::LCS::SequenceCallbacks) # :yields: change events
     callbacks ||= Diff::LCS::SequenceCallbacks
     matches = Diff::LCS::Internals.lcs(seq1, seq2)
 
     run_finished_a = run_finished_b = false
-    string = seq1.kind_of?(String)
+    string = seq1.is_a?(String)
 
     a_size = seq1.size
     b_size = seq2.size
@@ -299,7 +299,7 @@ class << Diff::LCS
           ax = string ? seq1[ai, 1] : seq1[ai]
           bx = string ? seq2[bj, 1] : seq2[bj]
 
-          event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_a(event)
         end
@@ -310,13 +310,13 @@ class << Diff::LCS
           break unless bj < b_line
 
           bx = string ? seq2[bj, 1] : seq2[bj]
-          event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_b(event)
           bj += 1
         end
         bx = string ? seq2[bj, 1] : seq2[bj]
-        event = Diff::LCS::ContextChange.new('=', ai, ax, bj, bx)
+        event = Diff::LCS::ContextChange.new("=", ai, ax, bj, bx)
         event = yield event if block_given?
         callbacks.match(event)
         bj += 1
@@ -326,13 +326,13 @@ class << Diff::LCS
 
     # The last entry (if any) processed was a match. +ai+ and +bj+ point just
     # past the last matching lines in their sequences.
-    while (ai < a_size) or (bj < b_size)
+    while (ai < a_size) || (bj < b_size)
       # last A?
-      if ai == a_size and bj < b_size
-        if callbacks.respond_to?(:finished_a) and !run_finished_a
+      if ai == a_size && bj < b_size
+        if callbacks.respond_to?(:finished_a) && !run_finished_a
           ax = string ? seq1[-1, 1] : seq1[-1]
           bx = string ? seq2[bj, 1] : seq2[bj]
-          event = Diff::LCS::ContextChange.new('>', (a_size - 1), ax, bj, bx)
+          event = Diff::LCS::ContextChange.new(">", (a_size - 1), ax, bj, bx)
           event = yield event if block_given?
           callbacks.finished_a(event)
           run_finished_a = true
@@ -340,7 +340,7 @@ class << Diff::LCS
           ax = string ? seq1[ai, 1] : seq1[ai]
           loop do
             bx = string ? seq2[bj, 1] : seq2[bj]
-            event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+            event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
             event = yield event if block_given?
             callbacks.discard_b(event)
             bj += 1
@@ -350,11 +350,11 @@ class << Diff::LCS
       end
 
       # last B?
-      if bj == b_size and ai < a_size
-        if callbacks.respond_to?(:finished_b) and !run_finished_b
+      if bj == b_size && ai < a_size
+        if callbacks.respond_to?(:finished_b) && !run_finished_b
           ax = string ? seq1[ai, 1] : seq1[ai]
           bx = string ? seq2[-1, 1] : seq2[-1]
-          event = Diff::LCS::ContextChange.new('<', ai, ax, (b_size - 1), bx)
+          event = Diff::LCS::ContextChange.new("<", ai, ax, (b_size - 1), bx)
           event = yield event if block_given?
           callbacks.finished_b(event)
           run_finished_b = true
@@ -362,7 +362,7 @@ class << Diff::LCS
           bx = string ? seq2[bj, 1] : seq2[bj]
           loop do
             ax = string ? seq1[ai, 1] : seq1[ai]
-            event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+            event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
             event = yield event if block_given?
             callbacks.discard_a(event)
             ai += 1
@@ -374,7 +374,7 @@ class << Diff::LCS
       if ai < a_size
         ax = string ? seq1[ai, 1] : seq1[ai]
         bx = string ? seq2[bj, 1] : seq2[bj]
-        event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+        event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
         event = yield event if block_given?
         callbacks.discard_a(event)
         ai += 1
@@ -383,7 +383,7 @@ class << Diff::LCS
       if bj < b_size
         ax = string ? seq1[ai, 1] : seq1[ai]
         bx = string ? seq2[bj, 1] : seq2[bj]
-        event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+        event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
         event = yield event if block_given?
         callbacks.discard_b(event)
         bj += 1
@@ -478,14 +478,14 @@ class << Diff::LCS
     b_size = seq2.size
     ai = bj = mb = 0
     ma = -1
-    string = seq1.kind_of?(String)
+    string = seq1.is_a?(String)
 
     # Process all the lines in the match vector.
     loop do
       # Find next match indices +ma+ and +mb+
       loop do
         ma += 1
-        break unless ma < matches.size and matches[ma].nil?
+        break unless ma < matches.size && matches[ma].nil?
       end
 
       break if ma >= matches.size # end of matches?
@@ -493,36 +493,36 @@ class << Diff::LCS
       mb = matches[ma]
 
       # Change(seq2)
-      while (ai < ma) or (bj < mb)
+      while (ai < ma) || (bj < mb)
         ax = string ? seq1[ai, 1] : seq1[ai]
         bx = string ? seq2[bj, 1] : seq2[bj]
 
         case [(ai < ma), (bj < mb)]
         when [true, true]
           if callbacks.respond_to?(:change)
-            event = Diff::LCS::ContextChange.new('!', ai, ax, bj, bx)
+            event = Diff::LCS::ContextChange.new("!", ai, ax, bj, bx)
             event = yield event if block_given?
             callbacks.change(event)
             ai += 1
           else
-            event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+            event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
             event = yield event if block_given?
             callbacks.discard_a(event)
             ai += 1
             ax = string ? seq1[ai, 1] : seq1[ai]
-            event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+            event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
             event = yield event if block_given?
             callbacks.discard_b(event)
           end
 
           bj += 1
         when [true, false]
-          event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_a(event)
           ai += 1
         when [false, true]
-          event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_b(event)
           bj += 1
@@ -532,43 +532,43 @@ class << Diff::LCS
       # Match
       ax = string ? seq1[ai, 1] : seq1[ai]
       bx = string ? seq2[bj, 1] : seq2[bj]
-      event = Diff::LCS::ContextChange.new('=', ai, ax, bj, bx)
+      event = Diff::LCS::ContextChange.new("=", ai, ax, bj, bx)
       event = yield event if block_given?
       callbacks.match(event)
       ai += 1
       bj += 1
     end
 
-    while (ai < a_size) or (bj < b_size)
+    while (ai < a_size) || (bj < b_size)
       ax = string ? seq1[ai, 1] : seq1[ai]
       bx = string ? seq2[bj, 1] : seq2[bj]
 
       case [(ai < a_size), (bj < b_size)]
       when [true, true]
         if callbacks.respond_to?(:change)
-          event = Diff::LCS::ContextChange.new('!', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("!", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.change(event)
           ai += 1
         else
-          event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_a(event)
           ai += 1
           ax = string ? seq1[ai, 1] : seq1[ai]
-          event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+          event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
           event = yield event if block_given?
           callbacks.discard_b(event)
         end
 
         bj += 1
       when [true, false]
-        event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
+        event = Diff::LCS::ContextChange.new("-", ai, ax, bj, bx)
         event = yield event if block_given?
         callbacks.discard_a(event)
         ai += 1
       when [false, true]
-        event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
+        event = Diff::LCS::ContextChange.new("+", ai, ax, bj, bx)
         event = yield event if block_given?
         callbacks.discard_b(event)
         bj += 1
@@ -576,10 +576,12 @@ class << Diff::LCS
     end
   end
 
-  PATCH_MAP = { #:nodoc:
-    :patch => { '+' => '+', '-' => '-', '!' => '!', '=' => '=' }.freeze,
-    :unpatch => { '+' => '-', '-' => '+', '!' => '!', '=' => '=' }.freeze
+  # standard:disable Style/HashSyntax
+  PATCH_MAP = { # :nodoc:
+    :patch => {"+" => "+", "-" => "-", "!" => "!", "=" => "="}.freeze,
+    :unpatch => {"+" => "-", "-" => "+", "!" => "!", "=" => "="}.freeze
   }.freeze
+  # standard:enable Style/HashSyntax
 
   # Applies a +patchset+ to the sequence +src+ according to the +direction+
   # (<tt>:patch</tt> or <tt>:unpatch</tt>), producing a new sequence.
@@ -627,7 +629,7 @@ class << Diff::LCS
 
     return src.respond_to?(:dup) ? src.dup : src unless has_changes
 
-    string = src.kind_of?(String)
+    string = src.is_a?(String)
     # Start with a new empty type of the source's class
     res = src.class.new
 
@@ -655,14 +657,14 @@ class << Diff::LCS
         end
 
         case action
-        when '-' # Remove details from the old string
+        when "-" # Remove details from the old string
           while ai < op
             res << (string ? src[ai, 1] : src[ai])
             ai += 1
             bj += 1
           end
           ai += 1
-        when '+'
+        when "+"
           while bj < np
             res << (string ? src[ai, 1] : src[ai])
             ai += 1
@@ -671,7 +673,7 @@ class << Diff::LCS
 
           res << el
           bj += 1
-        when '='
+        when "="
           # This only appears in sdiff output with the SDiff callback.
           # Therefore, we only need to worry about dealing with a single
           # element.
@@ -679,7 +681,7 @@ class << Diff::LCS
 
           ai += 1
           bj += 1
-        when '!'
+        when "!"
           while ai < op
             res << (string ? src[ai, 1] : src[ai])
             ai += 1
@@ -693,14 +695,14 @@ class << Diff::LCS
         end
       when Diff::LCS::Change
         case action
-        when '-'
+        when "-"
           while ai < change.position
             res << (string ? src[ai, 1] : src[ai])
             ai += 1
             bj += 1
           end
           ai += 1
-        when '+'
+        when "+"
           while bj < change.position
             res << (string ? src[ai, 1] : src[ai])
             ai += 1
@@ -736,4 +738,4 @@ class << Diff::LCS
   end
 end
 
-require 'diff/lcs/backports'
+require "diff/lcs/backports"
diff --git a/lib/diff/lcs/array.rb b/lib/diff/lcs/array.rb
index 5c250f6..663918a 100644
--- a/lib/diff/lcs/array.rb
+++ b/lib/diff/lcs/array.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'diff/lcs'
+require "diff/lcs"
 
 class Array
   include Diff::LCS
diff --git a/lib/diff/lcs/backports.rb b/lib/diff/lcs/backports.rb
index 642fc9c..3d2a768 100644
--- a/lib/diff/lcs/backports.rb
+++ b/lib/diff/lcs/backports.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
 unless 0.respond_to?(:positive?)
-  class Fixnum # rubocop:disable Lint/UnifiedInteger, Style/Documentation
+  class Fixnum # standard:disable Lint/UnifiedInteger
     def positive?
-      self > 0 # rubocop:disable Style/NumericPredicate
+      self > 0
     end
   end
 end
diff --git a/lib/diff/lcs/block.rb b/lib/diff/lcs/block.rb
index 430702d..226ed6f 100644
--- a/lib/diff/lcs/block.rb
+++ b/lib/diff/lcs/block.rb
@@ -25,13 +25,13 @@ class Diff::LCS::Block
   def op
     case [@remove.empty?, @insert.empty?]
     when [false, false]
-      '!'
+      "!"
     when [false, true]
-      '-'
+      "-"
     when [true, false]
-      '+'
+      "+"
     else # [true, true]
-      '^'
+      "^"
     end
   end
 end
diff --git a/lib/diff/lcs/callbacks.rb b/lib/diff/lcs/callbacks.rb
index 2a7665b..2c5a779 100644
--- a/lib/diff/lcs/callbacks.rb
+++ b/lib/diff/lcs/callbacks.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require 'diff/lcs/change'
+require "diff/lcs/change"
 
-module Diff::LCS # rubocop:disable Style/Documentation
+module Diff::LCS
   # This callback object implements the default set of callback events,
   # which only returns the event itself. Note that #finished_a and
   # #finished_b are not implemented -- I haven't yet figured out where they
@@ -50,7 +50,9 @@ module Diff::LCS # rubocop:disable Style/Documentation
   BalancedCallbacks = DefaultCallbacks
 
   def self.callbacks_for(callbacks)
-    callbacks.new rescue callbacks
+    callbacks.new
+  rescue
+    callbacks
   end
 end
 
@@ -107,7 +109,7 @@ class Diff::LCS::DiffCallbacks
   # Returns the difference set collected during the diff process.
   attr_reader :diffs
 
-  def initialize # :yields self:
+  def initialize # :yields: self
     @hunk = []
     @diffs = []
 
@@ -131,11 +133,11 @@ class Diff::LCS::DiffCallbacks
   end
 
   def discard_a(event)
-    @hunk << Diff::LCS::Change.new('-', event.old_position, event.old_element)
+    @hunk << Diff::LCS::Change.new("-", event.old_position, event.old_element)
   end
 
   def discard_b(event)
-    @hunk << Diff::LCS::Change.new('+', event.new_position, event.new_element)
+    @hunk << Diff::LCS::Change.new("+", event.new_position, event.new_element)
   end
 
   def finish_hunk
@@ -302,7 +304,7 @@ class Diff::LCS::SDiffCallbacks
   # Returns the difference set collected during the diff process.
   attr_reader :diffs
 
-  def initialize #:yields self:
+  def initialize # :yields: self
     @diffs = []
     yield self if block_given?
   end
diff --git a/lib/diff/lcs/change.rb b/lib/diff/lcs/change.rb
index 76faf83..c86f102 100644
--- a/lib/diff/lcs/change.rb
+++ b/lib/diff/lcs/change.rb
@@ -10,7 +10,7 @@ class Diff::LCS::Change
   # (no change), '!' (changed), '<' (tail changes from first sequence), or
   # '>' (tail changes from second sequence). The last two ('<>') are only
   # found with Diff::LCS::diff and Diff::LCS::sdiff.
-  VALID_ACTIONS = %w(+ - = ! > <).freeze
+  VALID_ACTIONS = %w[+ - = ! > <].freeze
 
   def self.valid_action?(action)
     VALID_ACTIONS.include? action
@@ -28,7 +28,7 @@ class Diff::LCS::Change
     @action, @position, @element = *args
 
     fail "Invalid Change Action '#{@action}'" unless Diff::LCS::Change.valid_action?(@action)
-    fail 'Invalid Position Type' unless @position.kind_of? IntClass
+    fail "Invalid Position Type" unless @position.is_a? IntClass
   end
 
   def inspect(*_args)
@@ -39,7 +39,7 @@ class Diff::LCS::Change
     [@action, @position, @element]
   end
 
