dep: move dev dependencies into Gemfile

Pin the dev dependencies so that dependabot will tell us when new
versions are out and we'll get CI results automatically.

Make rubocop dependencies conditional on Ruby 3 to work around the
constraint of rubocop-shopify requiring ruby 2.7 or higher.

Bump rubocop versions and regenerate the rubocop TODO file.

.rubocop.yml

@@ -12,6 +12,7 @@ AllCops:
     - 'lib/nokogiri/css/parser.rb' # generated by racc
     - 'lib/nokogiri/css/tokenizer.rb' # generated by rex
     - 'lib/nokogiri/jruby/nokogiri_jars.rb' # generated by jar-dependencies
+  TargetRubyVersion: "2.6"
 Naming/MethodName:
   Enabled: false
 Naming/FileName:

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2022-04-27 12:13:42 UTC using RuboCop version 1.28.2.
+# on 2022-08-23 16:20:00 UTC using RuboCop version 1.35.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -13,10 +13,10 @@ Lint/MissingSuper:
     - 'lib/nokogiri/html5/document_fragment.rb'
     - 'lib/nokogiri/xml/document_fragment.rb'
 
-# Offense count: 17
+# Offense count: 4
 # Configuration parameters: CountBlocks.
 Metrics/BlockNesting:
-  Max: 5
+  Max: 4
 
 # Offense count: 2
 # Configuration parameters: Max, CountKeywordArgs.
@@ -31,26 +31,21 @@ Performance/CollectionLiteralInLoop:
     - 'test/xml/test_dtd_encoding.rb'
     - 'test/xml/test_node_reparenting.rb'
 
-# Offense count: 17
-# This cop supports safe auto-correction (--auto-correct).
-# Configuration parameters: AllowedVars.
-Style/FetchEnvVar:
-  Exclude:
-    - 'ext/nokogiri/extconf.rb'
-    - 'rakelib/debug.rake'
-    - 'rakelib/extensions.rake'
-    - 'rakelib/rdoc.rake'
-    - 'test/helper.rb'
+# Offense count: 23
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: def_self, self_class
+Style/ClassMethodsDefinitions:
+  Enabled: false
 
 # Offense count: 2
 Style/MissingRespondToMissing:
   Exclude:
     - 'lib/nokogiri/xml/builder.rb'
 
 # Offense count: 73
-# This cop supports safe auto-correction (--auto-correct).
+# This cop supports safe autocorrection (--autocorrect).
 # Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, AllowedPatterns, IgnoredPatterns.
 # URISchemes: http, https
-# AllowedPatterns: \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z), \A\s*(remote_)?test(_\w+)?\s.*(do|->)(\s|\Z)
 Layout/LineLength:
   Max: 250

Gemfile

@@ -3,3 +3,35 @@
 source "https://rubygems.org"
 
 gemspec
+
+group :development do
+  # bootstrapping
+  gem "bundler", "~> 2.3"
+  gem "rake", "= 13.0.6"
+
+  # building extensions
+  gem "rake-compiler", "= 1.2.0"
+  gem "rake-compiler-dock", "= 1.2.2"
+
+  # documentation
+  gem "hoe-markdown", "= 1.4.0"
+  gem "rdoc", "= 6.4.0"
+
+  # parser generator
+  gem "rexical", "= 1.0.7"
+
+  # tests
+  gem "minitest", "= 5.16.3"
+  gem "minitest-reporters", "= 1.5.0"
+  gem "ruby_memcheck", "= 1.0.3"
+  gem "simplecov", "= 0.21.2"
+
+  # rubocop
+  if Gem::Requirement.new("~> 3.0").satisfied_by?(Gem::Version.new(RUBY_VERSION))
+    gem "rubocop", "= 1.35.1"
+    gem "rubocop-minitest", "= 0.21.0"
+    gem "rubocop-performance", "= 1.14.3"
+    gem "rubocop-rake", "= 0.6.0"
+    gem "rubocop-shopify", "= 2.9.0"
+  end
+end

nokogiri.gemspec

@@ -339,22 +339,5 @@ Gem::Specification.new do |spec|
   end
   spec.add_runtime_dependency("racc", "~> 1.4")
 
