Applied Rubocop rules that I like

- Other linting configuration also applied.
- Soft-deprecating versions older than 2.3.

.autotest

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rubygems'
 
-# vim: syntax=ruby
+# vim: ft=ruby

.fasterer.yml

@@ -0,0 +1,4 @@
+exclude_paths:
+  - lib/diff/lcs.rb # sort_vs_sort_by on priority_compare
+  - Rakefile # each_with_index vs while
+  - spec/spec_helper.rb

.hoerc

@@ -1,30 +1,11 @@
 ---
 exclude: !ruby/regexp '/
   \.(?:
-      tmp |
-      swp
-    )$
+    tmp |
+    swp
+  )$
   |
   \.(?:
-      autotest |
-      byebug_history |
-      gemtest |
-      gitignore |
-      hoerc |
-      minitest.rb |
-      simplecov-prelude.rb)$
-  |
-  \.(?:
-      coveralls |
-      pullreview |
-      travis |
-      appveyor
-     )\.yml$
-  |
-  (?i:TAGS)$
-  |
-  \.(?:
-      DS_Store|
       bundle|
       git|
       hg|
@@ -35,11 +16,36 @@ exclude: !ruby/regexp '/
   |
   [gG]emfile(?:\.lock)?
   |
-  support\/
+  (?:
+    support |
+    research
+  )\/
   |
-  research\/
+  \.(?:
+    appveyor |
+    coveralls |
+    fasterer |
+    pullreview |
+    rubocop.* |
+    travis |
+    unused
+    )\.yml$
+  |
+  (?i:TAGS)$
+  |
+  \.(?:
+      DS_Store |
+      autotest |
+      byebug_history |
+      gemtest |
+      gitattributes |
+      gitignore |
+      hoerc |
+      minitest.rb |
+      simplecov-prelude.rb
+  )$
   |
   \.gemspec$
   |
-  Vagrantfile
+  ^Vagrantfile$
   /x'

.rubocop.yml

@@ -0,0 +1,120 @@
+---
+AllCops:
+  DisplayCopNames: true
+  DisplayStyleGuide: true
+  ExtraDetails: true
+  Exclude:
+    - diff-lcs.gemspec
+    - research/**/*
+
+Layout/AlignParameters:
+  EnforcedStyle: with_fixed_indentation
+
+Layout/DotPosition:
+  EnforcedStyle: trailing
+
+Layout/ExtraSpacing:
+  Exclude:
+   - spec/**/*
+
+Layout/MultilineMethodCallIndentation:
+  EnforcedStyle: indented
+
+Metrics/LineLength:
+  Max: 110
+
+Naming/FileName:
+  Exclude:
+    - lib/diff-lcs.rb
+
+Naming/MemoizedInstanceVariableName:
+  Exclude: []
+
+Naming/UncommunicativeMethodParamName:
+  Exclude:
+    - lib/diff/lcs/internals.rb
+    - spec/spec_helper.rb
+
+Naming/VariableNumber:
+  Exclude: []
+
+Performance/Caller:
+  Exclude: []
+
+Security/MarshalLoad:
+  Exclude: []
+
+Security/YAMLLoad:
+  Exclude: []
+
+Style/BlockDelimiters:
+  EnforcedStyle: semantic
+  ProceduralMethods:
+    - trace
+    - assert_raises
+    - spec
+  FunctionalMethods:
+    - let
+    - subject
+    - add_discovery
+    - require_do
+    - it
+  IgnoredMethods:
+    - expect
+
+Style/Documentation:
+  Exclude:
+    - lib/diff/lcs/array.rb
+    - lib/diff/lcs/string.rb
+    - spec/spec_helper.rb
+
+# Until there is a hard drop of Ruby 1.8
+Style/HashSyntax:
+  Enabled: false
+
+Style/PercentLiteralDelimiters:
+  PreferredDelimiters:
+    default: ()
+    '%i': '()'
+    '%I': '()'
+    '%r': '{}'
+    '%w': '()'
+    '%W': '()'
+
+Style/RescueModifier:
+  Enabled: false
+
+Style/RescueStandardError:
+  EnforcedStyle: implicit
+
+Style/SignalException:
+  EnforcedStyle: semantic
+
+Layout/IndentHeredoc: { Enabled: false }
+Metrics/AbcSize: { Enabled: false }
+Metrics/BlockLength: { Enabled: false }
+Metrics/BlockNesting: { Enabled: false }
+Metrics/ClassLength: { Enabled: false }
+Metrics/CyclomaticComplexity: { Enabled: false }
+Metrics/MethodLength: { Enabled: false}
+Metrics/ModuleLength: { Enabled: false}
+Metrics/PerceivedComplexity: { Enabled: false }
+Style/AccessModifierDeclarations: { Enabled: false }
+Style/AndOr: { Enabled: false }
+Style/AsciiComments: { Enabled: false }
+Style/BarePercentLiterals: { Enabled: false }
+Style/ClassAndModuleChildren: { Enabled: false }
+Style/ClassCheck: { Enabled: false }
+Style/CommentedKeyword: { Enabled: false }
+Style/DoubleNegation: { Enabled: false }
+Style/EmptyMethod: { Enabled: false }
+Style/ExpandPathArguments: { Enabled: false }
+Style/FormatString: { Enabled: false }
+Style/FormatStringToken: { Enabled: false }
+Style/MultilineBlockChain: { Enabled: false }
+Style/ParallelAssignment: { Enabled: false }
+Style/SafeNavigation: { Enabled: false }
+Style/SpecialGlobalVars: { Enabled: false }
+Style/SymbolArray: { Enabled: false }
+Style/SymbolProc: { Enabled: false }
+Style/WordArray: { Enabled: false }