-  alias to_ary to_a
+  alias_method :to_ary, :to_a
 
   def self.from_a(arr)
     arr = arr.flatten(1)
@@ -49,7 +49,7 @@ class Diff::LCS::Change
     when 3
       Diff::LCS::Change.new(*(arr[0...3]))
     else
-      fail 'Invalid change array format provided.'
+      fail "Invalid change array format provided."
     end
   end
 
@@ -70,27 +70,27 @@ class Diff::LCS::Change
   end
 
   def adding?
-    @action == '+'
+    @action == "+"
   end
 
   def deleting?
-    @action == '-'
+    @action == "-"
   end
 
   def unchanged?
-    @action == '='
+    @action == "="
   end
 
   def changed?
-    @action == '!'
+    @action == "!"
   end
 
   def finished_a?
-    @action == '>'
+    @action == ">"
   end
 
   def finished_b?
-    @action == '<'
+    @action == "<"
   end
 end
 
@@ -115,8 +115,8 @@ class Diff::LCS::ContextChange < Diff::LCS::Change
     @action, @old_position, @old_element, @new_position, @new_element = *args
 
     fail "Invalid Change Action '#{@action}'" unless Diff::LCS::Change.valid_action?(@action)
-    fail 'Invalid (Old) Position Type' unless @old_position.nil? or @old_position.kind_of? IntClass
-    fail 'Invalid (New) Position Type' unless @new_position.nil? or @new_position.kind_of? IntClass
+    fail "Invalid (Old) Position Type" unless @old_position.nil? || @old_position.is_a?(IntClass)
+    fail "Invalid (New) Position Type" unless @new_position.nil? || @new_position.is_a?(IntClass)
   end
 
   def to_a
@@ -127,7 +127,7 @@ class Diff::LCS::ContextChange < Diff::LCS::Change
     ]
   end
 
-  alias to_ary to_a
+  alias_method :to_ary, :to_a
 
   def self.from_a(arr)
     Diff::LCS::Change.from_a(arr)
@@ -139,15 +139,15 @@ class Diff::LCS::ContextChange < Diff::LCS::Change
     ea = event.to_a
 
     case ea[0]
-    when '-'
+    when "-"
       ea[2][1] = nil
-    when '<'
-      ea[0] = '-'
+    when "<"
+      ea[0] = "-"
       ea[2][1] = nil
-    when '+'
+    when "+"
       ea[1][1] = nil
-    when '>'
-      ea[0] = '+'
+    when ">"
+      ea[0] = "+"
       ea[1][1] = nil
     end
 
diff --git a/lib/diff/lcs/htmldiff.rb b/lib/diff/lcs/htmldiff.rb
index f12220b..54adc2a 100644
--- a/lib/diff/lcs/htmldiff.rb
+++ b/lib/diff/lcs/htmldiff.rb
@@ -1,15 +1,15 @@
 # frozen_string_literal: true
 
-require 'cgi'
+require "cgi"
 
 # Produce a simple HTML diff view.
 class Diff::LCS::HTMLDiff
   class << self
-    attr_accessor :can_expand_tabs #:nodoc:
+    attr_accessor :can_expand_tabs # :nodoc:
   end
   self.can_expand_tabs = true
 
-  class Callbacks #:nodoc:
+  class Callbacks # :nodoc:
     attr_accessor :output
     attr_accessor :match_class
     attr_accessor :only_a_class
@@ -19,14 +19,14 @@ class Diff::LCS::HTMLDiff
       @output = output
       options ||= {}
 
-      @match_class = options[:match_class] || 'match'
-      @only_a_class = options[:only_a_class] || 'only_a'
-      @only_b_class = options[:only_b_class] || 'only_b'
+      @match_class = options[:match_class] || "match"
+      @only_a_class = options[:only_a_class] || "only_a"
+      @only_b_class = options[:only_b_class] || "only_b"
     end
 
     def htmlize(element, css_class)
-      element = '&nbsp;' if element.empty?
-      %Q(<pre class="#{__send__(css_class)}">#{element}</pre>\n)
+      element = "&nbsp;" if element.empty?
+      %(<pre class="#{__send__(css_class)}">#{element}</pre>\n)
     end
     private :htmlize
 
@@ -46,13 +46,16 @@ class Diff::LCS::HTMLDiff
     end
   end
 
+  # standard:disable Style/HashSyntax
   DEFAULT_OPTIONS = {
     :expand_tabs => nil,
     :output => nil,
     :css => nil,
     :title => nil
   }.freeze
+  # standard:enable Style/HashSyntax
 
+  # standard:disable Layout/HeredocIndentation
   DEFAULT_CSS = <<-CSS
 body { margin: 0; }
 .diff
@@ -86,11 +89,12 @@ pre
 }
 h1 { margin-left: 2em; }
   CSS
+  # standard:enable Layout/HeredocIndentation
 
   def initialize(left, right, options = nil)
-    @left     = left
-    @right    = right
-    @options  = options
+    @left = left
+    @right = right
+    @options = options
 
     @options = DEFAULT_OPTIONS.dup if @options.nil?
   end
@@ -103,7 +107,7 @@ h1 { margin-left: 2em; }
 
     @options[:css] ||= DEFAULT_CSS.dup
 
-    @options[:title] ||= 'diff'
+    @options[:title] ||= "diff"
   end
   private :verify_options
 
@@ -116,13 +120,14 @@ h1 { margin-left: 2em; }
       formatter = Text::Format.new
       formatter.tabstop = @options[:expand_tabs]
 
-      @left.map! do |line| formatter.expand(line.chomp) end
-      @right.map! do |line| formatter.expand(line.chomp) end
+      @left.map! { |line| formatter.expand(line.chomp) }
+      @right.map! { |line| formatter.expand(line.chomp) }
     end
 
-    @left.map! do |line| CGI.escapeHTML(line.chomp) end
-    @right.map! do |line| CGI.escapeHTML(line.chomp) end
+    @left.map! { |line| CGI.escapeHTML(line.chomp) }
+    @right.map! { |line| CGI.escapeHTML(line.chomp) }
 
+    # standard:disable Layout/HeredocIndentation
     @options[:output] << <<-OUTPUT
 <html>
   <head>
@@ -137,14 +142,17 @@ h1 { margin-left: 2em; }
     <span class="only_b">Only in New</span></p>
     <div class="diff">
     OUTPUT
+    # standard:enable Layout/HeredocIndentation
 
     callbacks = Callbacks.new(@options[:output])
     Diff::LCS.traverse_sequences(@left, @right, callbacks)
 
+    # standard:disable Layout/HeredocIndentation
     @options[:output] << <<-OUTPUT
     </div>
   </body>
 </html>
     OUTPUT
+    # standard:enable Layout/HeredocIndentation
   end
 end
diff --git a/lib/diff/lcs/hunk.rb b/lib/diff/lcs/hunk.rb
index 49b520e..2cef5ed 100644
--- a/lib/diff/lcs/hunk.rb
+++ b/lib/diff/lcs/hunk.rb
@@ -1,13 +1,13 @@
 # frozen_string_literal: true
 
-require 'diff/lcs/block'
+require "diff/lcs/block"
 
 # A Hunk is a group of Blocks which overlap because of the context surrounding
 # each block. (So if we're not using context, every hunk will contain one
 # block.) Used in the diff program (bin/ldiff).
 class Diff::LCS::Hunk
-  OLD_DIFF_OP_ACTION = { '+' => 'a', '-' => 'd', '!' => 'c' }.freeze #:nodoc:
-  ED_DIFF_OP_ACTION = { '+' => 'a', '-' => 'd', '!' => 'c' }.freeze #:nodoc:
+  OLD_DIFF_OP_ACTION = {"+" => "a", "-" => "d", "!" => "c"}.freeze # :nodoc:
+  ED_DIFF_OP_ACTION = {"+" => "a", "-" => "d", "!" => "c"}.freeze # :nodoc:
 
   private_constant :OLD_DIFF_OP_ACTION, :ED_DIFF_OP_ACTION if respond_to?(:private_constant)
 
@@ -22,7 +22,7 @@ class Diff::LCS::Hunk
     end
 
     if String.method_defined?(:encoding)
-      @preferred_data_encoding = data_old.fetch(0, data_new.fetch(0, '')).encoding
+      @preferred_data_encoding = data_old.fetch(0) { data_new.fetch(0, "") }.encoding
     end
 
     @data_old = data_old
@@ -33,7 +33,6 @@ class Diff::LCS::Hunk
     @file_length_difference = after # The caller must get this manually
     @max_diff_size = @blocks.map { |e| e.diff_size.abs }.max
 
-
     # Save the start & end of each array. If the array doesn't exist (e.g.,
     # we're only adding items in this block), then figure out the line number
     # based on the line number of the other file and the current difference in
@@ -54,8 +53,8 @@ class Diff::LCS::Hunk
 
     @start_old = a1 || (b1 - before)
     @start_new = b1 || (a1 + before)
-    @end_old   = a2 || (b2 - after)
-    @end_new   = b2 || (a2 + after)
+    @end_old = a2 || (b2 - after)
+    @end_new = b2 || (a2 + after)
 
     self.flag_context = flag_context
   end
@@ -67,10 +66,10 @@ class Diff::LCS::Hunk
 
   # Change the "start" and "end" fields to note that context should be added
   # to this hunk.
-  attr_accessor :flag_context # rubocop:disable Layout/EmptyLinesAroundAttributeAccessor
+  attr_accessor :flag_context
   undef :flag_context=
-  def flag_context=(context) #:nodoc: # rubocop:disable Lint/DuplicateMethods
-    return if context.nil? or context.zero?
+  def flag_context=(context) # :nodoc: # standard:disable Lint/DuplicateMethods
+    return if context.nil? || context.zero?
 
     add_start = context > @start_old ? @start_old : context
 
@@ -102,7 +101,7 @@ class Diff::LCS::Hunk
     @start_new = hunk.start_new
     blocks.unshift(*hunk.blocks)
   end
-  alias unshift merge
+  alias_method :unshift, :merge
 
   # Determines whether there is an overlap between this hunk and the
   # provided hunk. This will be true if the difference between the two hunks
@@ -133,24 +132,24 @@ class Diff::LCS::Hunk
   # Note that an old diff can't have any context. Therefore, we know that
   # there's only one block in the hunk.
   def old_diff(_last = false)
-    warn 'Expecting only one block in an old diff hunk!' if @blocks.size > 1
+    warn "Expecting only one block in an old diff hunk!" if @blocks.size > 1
 
     block = @blocks[0]
 
     # Calculate item number range. Old diff range is just like a context
     # diff range, except the ranges are on one line with the action between
     # them.
-    s = encode("#{context_range(:old, ',')}#{OLD_DIFF_OP_ACTION[block.op]}#{context_range(:new, ',')}\n")
+    s = encode("#{context_range(:old, ",")}#{OLD_DIFF_OP_ACTION[block.op]}#{context_range(:new, ",")}\n")
     # If removing anything, just print out all the remove lines in the hunk
     # which is just all the remove lines in the block.
     unless block.remove.empty?
-      @data_old[@start_old..@end_old].each { |e| s << encode('< ') + e.chomp + encode("\n") }
+      @data_old[@start_old..@end_old].each { |e| s << encode("< ") + e.chomp + encode("\n") }
     end
 
-    s << encode("---\n") if block.op == '!'
+    s << encode("---\n") if block.op == "!"
 
     unless block.insert.empty?
-      @data_new[@start_new..@end_new].each { |e| s << encode('> ') + e.chomp + encode("\n") }
+      @data_new[@start_new..@end_new].each { |e| s << encode("> ") + e.chomp + encode("\n") }
     end
 
     s
@@ -172,7 +171,9 @@ class Diff::LCS::Hunk
     # file -- don't take removed items into account.
     lo, hi, num_added, num_removed = @start_old, @end_old, 0, 0
 
-    outlist = @data_old[lo..hi].map { |e| String.new("#{encode(' ')}#{e.chomp}") }
+    # standard:disable Performance/UnfreezeString
+    outlist = @data_old[lo..hi].map { |e| String.new("#{encode(" ")}#{e.chomp}") }
+    # standard:enable Performance/UnfreezeString
 
     last_block = blocks[-1]
 
@@ -183,7 +184,7 @@ class Diff::LCS::Hunk
 
     @blocks.each do |block|
       block.remove.each do |item|
-        op     = item.action.to_s # -
+        op = item.action.to_s # -
         offset = item.position - lo + num_added
         outlist[offset][0, 1] = encode(op)
         num_removed += 1
@@ -195,7 +196,7 @@ class Diff::LCS::Hunk
       end
 
       block.insert.each do |item|
-        op     = item.action.to_s # +
+        op = item.action.to_s # +
         offset = item.position - @start_new + num_removed
         outlist[offset, 0] = encode(op) + @data_new[item.position].chomp
         num_added += 1
@@ -212,8 +213,8 @@ class Diff::LCS::Hunk
 
   def context_diff(last = false)
     s = encode("***************\n")
-    s << encode("*** #{context_range(:old, ',', last)} ****\n")
-    r = context_range(:new, ',', last)
+    s << encode("*** #{context_range(:old, ",", last)} ****\n")
+    r = context_range(:new, ",", last)
 
     if last
       old_missing_newline = missing_last_newline?(@data_old)
@@ -226,7 +227,9 @@ class Diff::LCS::Hunk
     removes = @blocks.reject { |e| e.remove.empty? }
 
     unless removes.empty?
-      outlist = @data_old[lo..hi].map { |e| String.new("#{encode('  ')}#{e.chomp}") }
+      # standard:disable Performance/UnfreezeString
+      outlist = @data_old[lo..hi].map { |e| String.new("#{encode("  ")}#{e.chomp}") }
+      # standard:enable Performance/UnfreezeString
 
       last_block = removes[-1]
 