-  spec.add_development_dependency("bundler", "~> 2.3")
-  spec.add_development_dependency("hoe-markdown", "~> 1.4.0")
-  spec.add_development_dependency("minitest", "~> 5.16.2")
-  spec.add_development_dependency("minitest-reporters", "~> 1.5.0")
-  spec.add_development_dependency("rake", "~> 13.0.6")
-  spec.add_development_dependency("rake-compiler", "= 1.2.0")
-  spec.add_development_dependency("rake-compiler-dock", "= 1.2.2")
-  spec.add_development_dependency("rdoc", "~> 6.4.0")
-  spec.add_development_dependency("rexical", "~> 1.0.7")
-  spec.add_development_dependency("rubocop", "~> 1.30.1")
-  spec.add_development_dependency("rubocop-minitest", "~> 0.21.0")
-  spec.add_development_dependency("rubocop-performance", "~> 1.14.2")
-  spec.add_development_dependency("rubocop-rake", "~> 0.6.0")
-  spec.add_development_dependency("rubocop-shopify", "= 2.5.0") # TODO: loosen this after dropping support for Ruby 2.6
-  spec.add_development_dependency("ruby_memcheck", "~> 1.0.3")
-  spec.add_development_dependency("simplecov", "~> 0.21.2")
-
   spec.extensions << "ext/nokogiri/extconf.rb"
 end

rakelib/rubocop.rake

@@ -1,38 +1,43 @@
 # frozen_string_literal: true
 
-require "rubocop/rake_task"
+begin
+  require("rubocop/rake_task")
 
-module RubocopHelper
-  class << self
-    def common_options(task)
-      task.patterns += [
-        "Gemfile", "Rakefile", "nokogiri.gemspec",
-        "bin", "ext", "lib", "oci-images", "rakelib", "scripts", "test",
-      ]
-    end
+  module RubocopHelper
+    class << self
+      def common_options(task)
+        task.patterns += [
+          "Gemfile", "Rakefile", "nokogiri.gemspec",
+          "bin", "ext", "lib", "oci-images", "rakelib", "scripts", "test",
+        ]
+      end
 
-    def generated_files(task)
-      task.patterns += ["lib/nokogiri/css/parser.rb", "lib/nokogiri/css/tokenizer.rb"]
-      task.options << "--only=Style/FrozenStringLiteralComment"
+      def generated_files(task)
+        task.patterns += ["lib/nokogiri/css/parser.rb", "lib/nokogiri/css/tokenizer.rb"]
+        task.options << "--only=Style/FrozenStringLiteralComment"
+      end
     end
   end
-end
 
-namespace "rubocop" do
-  desc "Generate the rubocop todo list"
-  RuboCop::RakeTask.new("todo") do |task|
-    RubocopHelper.common_options(task)
-    task.options << "--auto-gen-config"
-  end
-  Rake::Task["rubocop:todo:auto_correct"].clear
+  namespace("rubocop") do
+    desc("Generate the rubocop todo list")
+    RuboCop::RakeTask.new("todo") do |task|
+      RubocopHelper.common_options(task)
+      task.options << "--auto-gen-config"
+    end
+    Rake::Task["rubocop:todo:autocorrect"].clear
+    Rake::Task["rubocop:todo:autocorrect_all"].clear
 
-  desc "Run all checks on a subset of directories"
-  RuboCop::RakeTask.new("check") { |task| RubocopHelper.common_options(task) }
-  RuboCop::RakeTask.new("check") { |task| RubocopHelper.generated_files(task) }
+    desc("Run all checks on a subset of directories")
+    RuboCop::RakeTask.new("check") { |task| RubocopHelper.common_options(task) }
+    RuboCop::RakeTask.new("check") { |task| RubocopHelper.generated_files(task) }
 
-  desc "Shortcut for rubocop:check:auto_correct"
-  task fix: "rubocop:check:auto_correct"
-end
+    desc("Shortcut for rubocop:check:autocorrect")
+    task(fix: "rubocop:check:autocorrect")
+  end
 
-desc "Shortcut for rubocop:check"
-task rubocop: "rubocop:check"
+  desc("Shortcut for rubocop:check")
+  task(rubocop: "rubocop:check")
+rescue LoadError => e
+  warn("WARNING: rubocop is not available in this environment: #{e}")
+end