.travis.yml

@@ -1,33 +1,25 @@
 ---
 language: ruby
 rvm:
-  - 2.5.0
-  - 2.4.3
-  - 2.3.6
-  - 2.2.9
-  - 2.1.10
-  - 2.0.0
-  - 1.9.3
-  - 1.8.7
-  - ree
+  - 2.6.0
+  - 2.5.3
+  - 2.4.5
+  - 2.3.8
+  - jruby-9.2.5.0
+  - jruby-9.1.17.0
+  - jruby-9.0.5.0
+  - jruby-head
   - ruby-head
-  - jruby-19mode
 matrix:
   allow_failures:
+    - rvm: jruby-head
     - rvm: ruby-head
-    - rvm: 1.8.7
-    - rvm: ree
+  fast_finish: true
 gemfile:
   - Gemfile
 before_script:
   - bundle exec rake travis:before -t
 script: bundle exec rake travis
 after_script:
   - bundle exec rake travis:after -t
-notifications:
-  email:
-    recipients:
-      - [email protected]
-    on_success: change
-    on_failure: always
 sudo: false

Gemfile

@@ -1,20 +1,20 @@
-# -*- ruby -*-
+# frozen_string_literal: true
 
 # 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 'rdoc', '< 4'
   gem 'rake', '< 11'
+  gem 'rdoc', '< 4'
 elsif RUBY_VERSION >= '2.0'
   if RUBY_ENGINE == 'ruby'
-    gem 'simplecov', '~> 0.7'
     gem 'coveralls', '~> 0.7'
+    gem 'simplecov', '~> 0.7'
   end
 end
 
 gemspec
 
-# vim: syntax=ruby
+# vim: ft=ruby

History.md

@@ -1,3 +1,8 @@
+## 1.NEXT / 2019-MM-DD
+
+*   Ruby versions lower than 2.3 are soft-deprecated and will not be run as part
+    of the CI process any longer.
+
 ## 1.3 / 2017-01-18
 
 *   Bugs fixed:

Rakefile

@@ -1,4 +1,4 @@
-# -*- ruby encoding: utf-8 -*-
+# frozen_string_literal: true
 
 require 'rubygems'
 require 'rspec'
@@ -11,14 +11,14 @@ Hoe.plugin :gemspec2
 Hoe.plugin :git
 Hoe.plugin :travis
 
-spec = Hoe.spec 'diff-lcs' do
+_spec = Hoe.spec 'diff-lcs' do
   developer('Austin Ziegler', '[email protected]')
 
   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.licenses = ['MIT', 'Artistic-2.0', 'GPL-2.0+']
 
   extra_dev_deps << ['hoe-doofus', '~> 1.0']
   extra_dev_deps << ['hoe-gemspec2', '~> 1.1']

autotest/discover.rb

@@ -1 +1,3 @@
-Autotest.add_discovery { "rspec2" }
+# frozen_string_literal: true
+
+Autotest.add_discovery { 'rspec2' }

bin/htmldiff

@@ -1,4 +1,5 @@
-#!ruby -w
+#! /usr/bin/env ruby -w
+# frozen_string_literal: true
 
 require 'diff/lcs'
 require 'diff/lcs/htmldiff'
@@ -10,8 +11,8 @@ rescue LoadError
 end
 
 if ARGV.size < 2 or ARGV.size > 3
-  $stderr.puts "usage: #{File.basename($0)} old new [output.html]"
-  $stderr.puts "       #{File.basename($0)} old new > output.html"
+  warn "usage: #{File.basename($0)} old new [output.html]"
+  warn "       #{File.basename($0)} old new > output.html"
   exit 127
 end
 
@@ -23,10 +24,12 @@ 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
 else
   htmldiff.run
 end
+
+# vim: ft=ruby

bin/ldiff

@@ -1,6 +1,9 @@
-#!ruby -w
+#! /usr/bin/env ruby -w
+# frozen_string_literal: true
 
 require 'diff/lcs'
 require 'diff/lcs/ldiff'
 
 exit Diff::LCS::Ldiff.run(ARGV)
+
+# vim: ft=ruby