@@ -248,7 +251,9 @@ class Diff::LCS::Hunk
     inserts = @blocks.reject { |e| e.insert.empty? }
 
     unless inserts.empty?
-      outlist = @data_new[lo..hi].map { |e| String.new("#{encode('  ')}#{e.chomp}") }
+      # standard:disable Performance/UnfreezeString
+      outlist = @data_new[lo..hi].map { |e| String.new("#{encode("  ")}#{e.chomp}") }
+      # standard:enable Performance/UnfreezeString
 
       last_block = inserts[-1]
 
@@ -269,13 +274,13 @@ class Diff::LCS::Hunk
   private :context_diff
 
   def ed_diff(format, _last = false)
-    warn 'Expecting only one block in an old diff hunk!' if @blocks.size > 1
+    warn "Expecting only one block in an old diff hunk!" if @blocks.size > 1
 
     s =
       if format == :reverse_ed
-        encode("#{ED_DIFF_OP_ACTION[@blocks[0].op]}#{context_range(:old, ',')}\n")
+        encode("#{ED_DIFF_OP_ACTION[@blocks[0].op]}#{context_range(:old, ",")}\n")
       else
-        encode("#{context_range(:old, ' ')}#{ED_DIFF_OP_ACTION[@blocks[0].op]}\n")
+        encode("#{context_range(:old, " ")}#{ED_DIFF_OP_ACTION[@blocks[0].op]}\n")
       end
 
     unless @blocks[0].insert.empty?
diff --git a/lib/diff/lcs/internals.rb b/lib/diff/lcs/internals.rb
index ef77667..8a9160a 100644
--- a/lib/diff/lcs/internals.rb
+++ b/lib/diff/lcs/internals.rb
@@ -13,7 +13,7 @@ class << Diff::LCS
 
     if block
       callbacks.diffs.map do |hunk|
-        if hunk.kind_of? Array
+        if hunk.is_a? Array
           hunk.map { |hunk_block| block[hunk_block] }
         else
           block[hunk]
@@ -45,14 +45,14 @@ class << Diff::LCS::Internals
     vector = []
 
     # Collect any common elements at the beginning...
-    while (a_start <= a_finish) and (b_start <= b_finish) and (a[a_start] == b[b_start])
+    while (a_start <= a_finish) && (b_start <= b_finish) && (a[a_start] == b[b_start])
       vector[a_start] = b_start
       a_start += 1
       b_start += 1
     end
 
     # Now the end...
-    while (a_start <= a_finish) and (b_start <= b_finish) and (a[a_finish] == b[b_finish])
+    while (a_start <= a_finish) && (b_start <= b_finish) && (a[a_finish] == b[b_finish])
       vector[a_finish] = b_finish
       a_finish -= 1
       b_finish -= 1
@@ -63,8 +63,8 @@ class << Diff::LCS::Internals
     b_matches = position_hash(b, b_start..b_finish)
 
     thresh = []
-    links  = []
-    string = a.kind_of?(String)
+    links = []
+    string = a.is_a?(String)
 
     (a_start..a_finish).each do |i|
       ai = string ? a[i, 1] : a[i]
@@ -75,7 +75,7 @@ class << Diff::LCS::Internals
         # it may have an optimization purpose
         # An attempt to remove it: https://github.com/halostatue/diff-lcs/pull/72
         # Why it is reintroduced: https://github.com/halostatue/diff-lcs/issues/78
-        if k and (thresh[k] > j) and (thresh[k - 1] < j)
+        if k && (thresh[k] > j) && (thresh[k - 1] < j)
           thresh[k] = j
         else
           k = replace_next_larger(thresh, j, k)
@@ -100,7 +100,7 @@ class << Diff::LCS::Internals
   # the object form of same) and detection of whether the patchset represents
   # changes to be made.
   def analyze_patchset(patchset, depth = 0)
-    fail 'Patchset too complex' if depth > 1
+    fail "Patchset too complex" if depth > 1
 
     has_changes = false
     new_patchset = []
@@ -145,7 +145,7 @@ class << Diff::LCS::Internals
   # Diff::LCS::Change as its source, as an array will cause the creation
   # of one of the above.
   def intuit_diff_direction(src, patchset, limit = nil)
-    string = src.kind_of?(String)
+    string = src.is_a?(String)
     count = left_match = left_miss = right_match = right_miss = 0
 
     patchset.each do |change|
@@ -157,22 +157,22 @@ class << Diff::LCS::Internals
         re = string ? src[change.new_position, 1] : src[change.new_position]
 
         case change.action
-        when '-' # Remove details from the old string
+        when "-" # Remove details from the old string
           if le == change.old_element
             left_match += 1
           else
             left_miss += 1
           end
-        when '+'
+        when "+"
           if re == change.new_element
             right_match += 1
           else
             right_miss += 1
           end
-        when '='
+        when "="
           left_miss += 1 if le != change.old_element
           right_miss += 1 if re != change.new_element
-        when '!'
+        when "!"
           if le == change.old_element
             left_match += 1
           elsif re == change.new_element
@@ -189,19 +189,19 @@ class << Diff::LCS::Internals
         element = string ? src[change.position, 1] : src[change.position]
 
         case change.action
-        when '-'
+        when "-"
           if element == change.element
             left_match += 1
           else
             left_miss += 1
           end
-        when '+'
+        when "+"
           if element == change.element
             right_match += 1
           else
             right_miss += 1
           end
-        when '='
+        when "="
           if element != change.element
             left_miss += 1
             right_miss += 1
@@ -251,7 +251,7 @@ enumerable as either source or destination value."
   # This operation preserves the sort order.
   def replace_next_larger(enum, value, last_index = nil)
     # Off the end?
-    if enum.empty? or (value > enum[-1])
+    if enum.empty? || (value > enum[-1])
       enum << value
       return enum.size - 1
     end
@@ -296,7 +296,7 @@ enumerable as either source or destination value."
   # positions it occupies in the Enumerable, optionally restricted to the
   # elements specified in the range of indexes specified by +interval+.
   def position_hash(enum, interval)
-    string = enum.kind_of?(String)
+    string = enum.is_a?(String)
     hash = Hash.new { |h, k| h[k] = [] }
     interval.each do |i|
       k = string ? enum[i, 1] : enum[i]
diff --git a/lib/diff/lcs/ldiff.rb b/lib/diff/lcs/ldiff.rb
index 17b374c..961458c 100644
--- a/lib/diff/lcs/ldiff.rb
+++ b/lib/diff/lcs/ldiff.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
 
-require 'optparse'
-require 'ostruct'
-require 'diff/lcs/hunk'
+require "optparse"
+require "ostruct"
+require "diff/lcs/hunk"
 
-module Diff::LCS::Ldiff #:nodoc:
+module Diff::LCS::Ldiff # :nodoc:
+  # standard:disable Layout/HeredocIndentation
   BANNER = <<-COPYRIGHT
 ldiff #{Diff::LCS::VERSION}
   Copyright 2004-2019 Austin Ziegler
@@ -16,60 +17,61 @@ ldiff #{Diff::LCS::VERSION}
   the terms of the GPL version 2 (or later), the Perl Artistic licence, or the
   MIT licence.
   COPYRIGHT
+  # standard:enable Layout/HeredocIndentation
 end
 
 class << Diff::LCS::Ldiff
-  attr_reader :format, :lines #:nodoc:
-  attr_reader :file_old, :file_new #:nodoc:
-  attr_reader :data_old, :data_new #:nodoc:
+  attr_reader :format, :lines # :nodoc:
+  attr_reader :file_old, :file_new # :nodoc:
+  attr_reader :data_old, :data_new # :nodoc:
 
-  def run(args, _input = $stdin, output = $stdout, error = $stderr) #:nodoc:
+  def run(args, _input = $stdin, output = $stdout, error = $stderr) # :nodoc:
     @binary = nil
 
     args.options do |o|
       o.banner = "Usage: #{File.basename($0)} [options] oldfile newfile"
-      o.separator ''
+      o.separator ""
       o.on(
-        '-c', '-C', '--context [LINES]', Integer,
-        'Displays a context diff with LINES lines', 'of context. Default 3 lines.'
+        "-c", "-C", "--context [LINES]", Integer,
+        "Displays a context diff with LINES lines", "of context. Default 3 lines."
       ) do |ctx|
         @format = :context
-        @lines  = ctx || 3
+        @lines = ctx || 3
       end
       o.on(
-        '-u', '-U', '--unified [LINES]', Integer,
-        'Displays a unified diff with LINES lines', 'of context. Default 3 lines.'
+        "-u", "-U", "--unified [LINES]", Integer,
+        "Displays a unified diff with LINES lines", "of context. Default 3 lines."
       ) do |ctx|
         @format = :unified
-        @lines  = ctx || 3
+        @lines = ctx || 3
       end
-      o.on('-e', 'Creates an \'ed\' script to change', 'oldfile to newfile.') do |_ctx|
+      o.on("-e", "Creates an 'ed' script to change", "oldfile to newfile.") do |_ctx|
         @format = :ed
       end
-      o.on('-f', 'Creates an \'ed\' script to change', 'oldfile to newfile in reverse order.') do |_ctx|
+      o.on("-f", "Creates an 'ed' script to change", "oldfile to newfile in reverse order.") do |_ctx|
         @format = :reverse_ed
       end
       o.on(
-        '-a', '--text',
-        'Treat the files as text and compare them', 'line-by-line, even if they do not seem', 'to be text.'
+        "-a", "--text",
+        "Treat the files as text and compare them", "line-by-line, even if they do not seem", "to be text."
       ) do |_txt|
         @binary = false
       end
-      o.on('--binary', 'Treats the files as binary.') do |_bin|
+      o.on("--binary", "Treats the files as binary.") do |_bin|
         @binary = true
       end
-      o.on('-q', '--brief', 'Report only whether or not the files', 'differ, not the details.') do |_ctx|
+      o.on("-q", "--brief", "Report only whether or not the files", "differ, not the details.") do |_ctx|
         @format = :report
       end
-      o.on_tail('--help', 'Shows this text.') do
+      o.on_tail("--help", "Shows this text.") do
         error << o
         return 0
       end
-      o.on_tail('--version', 'Shows the version of Diff::LCS.') do
+      o.on_tail("--version", "Shows the version of Diff::LCS.") do
         error << Diff::LCS::Ldiff::BANNER
         return 0
       end
-      o.on_tail ''
+      o.on_tail ""
       o.on_tail 'By default, runs produces an "old-style" diff, with output like UNIX diff.'
       o.parse!
     end
@@ -81,17 +83,17 @@ class << Diff::LCS::Ldiff
 
     # Defaults are for old-style diff
     @format ||= :old
-    @lines  ||= 0
+    @lines ||= 0
 
     file_old, file_new = *ARGV
 
     case @format
     when :context
-      char_old = '*' * 3
-      char_new = '-' * 3
+      char_old = "*" * 3
+      char_new = "-" * 3
     when :unified
-      char_old = '-' * 3
-      char_new = '+' * 3
+      char_old = "-" * 3
+      char_new = "+" * 3
     end
 
     # After we've read up to a certain point in each file, the number of
@@ -128,10 +130,10 @@ class << Diff::LCS::Ldiff
       return 1
     end
 
-    if (@format == :unified) or (@format == :context)
-      ft = File.stat(file_old).mtime.localtime.strftime('%Y-%m-%d %H:%M:%S.000000000 %z')
+    if (@format == :unified) || (@format == :context)
+      ft = File.stat(file_old).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.000000000 %z")
       output << "#{char_old} #{file_old}\t#{ft}\n"
-      ft = File.stat(file_new).mtime.localtime.strftime('%Y-%m-%d %H:%M:%S.000000000 %z')
+      ft = File.stat(file_new).mtime.localtime.strftime("%Y-%m-%d %H:%M:%S.000000000 %z")
       output << "#{char_new} #{file_new}\t#{ft}\n"
     end
 
@@ -150,7 +152,7 @@ class << Diff::LCS::Ldiff
         file_length_difference = hunk.file_length_difference
 
         next unless oldhunk
-        next if @lines.positive? and hunk.merge(oldhunk)
+        next if @lines.positive? && hunk.merge(oldhunk)
 
         output << oldhunk.diff(@format)
         output << "\n" if @format == :unified
diff --git a/spec/change_spec.rb b/spec/change_spec.rb
index b8d3443..42533ae 100644
--- a/spec/change_spec.rb
+++ b/spec/change_spec.rb
@@ -1,89 +1,89 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
 describe Diff::LCS::Change do
-  describe 'an add' do
-    subject { described_class.new('+', 0, 'element') }
-    it { should_not be_deleting   }
-    it { should     be_adding     }
-    it { should_not be_unchanged  }
-    it { should_not be_changed    }
+  describe "an add" do
+    subject { described_class.new("+", 0, "element") }
+    it { should_not be_deleting }
+    it { should be_adding }
+    it { should_not be_unchanged }
+    it { should_not be_changed }
     it { should_not be_finished_a }
     it { should_not be_finished_b }
   end
 
-  describe 'a delete' do
-    subject { described_class.new('-', 0, 'element') }
-    it { should     be_deleting   }
-    it { should_not be_adding     }
-    it { should_not be_unchanged  }
-    it { should_not be_changed    }
+  describe "a delete" do
+    subject { described_class.new("-", 0, "element") }
+    it { should be_deleting }
+    it { should_not be_adding }
+    it { should_not be_unchanged }
+    it { should_not be_changed }
     it { should_not be_finished_a }
     it { should_not be_finished_b }
   end
 
-  describe 'an unchanged' do
-    subject { described_class.new('=', 0, 'element') }
-    it { should_not be_deleting   }
-    it { should_not be_adding     }
-    it { should     be_unchanged  }
-    it { should_not be_changed    }
+  describe "an unchanged" do
+    subject { described_class.new("=", 0, "element") }
+    it { should_not be_deleting }
+    it { should_not be_adding }
+    it { should be_unchanged }
+    it { should_not be_changed }
     it { should_not be_finished_a }
     it { should_not be_finished_b }
   end
 
-  describe 'a changed' do
-    subject { described_class.new('!', 0, 'element') }
-    it { should_not be_deleting   }
-    it { should_not be_adding     }
-    it { should_not be_unchanged  }
-    it { should     be_changed    }
+  describe "a changed" do
+    subject { described_class.new("!", 0, "element") }
+    it { should_not be_deleting }
+    it { should_not be_adding }
+    it { should_not be_unchanged }
+    it { should be_changed }
     it { should_not be_finished_a }
     it { should_not be_finished_b }
   end
 
-  describe 'a finished_a' do
-    subject { described_class.new('>', 0, 'element') }
-    it { should_not be_deleting   }
-    it { should_not be_adding     }
-    it { should_not be_unchanged  }
-    it { should_not be_changed    }
-    it { should     be_finished_a }
+  describe "a finished_a" do
+    subject { described_class.new(">", 0, "element") }
+    it { should_not be_deleting }
+    it { should_not be_adding }
+    it { should_not be_unchanged }
+    it { should_not be_changed }
+    it { should be_finished_a }
     it { should_not be_finished_b }
   end
 
-  describe 'a finished_b' do
-    subject { described_class.new('<', 0, 'element') }
-    it { should_not be_deleting   }
-    it { should_not be_adding     }
-    it { should_not be_unchanged  }
-    it { should_not be_changed    }
+  describe "a finished_b" do
+    subject { described_class.new("<", 0, "element") }
+    it { should_not be_deleting }
+    it { should_not be_adding }
+    it { should_not be_unchanged }
+    it { should_not be_changed }
     it { should_not be_finished_a }
-    it { should     be_finished_b }
+    it { should be_finished_b }
   end
 
-  describe 'as array' do
-    it 'should be converted' do
-      action, position, element = described_class.new('!', 0, 'element')
-      expect(action).to eq '!'
+  describe "as array" do
+    it "should be converted" do
+      action, position, element = described_class.new("!", 0, "element")
+      expect(action).to eq "!"
       expect(position).to eq 0
-      expect(element).to eq 'element'
+      expect(element).to eq "element"
     end
   end
 end
 
 describe Diff::LCS::ContextChange do
-  describe 'as array' do
-    it 'should be converted' do
+  describe "as array" do
+    it "should be converted" do
       action, (old_position, old_element), (new_position, new_element) =
-        described_class.new('!', 1, 'old_element', 2, 'new_element')
+        described_class.new("!", 1, "old_element", 2, "new_element")
 
-      expect(action).to eq '!'
+      expect(action).to eq "!"
       expect(old_position).to eq 1
-      expect(old_element).to eq 'old_element'
+      expect(old_element).to eq "old_element"
       expect(new_position).to eq 2
-      expect(new_element).to eq 'new_element'
+      expect(new_element).to eq "new_element"
     end
   end
 end
diff --git a/spec/diff_spec.rb b/spec/diff_spec.rb
index e7d632a..869f098 100644
--- a/spec/diff_spec.rb
+++ b/spec/diff_spec.rb
@@ -1,28 +1,28 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe Diff::LCS, '.diff' do
+describe Diff::LCS, ".diff" do
   include Diff::LCS::SpecHelper::Matchers
 
-  it 'correctly diffs seq1 to seq2' do
+  it "correctly diffs seq1 to seq2" do
     diff_s1_s2 = Diff::LCS.diff(seq1, seq2)
     expect(change_diff(correct_forward_diff)).to eq(diff_s1_s2)
   end
 
-  it 'correctly diffs seq2 to seq1' do
+  it "correctly diffs seq2 to seq1" do
     diff_s2_s1 = Diff::LCS.diff(seq2, seq1)
     expect(change_diff(correct_backward_diff)).to eq(diff_s2_s1)
   end
 
-  it 'correctly diffs against an empty sequence' do
+  it "correctly diffs against an empty sequence" do
     diff = Diff::LCS.diff(word_sequence, [])
     correct_diff = [
       [
-        ['-', 0, 'abcd'],
-        ['-', 1, 'efgh'],
-        ['-', 2, 'ijkl'],
-        ['-', 3, 'mnopqrstuvwxyz']
+        ["-", 0, "abcd"],
+        ["-", 1, "efgh"],
+        ["-", 2, "ijkl"],
+        ["-", 3, "mnopqrstuvwxyz"]
       ]
     ]
 
@@ -30,22 +30,22 @@ describe Diff::LCS, '.diff' do
 
     diff = Diff::LCS.diff([], word_sequence)
     correct_diff.each do |hunk|
-      hunk.each do |change| change[0] = '+' end
+      hunk.each { |change| change[0] = "+" }
     end
     expect(change_diff(correct_diff)).to eq(diff)
   end
 
   it "correctly diffs 'xx' and 'xaxb'" do
-    left = 'xx'
-    right = 'xaxb'
+    left = "xx"
+    right = "xaxb"
     expect(Diff::LCS.patch(left, Diff::LCS.diff(left, right))).to eq(right)
   end
 
-  it 'returns an empty diff with (hello, hello)' do
+  it "returns an empty diff with (hello, hello)" do
     expect(Diff::LCS.diff(hello, hello)).to be_empty
   end
 
-  it 'returns an empty diff with (hello_ary, hello_ary)' do
+  it "returns an empty diff with (hello_ary, hello_ary)" do
     expect(Diff::LCS.diff(hello_ary, hello_ary)).to be_empty
   end
 end
diff --git a/spec/hunk_spec.rb b/spec/hunk_spec.rb
index b3616bf..c52a6fd 100644
--- a/spec/hunk_spec.rb
+++ b/spec/hunk_spec.rb
@@ -1,18 +1,18 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
 if String.method_defined?(:encoding)
-  require 'diff/lcs/hunk'
+  require "diff/lcs/hunk"
 
   describe Diff::LCS::Hunk do
-    let(:old_data) { ['Tu a un carté avec {count} itéms'.encode('UTF-16LE')] }
-    let(:new_data) { ['Tu a un carte avec {count} items'.encode('UTF-16LE')] }
-    let(:pieces)   { Diff::LCS.diff old_data, new_data }
-    let(:hunk)     { Diff::LCS::Hunk.new(old_data, new_data, pieces[0], 3, 0) }
+    let(:old_data) { ["Tu a un carté avec {count} itéms".encode("UTF-16LE")] }
+    let(:new_data) { ["Tu a un carte avec {count} items".encode("UTF-16LE")] }
+    let(:pieces) { Diff::LCS.diff old_data, new_data }
+    let(:hunk) { Diff::LCS::Hunk.new(old_data, new_data, pieces[0], 3, 0) }
 
-    it 'produces a unified diff from the two pieces' do
-      expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
+    it "produces a unified diff from the two pieces" do
+      expected = <<-EXPECTED.gsub(/^\s+/, "").encode("UTF-16LE").chomp
         @@ -1 +1 @@
         -Tu a un carté avec {count} itéms
         +Tu a un carte avec {count} items
@@ -21,8 +21,8 @@ if String.method_defined?(:encoding)
       expect(hunk.diff(:unified)).to eq(expected)
     end
 
-    it 'produces a unified diff from the two pieces (last entry)' do
-      expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
+    it "produces a unified diff from the two pieces (last entry)" do
+      expected = <<-EXPECTED.gsub(/^\s+/, "").encode("UTF-16LE").chomp
         @@ -1 +1 @@
         -Tu a un carté avec {count} itéms
         +Tu a un carte avec {count} items
@@ -32,8 +32,8 @@ if String.method_defined?(:encoding)
       expect(hunk.diff(:unified, true)).to eq(expected)
     end
 
-    it 'produces a context diff from the two pieces' do
-      expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
+    it "produces a context diff from the two pieces" do
+      expected = <<-EXPECTED.gsub(/^\s+/, "").encode("UTF-16LE").chomp
         ***************
         *** 1 ****
         ! Tu a un carté avec {count} itéms
@@ -44,8 +44,8 @@ if String.method_defined?(:encoding)
       expect(hunk.diff(:context)).to eq(expected)
     end
 
-    it 'produces an old diff from the two pieces' do
-      expected = <<-EXPECTED.gsub(/^ +/, '').encode('UTF-16LE').chomp
+    it "produces an old diff from the two pieces" do
+      expected = <<-EXPECTED.gsub(/^ +/, "").encode("UTF-16LE").chomp
         1c1
         < Tu a un carté avec {count} itéms
         ---
@@ -56,8 +56,8 @@ if String.method_defined?(:encoding)
       expect(hunk.diff(:old)).to eq(expected)
     end
 
-    it 'produces a reverse ed diff from the two pieces' do
-      expected = <<-EXPECTED.gsub(/^ +/, '').encode('UTF-16LE').chomp
+    it "produces a reverse ed diff from the two pieces" do
+      expected = <<-EXPECTED.gsub(/^ +/, "").encode("UTF-16LE").chomp
         c1
         Tu a un carte avec {count} items
         .
@@ -67,11 +67,11 @@ if String.method_defined?(:encoding)
       expect(hunk.diff(:reverse_ed)).to eq(expected)
     end
 
-    context 'with empty first data set' do
+    context "with empty first data set" do
       let(:old_data) { [] }
 
-      it 'produces a unified diff' do
-        expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
+      it "produces a unified diff" do
+        expected = <<-EXPECTED.gsub(/^\s+/, "").encode("UTF-16LE").chomp
           @@ -1 +1,2 @@
           +Tu a un carte avec {count} items
         EXPECTED
diff --git a/spec/issues_spec.rb b/spec/issues_spec.rb
index ad73123..3451d71 100644
--- a/spec/issues_spec.rb
+++ b/spec/issues_spec.rb
@@ -1,73 +1,76 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
-require 'diff/lcs/hunk'
+require "spec_helper"
+require "diff/lcs/hunk"
 
-describe 'Diff::LCS Issues' do
+describe "Diff::LCS Issues" do
   include Diff::LCS::SpecHelper::Matchers
 
-  describe 'issue #1' do
-    shared_examples 'handles simple diffs' do |s1, s2, forward_diff|
+  describe "issue #1" do
+    shared_examples "handles simple diffs" do |s1, s2, forward_diff|
       before do
         @diff_s1_s2 = Diff::LCS.diff(s1, s2)
       end
 
-      it 'creates the correct diff' do
+      it "creates the correct diff" do
         expect(change_diff(forward_diff)).to eq(@diff_s1_s2)
       end
 
-      it 'creates the correct patch s1->s2' do
+      it "creates the correct patch s1->s2" do
         expect(Diff::LCS.patch(s1, @diff_s1_s2)).to eq(s2)
       end
 
-      it 'creates the correct patch s2->s1' do
+      it "creates the correct patch s2->s1" do
         expect(Diff::LCS.patch(s2, @diff_s1_s2)).to eq(s1)
       end
     end
 
-    describe 'string' do
-      it_has_behavior 'handles simple diffs', 'aX', 'bXaX', [
+    describe "string" do
+      it_has_behavior "handles simple diffs", "aX", "bXaX", [
         [
-          ['+', 0, 'b'],
-          ['+', 1, 'X']
+          ["+", 0, "b"],
+          ["+", 1, "X"]
         ]
       ]
-      it_has_behavior 'handles simple diffs', 'bXaX', 'aX', [
+      it_has_behavior "handles simple diffs", "bXaX", "aX", [
         [
-          ['-', 0, 'b'],
-          ['-', 1, 'X']
+          ["-", 0, "b"],
+          ["-", 1, "X"]
         ]
       ]
     end
 
-    describe 'array' do
-      it_has_behavior 'handles simple diffs', %w(a X), %w(b X a X), [
+    describe "array" do
+      it_has_behavior "handles simple diffs", %w[a X], %w[b X a X], [
         [
-          ['+', 0, 'b'],
-          ['+', 1, 'X']
+          ["+", 0, "b"],
+          ["+", 1, "X"]
         ]
       ]
-      it_has_behavior 'handles simple diffs', %w(b X a X), %w(a X), [
+      it_has_behavior "handles simple diffs", %w[b X a X], %w[a X], [
         [
-          ['-', 0, 'b'],
-          ['-', 1, 'X']
+          ["-", 0, "b"],
+          ["-", 1, "X"]
         ]
       ]
     end
   end
 
-  describe 'issue #57' do
-    it 'should fail with a correct error' do
+  describe "issue #57" do
+    it "should fail with a correct error" do
+      # standard:disable Style/HashSyntax
       expect {
-        actual = { :category => 'app.rack.request' }
-        expected = { :category => 'rack.middleware', :title => 'Anonymous Middleware' }
+        actual = {:category => "app.rack.request"}
+        expected = {:category => "rack.middleware", :title => "Anonymous Middleware"}
         expect(actual).to eq(expected)
       }.to raise_error(RSpec::Expectations::ExpectationNotMetError)
+      # standard:enable Style/HashSyntax
     end
   end
 
-  describe 'issue #60' do
-    it 'should produce unified output with correct context' do
+  describe "issue #60" do
+    it "should produce unified output with correct context" do
+      # standard:disable Layout/HeredocIndentation
       old_data = <<-DATA_OLD.strip.split("\n").map(&:chomp)
 {
   "name": "x",
@@ -93,10 +96,11 @@ describe 'Diff::LCS Issues' do
 +  "description": "lo"
  }
       EXPECTED
+      # standard:enable Layout/HeredocIndentation
     end
   end
 
-  describe 'issue #65' do
+  describe "issue #65" do
     def diff_lines(old_lines, new_lines)
       file_length_difference = 0
       previous_hunk = nil
@@ -115,24 +119,25 @@ describe 'Diff::LCS Issues' do
       output.join
     end
 
-    it 'should not misplace the new chunk' do
+    it "should not misplace the new chunk" do
       old_data = [
-        'recipe[a::default]', 'recipe[b::default]', 'recipe[c::default]',
-        'recipe[d::default]', 'recipe[e::default]', 'recipe[f::default]',
-        'recipe[g::default]', 'recipe[h::default]', 'recipe[i::default]',
-        'recipe[j::default]', 'recipe[k::default]', 'recipe[l::default]',
-        'recipe[m::default]', 'recipe[n::default]'
+        "recipe[a::default]", "recipe[b::default]", "recipe[c::default]",
+        "recipe[d::default]", "recipe[e::default]", "recipe[f::default]",
+        "recipe[g::default]", "recipe[h::default]", "recipe[i::default]",
+        "recipe[j::default]", "recipe[k::default]", "recipe[l::default]",
+        "recipe[m::default]", "recipe[n::default]"
       ]
 
       new_data = [
-        'recipe[a::default]', 'recipe[c::default]', 'recipe[d::default]',
-        'recipe[e::default]', 'recipe[f::default]', 'recipe[g::default]',
-        'recipe[h::default]', 'recipe[i::default]', 'recipe[j::default]',
-        'recipe[k::default]', 'recipe[l::default]', 'recipe[m::default]',
-        'recipe[n::default]', 'recipe[o::new]', 'recipe[p::new]',
-        'recipe[q::new]', 'recipe[r::new]'
+        "recipe[a::default]", "recipe[c::default]", "recipe[d::default]",
+        "recipe[e::default]", "recipe[f::default]", "recipe[g::default]",
+        "recipe[h::default]", "recipe[i::default]", "recipe[j::default]",
+        "recipe[k::default]", "recipe[l::default]", "recipe[m::default]",
+        "recipe[n::default]", "recipe[o::new]", "recipe[p::new]",
+        "recipe[q::new]", "recipe[r::new]"
       ]
 
+      # standard:disable Layout/HeredocIndentation
       expect(diff_lines(old_data, new_data)).to eq(<<-EODIFF)
 @@ -1,5 +1,4 @@
  recipe[a::default]
@@ -149,6 +154,7 @@ describe 'Diff::LCS Issues' do
 +recipe[q::new]
 +recipe[r::new]
       EODIFF
+      # standard:enable Layout/HeredocIndentation
     end
   end
 end
diff --git a/spec/lcs_spec.rb b/spec/lcs_spec.rb
index 94428fd..c17f22f 100644
--- a/spec/lcs_spec.rb
+++ b/spec/lcs_spec.rb
@@ -1,11 +1,11 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe Diff::LCS::Internals, '.lcs' do
+describe Diff::LCS::Internals, ".lcs" do
   include Diff::LCS::SpecHelper::Matchers
 
-  it 'returns a meaningful LCS array with (seq1, seq2)' do
+  it "returns a meaningful LCS array with (seq1, seq2)" do
     res = Diff::LCS::Internals.lcs(seq1, seq2)
     # The result of the LCS (less the +nil+ values) must be as long as the
     # correct result.
@@ -20,37 +20,37 @@ describe Diff::LCS::Internals, '.lcs' do
     expect(x_seq2).to eq(correct_lcs)
   end
 
-  it 'returns all indexes with (hello, hello)' do
+  it "returns all indexes with (hello, hello)" do
     expect(Diff::LCS::Internals.lcs(hello, hello)).to \
       eq((0...hello.size).to_a)
   end
 
-  it 'returns all indexes with (hello_ary, hello_ary)' do
+  it "returns all indexes with (hello_ary, hello_ary)" do
     expect(Diff::LCS::Internals.lcs(hello_ary, hello_ary)).to \
       eq((0...hello_ary.size).to_a)
   end
 end
 
-describe Diff::LCS, '.LCS' do
+describe Diff::LCS, ".LCS" do
   include Diff::LCS::SpecHelper::Matchers
 
-  it 'returns the correct compacted values from Diff::LCS.LCS' do
+  it "returns the correct compacted values from Diff::LCS.LCS" do
     res = Diff::LCS.LCS(seq1, seq2)
     expect(res).to eq(correct_lcs)
     expect(res.compact).to eq(res)
   end
 
-  it 'is transitive' do
+  it "is transitive" do
     res = Diff::LCS.LCS(seq2, seq1)
     expect(res).to eq(correct_lcs)
     expect(res.compact).to eq(res)
   end
 
-  it 'returns %W(h e l l o) with (hello, hello)' do
-    expect(Diff::LCS.LCS(hello, hello)).to eq(hello.split(//))
+  it "returns %W(h e l l o) with (hello, hello)" do
+    expect(Diff::LCS.LCS(hello, hello)).to eq(hello.chars)
   end
 
-  it 'returns hello_ary with (hello_ary, hello_ary)' do
+  it "returns hello_ary with (hello_ary, hello_ary)" do
     expect(Diff::LCS.LCS(hello_ary, hello_ary)).to eq(hello_ary)
   end
 end
diff --git a/spec/ldiff_spec.rb b/spec/ldiff_spec.rb
index a2468f8..cf89ada 100644
--- a/spec/ldiff_spec.rb
+++ b/spec/ldiff_spec.rb
@@ -1,29 +1,31 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-RSpec.describe 'bin/ldiff' do
+RSpec.describe "bin/ldiff" do
   include CaptureSubprocessIO
 
+  # standard:disable Style/HashSyntax
   fixtures = [
-    { :name => 'output.diff', :left => 'aX', :right => 'bXaX' },
-    { :name => 'output.diff.chef', :left => 'old-chef', :right => 'new-chef' },
-    { :name => 'output.diff.chef2', :left => 'old-chef2', :right => 'new-chef2' }
-  ].product([nil, '-e', '-f', '-c', '-u']).map { |(fixture, flag)|
+    {:name => "output.diff", :left => "aX", :right => "bXaX"},
+    {:name => "output.diff.chef", :left => "old-chef", :right => "new-chef"},
+    {:name => "output.diff.chef2", :left => "old-chef2", :right => "new-chef2"}
+  ].product([nil, "-e", "-f", "-c", "-u"]).map { |(fixture, flag)|
     fixture = fixture.dup
     fixture[:flag] = flag
     fixture
   }
+  # standard:enable Style/HashSyntax
 
   def self.test_ldiff(fixture)
     desc = [
       fixture[:flag],
       "spec/fixtures/#{fixture[:left]}",
       "spec/fixtures/#{fixture[:right]}",
-      '#',
-      '=>',
+      "#",
+      "=>",
       "spec/fixtures/ldiff/#{fixture[:name]}#{fixture[:flag]}"
-    ].join(' ')
+    ].join(" ")
 
     it desc do
       expect(run_ldiff(fixture)).to eq(read_fixture(fixture))
@@ -45,7 +47,7 @@ RSpec.describe 'bin/ldiff' do
   def clean_data(data, flag)
     data =
       case flag
-      when '-c', '-u'
+      when "-c", "-u"
         clean_output_timestamp(data)
       else
         data
@@ -80,7 +82,7 @@ RSpec.describe 'bin/ldiff' do
       system("ruby -Ilib bin/ldiff #{flag} spec/fixtures/#{left} spec/fixtures/#{right}")
     end
 
-    expect(stderr).to be_empty if RUBY_VERSION >= '1.9'
+    expect(stderr).to be_empty if RUBY_VERSION >= "1.9"
     expect(stdout).not_to be_empty
     clean_data(stdout, flag)
   end
diff --git a/spec/patch_spec.rb b/spec/patch_spec.rb
index 11b0981..6b9bf28 100644
--- a/spec/patch_spec.rb
+++ b/spec/patch_spec.rb
@@ -1,54 +1,54 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe 'Diff::LCS.patch' do
+describe "Diff::LCS.patch" do
   include Diff::LCS::SpecHelper::Matchers
 
-  shared_examples 'patch sequences correctly' do
-    it 'correctly patches left-to-right (patch autodiscovery)' do
+  shared_examples "patch sequences correctly" do
+    it "correctly patches left-to-right (patch autodiscovery)" do
       expect(Diff::LCS.patch(s1, patch_set)).to eq(s2)
     end
 
-    it 'correctly patches left-to-right (explicit patch)' do
+    it "correctly patches left-to-right (explicit patch)" do
       expect(Diff::LCS.patch(s1, patch_set, :patch)).to eq(s2)
       expect(Diff::LCS.patch!(s1, patch_set)).to eq(s2)
     end
 
-    it 'correctly patches right-to-left (unpatch autodiscovery)' do
+    it "correctly patches right-to-left (unpatch autodiscovery)" do
       expect(Diff::LCS.patch(s2, patch_set)).to eq(s1)
     end
 
-    it 'correctly patches right-to-left (explicit unpatch)' do
+    it "correctly patches right-to-left (explicit unpatch)" do
       expect(Diff::LCS.patch(s2, patch_set, :unpatch)).to eq(s1)
       expect(Diff::LCS.unpatch!(s2, patch_set)).to eq(s1)
     end
   end
 
-  describe 'using a Diff::LCS.diff patchset' do
-    describe 'an empty patchset returns the source' do
-      it 'works on a string (hello)' do
+  describe "using a Diff::LCS.diff patchset" do
+    describe "an empty patchset returns the source" do
+      it "works on a string (hello)" do
         diff = Diff::LCS.diff(hello, hello)
         expect(Diff::LCS.patch(hello, diff)).to eq(hello)
       end
 
-      it 'works on an array %W(h e l l o)' do
+      it "works on an array %W(h e l l o)" do
         diff = Diff::LCS.diff(hello_ary, hello_ary)
         expect(Diff::LCS.patch(hello_ary, diff)).to eq(hello_ary)
       end
     end
 
-    describe 'with default diff callbacks (DiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with default diff callbacks (DiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) { Diff::LCS.diff(seq1, seq2) }
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) { Diff::LCS.diff(seq2, seq1) }
@@ -56,9 +56,9 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'with context diff callbacks (ContextDiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with context diff callbacks (ContextDiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) {
@@ -67,8 +67,8 @@ describe 'Diff::LCS.patch' do
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) {
@@ -78,9 +78,9 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'with sdiff callbacks (SDiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with sdiff callbacks (SDiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) {
@@ -89,8 +89,8 @@ describe 'Diff::LCS.patch' do
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) {
@@ -101,20 +101,20 @@ describe 'Diff::LCS.patch' do
     end
   end
 
-  describe 'using a Diff::LCS.sdiff patchset' do
-    describe 'an empty patchset returns the source' do
-      it 'works on a string (hello)' do
+  describe "using a Diff::LCS.sdiff patchset" do
+    describe "an empty patchset returns the source" do
+      it "works on a string (hello)" do
         expect(Diff::LCS.patch(hello, Diff::LCS.sdiff(hello, hello))).to eq(hello)
       end
 
-      it 'works on an array %W(h e l l o)' do
+      it "works on an array %W(h e l l o)" do
         expect(Diff::LCS.patch(hello_ary, Diff::LCS.sdiff(hello_ary, hello_ary))).to eq(hello_ary)
       end
     end
 
-    describe 'with default diff callbacks (DiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with default diff callbacks (DiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) {
@@ -123,8 +123,8 @@ describe 'Diff::LCS.patch' do
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) {
@@ -134,9 +134,9 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'with context diff callbacks (DiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with context diff callbacks (DiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) {
@@ -145,8 +145,8 @@ describe 'Diff::LCS.patch' do
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) {
@@ -156,17 +156,17 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'with sdiff callbacks (SDiffCallbacks)' do
-      describe 'forward (s1 -> s2)' do
-        it_has_behavior 'patch sequences correctly' do
+    describe "with sdiff callbacks (SDiffCallbacks)" do
+      describe "forward (s1 -> s2)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq1 }
           let(:s2) { seq2 }
           let(:patch_set) { Diff::LCS.sdiff(seq1, seq2) }
         end
       end
 
-      describe 'reverse (s2 -> s1)' do
-        it_has_behavior 'patch sequences correctly' do
+      describe "reverse (s2 -> s1)" do
+        it_has_behavior "patch sequences correctly" do
           let(:s1) { seq2 }
           let(:s2) { seq1 }
           let(:patch_set) { Diff::LCS.sdiff(seq2, seq1) }
@@ -179,43 +179,43 @@ describe 'Diff::LCS.patch' do
   # to s2 patches"), this cannot use the "patch sequences correctly" shared
   # set. Once the bug in autodiscovery is fixed, this can be converted as
   # above.
-  describe 'fix bug 891: patchsets do not contain the last equal part' do
+  describe "fix bug 891: patchsets do not contain the last equal part" do
     before :each do
-      @s1 = %w(a b c d   e f g h i j k) # rubocop:disable Layout/SpaceInsideArrayPercentLiteral
-      @s2 = %w(a b c d D e f g h i j k)
+      @s1 = %w[a b c d   e f g h i j k] # rubocop:disable Layout/SpaceInsideArrayPercentLiteral
+      @s2 = %w[a b c d D e f g h i j k]
     end
 
-    describe 'using Diff::LCS.diff with default diff callbacks' do
+    describe "using Diff::LCS.diff with default diff callbacks" do
       before :each do
         @patch_set_s1_s2 = Diff::LCS.diff(@s1, @s2)
         @patch_set_s2_s1 = Diff::LCS.diff(@s2, @s1)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
@@ -223,37 +223,37 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'using Diff::LCS.diff with context diff callbacks' do
+    describe "using Diff::LCS.diff with context diff callbacks" do
       before :each do
         @patch_set_s1_s2 = Diff::LCS.diff(@s1, @s2, Diff::LCS::ContextDiffCallbacks)
         @patch_set_s2_s1 = Diff::LCS.diff(@s2, @s1, Diff::LCS::ContextDiffCallbacks)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
@@ -261,37 +261,37 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'using Diff::LCS.diff with sdiff callbacks' do
+    describe "using Diff::LCS.diff with sdiff callbacks" do
       before(:each) do
         @patch_set_s1_s2 = Diff::LCS.diff(@s1, @s2, Diff::LCS::SDiffCallbacks)
         @patch_set_s2_s1 = Diff::LCS.diff(@s2, @s1, Diff::LCS::SDiffCallbacks)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
@@ -299,37 +299,37 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'using Diff::LCS.sdiff with default sdiff callbacks' do
+    describe "using Diff::LCS.sdiff with default sdiff callbacks" do
       before(:each) do
         @patch_set_s1_s2 = Diff::LCS.sdiff(@s1, @s2)
         @patch_set_s2_s1 = Diff::LCS.sdiff(@s2, @s1)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
@@ -337,37 +337,37 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'using Diff::LCS.sdiff with context diff callbacks' do
+    describe "using Diff::LCS.sdiff with context diff callbacks" do
       before(:each) do
         @patch_set_s1_s2 = Diff::LCS.sdiff(@s1, @s2, Diff::LCS::ContextDiffCallbacks)
         @patch_set_s2_s1 = Diff::LCS.sdiff(@s2, @s1, Diff::LCS::ContextDiffCallbacks)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
@@ -375,37 +375,37 @@ describe 'Diff::LCS.patch' do
       end
     end
 
-    describe 'using Diff::LCS.sdiff with default diff callbacks' do
+    describe "using Diff::LCS.sdiff with default diff callbacks" do
       before(:each) do
         @patch_set_s1_s2 = Diff::LCS.sdiff(@s1, @s2, Diff::LCS::DiffCallbacks)
         @patch_set_s2_s1 = Diff::LCS.sdiff(@s2, @s1, Diff::LCS::DiffCallbacks)
       end
 
-      it 'autodiscovers s1 to s2 patches' do
+      it "autodiscovers s1 to s2 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s1_s2)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 patches' do
+      it "autodiscovers s2 to s1 patches" do
         expect do
           expect(Diff::LCS.patch(@s1, @patch_set_s2_s1)).to eq(@s2)
         end.to_not raise_error
       end
 
-      it 'autodiscovers s2 to s1 the left-to-right patches' do
+      it "autodiscovers s2 to s1 the left-to-right patches" do
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1)).to eq(@s1)
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2)).to eq(@s1)
       end
 
-      it 'correctly patches left-to-right (explicit patch)' do
+      it "correctly patches left-to-right (explicit patch)" do
         expect(Diff::LCS.patch(@s1, @patch_set_s1_s2, :patch)).to eq(@s2)
         expect(Diff::LCS.patch(@s2, @patch_set_s2_s1, :patch)).to eq(@s1)
         expect(Diff::LCS.patch!(@s1, @patch_set_s1_s2)).to eq(@s2)
         expect(Diff::LCS.patch!(@s2, @patch_set_s2_s1)).to eq(@s1)
       end
 
-      it 'correctly patches right-to-left (explicit unpatch)' do
+      it "correctly patches right-to-left (explicit unpatch)" do
         expect(Diff::LCS.patch(@s2, @patch_set_s1_s2, :unpatch)).to eq(@s1)
         expect(Diff::LCS.patch(@s1, @patch_set_s2_s1, :unpatch)).to eq(@s2)
         expect(Diff::LCS.unpatch!(@s2, @patch_set_s1_s2)).to eq(@s1)
diff --git a/spec/sdiff_spec.rb b/spec/sdiff_spec.rb
index 06d39d6..aded301 100644
--- a/spec/sdiff_spec.rb
+++ b/spec/sdiff_spec.rb
@@ -1,214 +1,216 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe 'Diff::LCS.sdiff' do
+describe "Diff::LCS.sdiff" do
   include Diff::LCS::SpecHelper::Matchers
 
-  shared_examples 'compare sequences correctly' do
-    it 'compares s1 -> s2 correctly' do
+  shared_examples "compare sequences correctly" do
+    it "compares s1 -> s2 correctly" do
       expect(Diff::LCS.sdiff(s1, s2)).to eq(context_diff(result))
     end
 
-    it 'compares s2 -> s1 correctly' do
+    it "compares s2 -> s1 correctly" do
       expect(Diff::LCS.sdiff(s2, s1)).to eq(context_diff(reverse_sdiff(result)))
     end
   end
 
-  describe 'using seq1 & seq2' do
+  describe "using seq1 & seq2" do
     let(:s1) { seq1 }
     let(:s2) { seq2 }
     let(:result) { correct_forward_sdiff }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(abc def yyy xxx ghi jkl) & %w(abc dxf xxx ghi jkl)' do
-    let(:s1) { %w(abc def yyy xxx ghi jkl) }
-    let(:s2) { %w(abc dxf xxx ghi jkl) }
+  describe "using %w(abc def yyy xxx ghi jkl) & %w(abc dxf xxx ghi jkl)" do
+    let(:s1) { %w[abc def yyy xxx ghi jkl] }
+    let(:s2) { %w[abc dxf xxx ghi jkl] }
     let(:result) {
+      # standard:disable Layout/ExtraSpacing
       [
-        ['=', [0, 'abc'], [0, 'abc']],
-        ['!', [1, 'def'], [1, 'dxf']],
-        ['-', [2, 'yyy'], [2,  nil]],
-        ['=', [3, 'xxx'], [2, 'xxx']],
-        ['=', [4, 'ghi'], [3, 'ghi']],
-        ['=', [5, 'jkl'], [4, 'jkl']]
+        ["=", [0, "abc"], [0, "abc"]],
+        ["!", [1, "def"], [1, "dxf"]],
+        ["-", [2, "yyy"], [2,  nil]],
+        ["=", [3, "xxx"], [2, "xxx"]],
+        ["=", [4, "ghi"], [3, "ghi"]],
+        ["=", [5, "jkl"], [4, "jkl"]]
       ]
+      # standard:enable Layout/ExtraSpacing
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a b c d e) & %w(a e)' do
-    let(:s1) { %w(a b c d e) }
-    let(:s2) { %w(a e) }
+  describe "using %w(a b c d e) & %w(a e)" do
+    let(:s1) { %w[a b c d e] }
+    let(:s2) { %w[a e] }
     let(:result) {
       [
-        ['=', [0, 'a'], [0, 'a']],
-        ['-', [1, 'b'], [1, nil]],
-        ['-', [2, 'c'], [1, nil]],
-        ['-', [3, 'd'], [1, nil]],
-        ['=', [4, 'e'], [1, 'e']]
+        ["=", [0, "a"], [0, "a"]],
+        ["-", [1, "b"], [1, nil]],
+        ["-", [2, "c"], [1, nil]],
+        ["-", [3, "d"], [1, nil]],
+        ["=", [4, "e"], [1, "e"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a e) & %w(a b c d e)' do
-    let(:s1) { %w(a e) }
-    let(:s2) { %w(a b c d e) }
+  describe "using %w(a e) & %w(a b c d e)" do
+    let(:s1) { %w[a e] }
+    let(:s2) { %w[a b c d e] }
     let(:result) {
       [
-        ['=', [0, 'a'], [0, 'a']],
-        ['+', [1, nil], [1, 'b']],
-        ['+', [1, nil], [2, 'c']],
-        ['+', [1, nil], [3, 'd']],
-        ['=', [1, 'e'], [4, 'e']]
+        ["=", [0, "a"], [0, "a"]],
+        ["+", [1, nil], [1, "b"]],
+        ["+", [1, nil], [2, "c"]],
+        ["+", [1, nil], [3, "d"]],
+        ["=", [1, "e"], [4, "e"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(v x a e) & %w(w y a b c d e)' do
-    let(:s1) { %w(v x a e) }
-    let(:s2) { %w(w y a b c d e) }
+  describe "using %w(v x a e) & %w(w y a b c d e)" do
+    let(:s1) { %w[v x a e] }
+    let(:s2) { %w[w y a b c d e] }
     let(:result) {
       [
-        ['!', [0, 'v'], [0, 'w']],
-        ['!', [1, 'x'], [1, 'y']],
-        ['=', [2, 'a'], [2, 'a']],
-        ['+', [3, nil], [3, 'b']],
-        ['+', [3, nil], [4, 'c']],
-        ['+', [3, nil], [5, 'd']],
-        ['=', [3, 'e'], [6, 'e']]
+        ["!", [0, "v"], [0, "w"]],
+        ["!", [1, "x"], [1, "y"]],
+        ["=", [2, "a"], [2, "a"]],
+        ["+", [3, nil], [3, "b"]],
+        ["+", [3, nil], [4, "c"]],
+        ["+", [3, nil], [5, "d"]],
+        ["=", [3, "e"], [6, "e"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(x a e) & %w(a b c d e)' do
-    let(:s1) { %w(x a e) }
-    let(:s2) { %w(a b c d e) }
+  describe "using %w(x a e) & %w(a b c d e)" do
+    let(:s1) { %w[x a e] }
+    let(:s2) { %w[a b c d e] }
     let(:result) {
       [
-        ['-', [0, 'x'], [0, nil]],
-        ['=', [1, 'a'], [0, 'a']],
-        ['+', [2, nil], [1, 'b']],
-        ['+', [2, nil], [2, 'c']],
-        ['+', [2, nil], [3, 'd']],
-        ['=', [2, 'e'], [4, 'e']]
+        ["-", [0, "x"], [0, nil]],
+        ["=", [1, "a"], [0, "a"]],
+        ["+", [2, nil], [1, "b"]],
+        ["+", [2, nil], [2, "c"]],
+        ["+", [2, nil], [3, "d"]],
+        ["=", [2, "e"], [4, "e"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a e) & %w(x a b c d e)' do
-    let(:s1) { %w(a e) }
-    let(:s2) { %w(x a b c d e) }
+  describe "using %w(a e) & %w(x a b c d e)" do
+    let(:s1) { %w[a e] }
+    let(:s2) { %w[x a b c d e] }
     let(:result) {
       [
-        ['+', [0, nil], [0, 'x']],
-        ['=', [0, 'a'], [1, 'a']],
-        ['+', [1, nil], [2, 'b']],
-        ['+', [1, nil], [3, 'c']],
-        ['+', [1, nil], [4, 'd']],
-        ['=', [1, 'e'], [5, 'e']]
+        ["+", [0, nil], [0, "x"]],
+        ["=", [0, "a"], [1, "a"]],
+        ["+", [1, nil], [2, "b"]],
+        ["+", [1, nil], [3, "c"]],
+        ["+", [1, nil], [4, "d"]],
+        ["=", [1, "e"], [5, "e"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a e v) & %w(x a b c d e w x)' do
-    let(:s1) { %w(a e v) }
-    let(:s2) { %w(x a b c d e w x) }
+  describe "using %w(a e v) & %w(x a b c d e w x)" do
+    let(:s1) { %w[a e v] }
+    let(:s2) { %w[x a b c d e w x] }
     let(:result) {
       [
-        ['+', [0, nil], [0, 'x']],
-        ['=', [0, 'a'], [1, 'a']],
-        ['+', [1, nil], [2, 'b']],
-        ['+', [1, nil], [3, 'c']],
-        ['+', [1, nil], [4, 'd']],
-        ['=', [1, 'e'], [5, 'e']],
-        ['!', [2, 'v'], [6, 'w']],
-        ['+', [3, nil], [7, 'x']]
+        ["+", [0, nil], [0, "x"]],
+        ["=", [0, "a"], [1, "a"]],
+        ["+", [1, nil], [2, "b"]],
+        ["+", [1, nil], [3, "c"]],
+        ["+", [1, nil], [4, "d"]],
+        ["=", [1, "e"], [5, "e"]],
+        ["!", [2, "v"], [6, "w"]],
+        ["+", [3, nil], [7, "x"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w() & %w(a b c)' do
-    let(:s1) { %w() }
-    let(:s2) { %w(a b c) }
+  describe "using %w() & %w(a b c)" do
+    let(:s1) { %w[] }
+    let(:s2) { %w[a b c] }
     let(:result) {
       [
-        ['+', [0, nil], [0, 'a']],
-        ['+', [0, nil], [1, 'b']],
-        ['+', [0, nil], [2, 'c']]
+        ["+", [0, nil], [0, "a"]],
+        ["+", [0, nil], [1, "b"]],
+        ["+", [0, nil], [2, "c"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a b c) & %w(1)' do
-    let(:s1) { %w(a b c) }
-    let(:s2) { %w(1) }
+  describe "using %w(a b c) & %w(1)" do
+    let(:s1) { %w[a b c] }
+    let(:s2) { %w[1] }
     let(:result) {
       [
-        ['!', [0, 'a'], [0, '1']],
-        ['-', [1, 'b'], [1, nil]],
-        ['-', [2, 'c'], [1, nil]]
+        ["!", [0, "a"], [0, "1"]],
+        ["-", [1, "b"], [1, nil]],
+        ["-", [2, "c"], [1, nil]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(a b c) & %w(c)' do
-    let(:s1) { %w(a b c) }
-    let(:s2) { %w(c) }
+  describe "using %w(a b c) & %w(c)" do
+    let(:s1) { %w[a b c] }
+    let(:s2) { %w[c] }
     let(:result) {
       [
-        ['-', [0, 'a'], [0, nil]],
-        ['-', [1, 'b'], [0, nil]],
-        ['=', [2, 'c'], [0, 'c']]
+        ["-", [0, "a"], [0, nil]],
+        ["-", [1, "b"], [0, nil]],
+        ["=", [2, "c"], [0, "c"]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using %w(abcd efgh ijkl mnop) & []' do
-    let(:s1) { %w(abcd efgh ijkl mnop) }
+  describe "using %w(abcd efgh ijkl mnop) & []" do
+    let(:s1) { %w[abcd efgh ijkl mnop] }
     let(:s2) { [] }
     let(:result) {
       [
-        ['-', [0, 'abcd'], [0, nil]],
-        ['-', [1, 'efgh'], [0, nil]],
-        ['-', [2, 'ijkl'], [0, nil]],
-        ['-', [3, 'mnop'], [0, nil]]
+        ["-", [0, "abcd"], [0, nil]],
+        ["-", [1, "efgh"], [0, nil]],
+        ["-", [2, "ijkl"], [0, nil]],
+        ["-", [3, "mnop"], [0, nil]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 
-  describe 'using [[1,2]] & []' do
+  describe "using [[1,2]] & []" do
     let(:s1) { [[1, 2]] }
     let(:s2) { [] }
     let(:result) {
       [
-        ['-', [0, [1, 2]], [0, nil]]
+        ["-", [0, [1, 2]], [0, nil]]
       ]
     }
 
-    it_has_behavior 'compare sequences correctly'
+    it_has_behavior "compare sequences correctly"
   end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 41e1f8e..6993912 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,12 +1,12 @@
 # frozen_string_literal: true
 
-require 'rubygems'
-require 'pathname'
+require "rubygems"
+require "pathname"
 
-require 'psych' if RUBY_VERSION >= '1.9'
+require "psych" if RUBY_VERSION >= "1.9"
 
-if ENV['COVERAGE']
-  require 'simplecov'
+if ENV["COVERAGE"]
+  require "simplecov"
 
   def require_do(resource)
     require resource
@@ -17,13 +17,13 @@ if ENV['COVERAGE']
 
   formatters = [SimpleCov::Formatter::HTMLFormatter]
 
-  require_do('simplecov-rcov') {
+  require_do("simplecov-rcov") {
     formatters << SimpleCov::Formatter::RcovFormatter
   }
-  require_do('simplecov-vim/formatter') {
+  require_do("simplecov-vim/formatter") {
     formatters << SimpleCov::Formatter::VimFormatter
   }
-  require_do('simplecov-sublime-ruby-coverage') {
+  require_do("simplecov-sublime-ruby-coverage") {
     formatters << SimpleCov::Formatter::SublimeRubyCoverageFormatter
   }
 
@@ -32,11 +32,11 @@ if ENV['COVERAGE']
   end
 end
 
-file   = Pathname.new(__FILE__).expand_path
-path   = file.parent
+file = Pathname.new(__FILE__).expand_path
+path = file.parent
 parent = path.parent
 
-$:.unshift parent.join('lib')
+$:.unshift parent.join("lib")
 
 module CaptureSubprocessIO
   def _synchronize
@@ -48,9 +48,9 @@ module CaptureSubprocessIO
   end
 
   def _capture_subprocess_io
-    require 'tempfile'
+    require "tempfile"
 
-    captured_stdout, captured_stderr = Tempfile.new('out'), Tempfile.new('err')
+    captured_stdout, captured_stderr = Tempfile.new("out"), Tempfile.new("err")
 
     orig_stdout, orig_stderr = $stdout.dup, $stderr.dup
     $stdout.reopen captured_stdout
@@ -71,62 +71,63 @@ module CaptureSubprocessIO
   private :_capture_subprocess_io
 end
 
-require 'diff-lcs'
+require "diff-lcs"
 
 module Diff::LCS::SpecHelper
   def hello
-    'hello'
+    "hello"
   end
 
   def hello_ary
-    %w(h e l l o)
+    %w[h e l l o]
   end
 
   def seq1
-    %w(a b c e h j l m n p)
+    %w[a b c e h j l m n p]
   end
 
   def skipped_seq1
-    %w(a h n p)
+    %w[a h n p]
   end
 
   def seq2
-    %w(b c d e f j k l m r s t)
+    %w[b c d e f j k l m r s t]
   end
 
   def skipped_seq2
-    %w(d f k r s t)
+    %w[d f k r s t]
   end
 
   def word_sequence
-    %w(abcd efgh ijkl mnopqrstuvwxyz)
+    %w[abcd efgh ijkl mnopqrstuvwxyz]
   end
 
   def correct_lcs
-    %w(b c e j l m)
+    %w[b c e j l m]
   end
 
+  # standard:disable Layout/ExtraSpacing
   def correct_forward_diff
     [
       [
-        ['-',  0, 'a']
+        ["-",  0, "a"]
       ],
       [
-        ['+',  2, 'd']
+        ["+",  2, "d"]
       ],
       [
-        ['-',  4, 'h'],
-        ['+',  4, 'f']
+        ["-",  4, "h"],
+        ["+",  4, "f"]
       ],
       [
-        ['+',  6, 'k']
+        ["+",  6, "k"]
       ],
       [
-        ['-',  8, 'n'],
-        ['+',  9, 'r'],
-        ['-',  9, 'p'],
-        ['+', 10, 's'],
-        ['+', 11, 't']
+        ["-",  8, "n"],
+        ["+",  9, "r"],
+        ["-",  9, "p"],
+        ["+", 10, "s"],
+        ["+", 11, "t"]
       ]
     ]
   end
@@ -134,52 +135,53 @@ module Diff::LCS::SpecHelper
   def correct_backward_diff
     [
       [
-        ['+',  0, 'a']
+        ["+",  0, "a"]
       ],
       [
-        ['-',  2, 'd']
+        ["-",  2, "d"]
       ],
       [
-        ['-',  4, 'f'],
-        ['+',  4, 'h']
+        ["-",  4, "f"],
+        ["+",  4, "h"]
       ],
       [
-        ['-',  6, 'k']
+        ["-",  6, "k"]
       ],
       [
-        ['-',  9, 'r'],
-        ['+',  8, 'n'],
-        ['-', 10, 's'],
-        ['+',  9, 'p'],
-        ['-', 11, 't']
+        ["-",  9, "r"],
+        ["+",  8, "n"],
+        ["-", 10, "s"],
+        ["+",  9, "p"],
+        ["-", 11, "t"]
       ]
     ]
   end
 
   def correct_forward_sdiff
     [
-      ['-', [0, 'a'], [0, nil]],
-      ['=', [1, 'b'], [0, 'b']],
-      ['=', [2, 'c'], [1, 'c']],
-      ['+', [3, nil], [2, 'd']],
-      ['=', [3, 'e'], [3, 'e']],
-      ['!', [4, 'h'], [4, 'f']],
-      ['=', [5, 'j'], [5, 'j']],
-      ['+', [6, nil], [6, 'k']],
-      ['=', [6, 'l'], [7, 'l']],
-      ['=', [7, 'm'], [8, 'm']],
-      ['!', [8, 'n'], [9, 'r']],
-      ['!', [9, 'p'], [10, 's']],
-      ['+', [10, nil], [11, 't']]
+      ["-", [0, "a"], [0, nil]],
+      ["=", [1, "b"], [0, "b"]],
+      ["=", [2, "c"], [1, "c"]],
+      ["+", [3, nil], [2, "d"]],
+      ["=", [3, "e"], [3, "e"]],
+      ["!", [4, "h"], [4, "f"]],
+      ["=", [5, "j"], [5, "j"]],
+      ["+", [6, nil], [6, "k"]],
+      ["=", [6, "l"], [7, "l"]],
+      ["=", [7, "m"], [8, "m"]],
+      ["!", [8, "n"], [9, "r"]],
+      ["!", [9, "p"], [10, "s"]],
+      ["+", [10, nil], [11, "t"]]
     ]
   end
+  # standard:enable Layout/ExtraSpacing
 
   def reverse_sdiff(forward_sdiff)
     forward_sdiff.map { |line|
       line[1], line[2] = line[2], line[1]
       case line[0]
-      when '-' then line[0] = '+'
-      when '+' then line[0] = '-'
+      when "-" then line[0] = "+"
+      when "+" then line[0] = "-"
       end
       line
     }
@@ -195,8 +197,8 @@ module Diff::LCS::SpecHelper
 
   def format_diffs(diffs)
     diffs.map { |e|
-      if e.kind_of?(Array)
-        e.map { |f| f.to_a.join }.join(', ')
+      if e.is_a?(Array)
+        e.map { |f| f.to_a.join }.join(", ")
       else
         e.to_a.join
       end
@@ -224,10 +226,10 @@ module Diff::LCS::SpecHelper
     change_result.each do |line|
       line = [line[0], line[2], line[1]]
       case line[0]
-      when '<'
-        line[0] = '>'
-      when '>'
-        line[0] = '<'
+      when "<"
+        line[0] = ">"
+      when ">"
+        line[0] = "<"
       end
       new_result << line
     end
@@ -238,9 +240,9 @@ module Diff::LCS::SpecHelper
     new_result = []
     change_result.each do |line|
       case line[0]
-      when '!'
-        new_result << ['<', line[1], line[2]]
-        new_result << ['>', line[1] + 1, line[2]]
+      when "!"
+        new_result << ["<", line[1], line[2]]
+        new_result << [">", line[1] + 1, line[2]]
       else
         new_result << line
       end
@@ -317,19 +319,19 @@ module Diff::LCS::SpecHelper
       end
 
       def match(event)
-        @result << ['=', event.old_position, event.new_position]
+        @result << ["=", event.old_position, event.new_position]
       end
 
       def discard_a(event)
-        @result << ['<', event.old_position, event.new_position]
+        @result << ["<", event.old_position, event.new_position]
       end
 
       def discard_b(event)
-        @result << ['>', event.old_position, event.new_position]
+        @result << [">", event.old_position, event.new_position]
       end
 
       def change(event)
-        @result << ['!', event.old_position, event.new_position]
+        @result << ["!", event.old_position, event.new_position]
       end
     end
     cb.reset
@@ -355,9 +357,7 @@ module Diff::LCS::SpecHelper
 
     matcher :correctly_map_sequence do |s1|
       match do |actual|
-        actual.each_with_index { |ee, ii|
-          expect(ee).to be_nil_or_match_values(ii, s1, @s2)
-        }
+        actual.each_index { |ii| expect(actual[ii]).to be_nil_or_match_values(ii, s1, @s2) }
       end
 
       chain :to_other_sequence do |s2|
@@ -369,6 +369,8 @@ end
 
 RSpec.configure do |conf|
   conf.include Diff::LCS::SpecHelper
-  conf.alias_it_should_behave_like_to :it_has_behavior, 'has behavior:'
+  conf.alias_it_should_behave_like_to :it_has_behavior, "has behavior:"
+  # standard:disable Style/HashSyntax
   conf.filter_run_excluding :broken => true
+  # standard:enable Style/HashSyntax
 end
diff --git a/spec/traverse_balanced_spec.rb b/spec/traverse_balanced_spec.rb
index 9ee68ea..3a3f677 100644
--- a/spec/traverse_balanced_spec.rb
+++ b/spec/traverse_balanced_spec.rb
@@ -1,310 +1,312 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe 'Diff::LCS.traverse_balanced' do
+describe "Diff::LCS.traverse_balanced" do
   include Diff::LCS::SpecHelper::Matchers
 
-  shared_examples 'with a #change callback' do |s1, s2, result|
-    it 'traverses s1 -> s2 correctly' do
+  shared_examples "with a #change callback" do |s1, s2, result|
+    it "traverses s1 -> s2 correctly" do
       traversal = balanced_traversal(s1, s2, :balanced_callback)
       expect(traversal.result).to eq(result)
     end
 
-    it 'traverses s2 -> s1 correctly' do
+    it "traverses s2 -> s1 correctly" do
       traversal = balanced_traversal(s2, s1, :balanced_callback)
       expect(traversal.result).to eq(balanced_reverse(result))
     end
   end
 
-  shared_examples 'without a #change callback' do |s1, s2, result|
-    it 'traverses s1 -> s2 correctly' do
+  shared_examples "without a #change callback" do |s1, s2, result|
+    it "traverses s1 -> s2 correctly" do
       traversal = balanced_traversal(s1, s2, :balanced_callback_no_change)
       expect(traversal.result).to eq(map_to_no_change(result))
     end
 
-    it 'traverses s2 -> s1 correctly' do
+    it "traverses s2 -> s1 correctly" do
       traversal = balanced_traversal(s2, s1, :balanced_callback_no_change)
       expect(traversal.result).to eq(map_to_no_change(balanced_reverse(result)))
     end
   end
 
   describe "identical string sequences ('abc')" do
-    s1 = s2 = 'abc'
+    s1 = s2 = "abc"
 
     result = [
-      ['=', 0, 0],
-      ['=', 1, 1],
-      ['=', 2, 2]
+      ["=", 0, 0],
+      ["=", 1, 1],
+      ["=", 2, 2]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'identical array sequences %w(a b c)' do
-    s1 = s2 = %w(a b c)
+  describe "identical array sequences %w(a b c)" do
+    s1 = s2 = %w[a b c]
 
     result = [
-      ['=', 0, 0],
-      ['=', 1, 1],
-      ['=', 2, 2]
+      ["=", 0, 0],
+      ["=", 1, 1],
+      ["=", 2, 2]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(a b c) & %w(a x c)' do
-    s1 = %w(a b c)
-    s2 = %w(a x c)
+  describe "sequences %w(a b c) & %w(a x c)" do
+    s1 = %w[a b c]
+    s2 = %w[a x c]
 
     result = [
-      ['=', 0, 0],
-      ['!', 1, 1],
-      ['=', 2, 2]
+      ["=", 0, 0],
+      ["!", 1, 1],
+      ["=", 2, 2]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(a x y c) & %w(a v w c)' do
-    s1 = %w(a x y c)
-    s2 = %w(a v w c)
+  describe "sequences %w(a x y c) & %w(a v w c)" do
+    s1 = %w[a x y c]
+    s2 = %w[a v w c]
 
     result = [
-      ['=', 0, 0],
-      ['!', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3]
+      ["=", 0, 0],
+      ["!", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(x y c) & %w(v w c)' do
-    s1 = %w(x y c)
-    s2 = %w(v w c)
+  describe "sequences %w(x y c) & %w(v w c)" do
+    s1 = %w[x y c]
+    s2 = %w[v w c]
     result = [
-      ['!', 0, 0],
-      ['!', 1, 1],
-      ['=', 2, 2]
+      ["!", 0, 0],
+      ["!", 1, 1],
+      ["=", 2, 2]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(a x y z) & %w(b v w)' do
-    s1 = %w(a x y z)
-    s2 = %w(b v w)
+  describe "sequences %w(a x y z) & %w(b v w)" do
+    s1 = %w[a x y z]
+    s2 = %w[b v w]
     result = [
-      ['!', 0, 0],
-      ['!', 1, 1],
-      ['!', 2, 2],
-      ['<', 3, 3]
+      ["!", 0, 0],
+      ["!", 1, 1],
+      ["!", 2, 2],
+      ["<", 3, 3]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(a z) & %w(a)' do
-    s1 = %w(a z)
-    s2 = %w(a)
+  describe "sequences %w(a z) & %w(a)" do
+    s1 = %w[a z]
+    s2 = %w[a]
     result = [
-      ['=', 0, 0],
-      ['<', 1, 1]
+      ["=", 0, 0],
+      ["<", 1, 1]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(z a) & %w(a)' do
-    s1 = %w(z a)
-    s2 = %w(a)
+  describe "sequences %w(z a) & %w(a)" do
+    s1 = %w[z a]
+    s2 = %w[a]
     result = [
-      ['<', 0, 0],
-      ['=', 1, 0]
+      ["<", 0, 0],
+      ["=", 1, 0]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(a b c) & %w(x y z)' do
-    s1 = %w(a b c)
-    s2 = %w(x y z)
+  describe "sequences %w(a b c) & %w(x y z)" do
+    s1 = %w[a b c]
+    s2 = %w[x y z]
     result = [
-      ['!', 0, 0],
-      ['!', 1, 1],
-      ['!', 2, 2]
+      ["!", 0, 0],
+      ["!", 1, 1],
+      ["!", 2, 2]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'sequences %w(abcd efgh ijkl mnoopqrstuvwxyz) & []' do
-    s1 = %w(abcd efgh ijkl mnopqrstuvwxyz)
+  describe "sequences %w(abcd efgh ijkl mnoopqrstuvwxyz) & []" do
+    s1 = %w[abcd efgh ijkl mnopqrstuvwxyz]
     s2 = []
     result = [
-      ['<', 0, 0],
-      ['<', 1, 0],
-      ['<', 2, 0],
-      ['<', 3, 0]
+      ["<", 0, 0],
+      ["<", 1, 0],
+      ["<", 2, 0],
+      ["<", 3, 0]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(a b c) & %q(a x c)' do
-    s1 = 'a b c'
-    s2 = 'a x c'
+  describe "strings %q(a b c) & %q(a x c)" do
+    s1 = "a b c"
+    s2 = "a x c"
 
     result = [
-      ['=', 0, 0],
-      ['=', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3],
-      ['=', 4, 4]
+      ["=", 0, 0],
+      ["=", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3],
+      ["=", 4, 4]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(a x y c) & %q(a v w c)' do
-    s1 = 'a x y c'
-    s2 = 'a v w c'
+  describe "strings %q(a x y c) & %q(a v w c)" do
+    s1 = "a x y c"
+    s2 = "a v w c"
 
     result = [
-      ['=', 0, 0],
-      ['=', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3],
-      ['!', 4, 4],
-      ['=', 5, 5],
-      ['=', 6, 6]
+      ["=", 0, 0],
+      ["=", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3],
+      ["!", 4, 4],
+      ["=", 5, 5],
+      ["=", 6, 6]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(x y c) & %q(v w c)' do
-    s1 = 'x y c'
-    s2 = 'v w c'
+  describe "strings %q(x y c) & %q(v w c)" do
+    s1 = "x y c"
+    s2 = "v w c"
     result = [
-      ['!', 0, 0],
-      ['=', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3],
-      ['=', 4, 4]
+      ["!", 0, 0],
+      ["=", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3],
+      ["=", 4, 4]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(a x y z) & %q(b v w)' do
-    s1 = 'a x y z'
-    s2 = 'b v w'
+  describe "strings %q(a x y z) & %q(b v w)" do
+    s1 = "a x y z"
+    s2 = "b v w"
     result = [
-      ['!', 0, 0],
-      ['=', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3],
-      ['!', 4, 4],
-      ['<', 5, 5],
-      ['<', 6, 5]
+      ["!", 0, 0],
+      ["=", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3],
+      ["!", 4, 4],
+      ["<", 5, 5],
+      ["<", 6, 5]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(a z) & %q(a)' do
-    s1 = 'a z'
-    s2 = 'a'
+  describe "strings %q(a z) & %q(a)" do
+    s1 = "a z"
+    s2 = "a"
     result = [
-      ['=', 0, 0],
-      ['<', 1, 1],
-      ['<', 2, 1]
+      ["=", 0, 0],
+      ["<", 1, 1],
+      ["<", 2, 1]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(z a) & %q(a)' do
-    s1 = 'z a'
-    s2 = 'a'
+  describe "strings %q(z a) & %q(a)" do
+    s1 = "z a"
+    s2 = "a"
     result = [
-      ['<', 0, 0],
-      ['<', 1, 0],
-      ['=', 2, 0]
+      ["<", 0, 0],
+      ["<", 1, 0],
+      ["=", 2, 0]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(a b c) & %q(x y z)' do
-    s1 = 'a b c'
-    s2 = 'x y z'
+  describe "strings %q(a b c) & %q(x y z)" do
+    s1 = "a b c"
+    s2 = "x y z"
     result = [
-      ['!', 0, 0],
-      ['=', 1, 1],
-      ['!', 2, 2],
-      ['=', 3, 3],
-      ['!', 4, 4]
+      ["!", 0, 0],
+      ["=", 1, 1],
+      ["!", 2, 2],
+      ["=", 3, 3],
+      ["!", 4, 4]
     ]
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 
-  describe 'strings %q(abcd efgh ijkl mnopqrstuvwxyz) & %q()' do
-    s1 = 'abcd efgh ijkl mnopqrstuvwxyz'
-    s2 = ''
+  describe "strings %q(abcd efgh ijkl mnopqrstuvwxyz) & %q()" do
+    s1 = "abcd efgh ijkl mnopqrstuvwxyz"
+    s2 = ""
+    # standard:disable Layout/ExtraSpacing
     result = [
-      ['<',  0, 0],
-      ['<',  1, 0],
-      ['<',  2, 0],
-      ['<',  3, 0],
-      ['<',  4, 0],
-      ['<',  5, 0],
-      ['<',  6, 0],
-      ['<',  7, 0],
-      ['<',  8, 0],
-      ['<',  9, 0],
-      ['<', 10, 0],
-      ['<', 11, 0],
-      ['<', 12, 0],
-      ['<', 13, 0],
-      ['<', 14, 0],
-      ['<', 15, 0],
-      ['<', 16, 0],
-      ['<', 17, 0],
-      ['<', 18, 0],
-      ['<', 19, 0],
-      ['<', 20, 0],
-      ['<', 21, 0],
-      ['<', 22, 0],
-      ['<', 23, 0],
-      ['<', 24, 0],
-      ['<', 25, 0],
-      ['<', 26, 0],
-      ['<', 27, 0],
-      ['<', 28, 0]
+      ["<",  0, 0],
+      ["<",  1, 0],
+      ["<",  2, 0],
+      ["<",  3, 0],
+      ["<",  4, 0],
+      ["<",  5, 0],
+      ["<",  6, 0],
+      ["<",  7, 0],
+      ["<",  8, 0],
+      ["<",  9, 0],
+      ["<", 10, 0],
+      ["<", 11, 0],
+      ["<", 12, 0],
+      ["<", 13, 0],
+      ["<", 14, 0],
+      ["<", 15, 0],
+      ["<", 16, 0],
+      ["<", 17, 0],
+      ["<", 18, 0],
+      ["<", 19, 0],
+      ["<", 20, 0],
+      ["<", 21, 0],
+      ["<", 22, 0],
+      ["<", 23, 0],
+      ["<", 24, 0],
+      ["<", 25, 0],
+      ["<", 26, 0],
+      ["<", 27, 0],
+      ["<", 28, 0]
     ]
+    # standard:enable Layout/ExtraSpacing
 
-    it_has_behavior 'with a #change callback', s1, s2, result
-    it_has_behavior 'without a #change callback', s1, s2, result
+    it_has_behavior "with a #change callback", s1, s2, result
+    it_has_behavior "without a #change callback", s1, s2, result
   end
 end
diff --git a/spec/traverse_sequences_spec.rb b/spec/traverse_sequences_spec.rb
index b185e1d..8e9928f 100644
--- a/spec/traverse_sequences_spec.rb
+++ b/spec/traverse_sequences_spec.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
+require "spec_helper"
 
-describe 'Diff::LCS.traverse_sequences' do
-  describe 'callback with no finishers' do
-    describe 'over (seq1, seq2)' do
+describe "Diff::LCS.traverse_sequences" do
+  describe "callback with no finishers" do
+    describe "over (seq1, seq2)" do
       before(:each) do
         @callback_s1_s2 = simple_callback_no_finishers
         Diff::LCS.traverse_sequences(seq1, seq2, @callback_s1_s2)
@@ -13,27 +13,27 @@ describe 'Diff::LCS.traverse_sequences' do
         Diff::LCS.traverse_sequences(seq2, seq1, @callback_s2_s1)
       end
 
-      it 'has the correct LCS result on left-matches' do
+      it "has the correct LCS result on left-matches" do
         expect(@callback_s1_s2.matched_a).to eq(correct_lcs)
         expect(@callback_s2_s1.matched_a).to eq(correct_lcs)
       end
 
-      it 'has the correct LCS result on right-matches' do
+      it "has the correct LCS result on right-matches" do
         expect(@callback_s1_s2.matched_b).to eq(correct_lcs)
         expect(@callback_s2_s1.matched_b).to eq(correct_lcs)
       end
 
-      it 'has the correct skipped sequences with the left sequence' do
+      it "has the correct skipped sequences with the left sequence" do
         expect(@callback_s1_s2.discards_a).to eq(skipped_seq1)
         expect(@callback_s2_s1.discards_a).to eq(skipped_seq2)
       end
 
-      it 'has the correct skipped sequences with the right sequence' do
+      it "has the correct skipped sequences with the right sequence" do
         expect(@callback_s1_s2.discards_b).to eq(skipped_seq2)
         expect(@callback_s2_s1.discards_b).to eq(skipped_seq1)
       end
 
-      it 'does not have anything done markers from the left or right sequences' do
+      it "does not have anything done markers from the left or right sequences" do
         expect(@callback_s1_s2.done_a).to be_empty
         expect(@callback_s1_s2.done_b).to be_empty
         expect(@callback_s2_s1.done_a).to be_empty
@@ -41,64 +41,64 @@ describe 'Diff::LCS.traverse_sequences' do
       end
     end
 
-    describe 'over (hello, hello)' do
+    describe "over (hello, hello)" do
       before(:each) do
         @callback = simple_callback_no_finishers
         Diff::LCS.traverse_sequences(hello, hello, @callback)
       end
 
-      it 'has the correct LCS result on left-matches' do
-        expect(@callback.matched_a).to eq(hello.split(//))
+      it "has the correct LCS result on left-matches" do
+        expect(@callback.matched_a).to eq(hello.chars)
       end
 
-      it 'has the correct LCS result on right-matches' do
-        expect(@callback.matched_b).to eq(hello.split(//))
+      it "has the correct LCS result on right-matches" do
+        expect(@callback.matched_b).to eq(hello.chars)
       end
 
-      it 'has the correct skipped sequences with the left sequence', :only => true do
+      it "has the correct skipped sequences with the left sequence" do
         expect(@callback.discards_a).to be_empty
       end
 
-      it 'has the correct skipped sequences with the right sequence' do
+      it "has the correct skipped sequences with the right sequence" do
         expect(@callback.discards_b).to be_empty
       end
 
-      it 'does not have anything done markers from the left or right sequences' do
+      it "does not have anything done markers from the left or right sequences" do
         expect(@callback.done_a).to be_empty
         expect(@callback.done_b).to be_empty
       end
     end
 
-    describe 'over (hello_ary, hello_ary)' do
+    describe "over (hello_ary, hello_ary)" do
       before(:each) do
         @callback = simple_callback_no_finishers
         Diff::LCS.traverse_sequences(hello_ary, hello_ary, @callback)
       end
 
-      it 'has the correct LCS result on left-matches' do
+      it "has the correct LCS result on left-matches" do
         expect(@callback.matched_a).to eq(hello_ary)
       end
 
-      it 'has the correct LCS result on right-matches' do
+      it "has the correct LCS result on right-matches" do
         expect(@callback.matched_b).to eq(hello_ary)
       end
 
-      it 'has the correct skipped sequences with the left sequence' do
+      it "has the correct skipped sequences with the left sequence" do
         expect(@callback.discards_a).to be_empty
       end
 
-      it 'has the correct skipped sequences with the right sequence' do
+      it "has the correct skipped sequences with the right sequence" do
         expect(@callback.discards_b).to be_empty
       end
 
-      it 'does not have anything done markers from the left or right sequences' do
+      it "does not have anything done markers from the left or right sequences" do
         expect(@callback.done_a).to be_empty
         expect(@callback.done_b).to be_empty
       end
     end
   end
 
-  describe 'callback with finisher' do
+  describe "callback with finisher" do
     before(:each) do
       @callback_s1_s2 = simple_callback
       Diff::LCS.traverse_sequences(seq1, seq2, @callback_s1_s2)
@@ -106,32 +106,32 @@ describe 'Diff::LCS.traverse_sequences' do
       Diff::LCS.traverse_sequences(seq2, seq1, @callback_s2_s1)
     end
 
-    it 'has the correct LCS result on left-matches' do
+    it "has the correct LCS result on left-matches" do
       expect(@callback_s1_s2.matched_a).to eq(correct_lcs)
       expect(@callback_s2_s1.matched_a).to eq(correct_lcs)
     end
 
-    it 'has the correct LCS result on right-matches' do
+    it "has the correct LCS result on right-matches" do
       expect(@callback_s1_s2.matched_b).to eq(correct_lcs)
       expect(@callback_s2_s1.matched_b).to eq(correct_lcs)
     end
 
-    it 'has the correct skipped sequences for the left sequence' do
+    it "has the correct skipped sequences for the left sequence" do
       expect(@callback_s1_s2.discards_a).to eq(skipped_seq1)
       expect(@callback_s2_s1.discards_a).to eq(skipped_seq2)
     end
 
-    it 'has the correct skipped sequences for the right sequence' do
+    it "has the correct skipped sequences for the right sequence" do
       expect(@callback_s1_s2.discards_b).to eq(skipped_seq2)
       expect(@callback_s2_s1.discards_b).to eq(skipped_seq1)
     end
 
-    it 'has done markers differently-sized sequences' do
-      expect(@callback_s1_s2.done_a).to eq([['p', 9, 't', 11]])
+    it "has done markers differently-sized sequences" do
+      expect(@callback_s1_s2.done_a).to eq([["p", 9, "t", 11]])
       expect(@callback_s1_s2.done_b).to be_empty
 
       expect(@callback_s2_s1.done_a).to be_empty
-      expect(@callback_s2_s1.done_b).to eq([['t', 11, 'p', 9]])
+      expect(@callback_s2_s1.done_b).to eq([["t", 11, "p", 9]])
     end
   end
 end