Modernize CI matrix and unblock dependency rot

The CI matrix hadn't run since April 2023 and the gem ecosystem has
since dropped support for the older Rubies it covered, leaving every
job red on PRs:

  * Ruby 2.3 / 2.4 - bundler resolved loofah 2.21.x against Rails 5.2,
    which requires Nokogiri::HTML4 (only in nokogiri >= 1.14, itself
    requiring Ruby 2.6+).
  * Ruby 2.5 / 2.6 - activesupport 6.1 + concurrent-ruby >= 1.3.5
    raises uninitialized constant ActiveSupport::LoggerThreadSafeLevel::Logger
    because concurrent-ruby stopped pulling in stdlib Logger.
  * Ruby 2.7 / 3.0 - all 69 specs pass, but simplecov-cobertura 2.1.0
    crashes with REXML::ParseException on rexml >= 3.4.2 at exit and
    fails the job after the suite is green.
  * jruby-head / truffleruby-head - both ship bundler 4.x; the
    \`gem 'bundler', '>= 1.17', '< 3'\` pin in the Gemfile aborts the
    install before any spec runs.

Trim the matrix to Rubies we can actually support today (3.0, 3.1,
3.2, 3.3, 3.4, plus jruby-head and truffleruby-head), bump
required_ruby_version to >= 3.0, and update TargetRubyVersion in
.rubocop.yml to match. Move the codecov upload to the newest stable
Ruby (3.4) and bump the rubocop / yard / check_version jobs along
with it.

Drop the \`gem 'bundler', '>= 1.17', '< 3'\` line - bundler is
environmental, not a runtime dependency, and pinning it broke
Rubies that ship with bundler 4. Bump simplecov-cobertura to ~> 3.1
(which fixes the rexml 3.4.2 crash, see jessebs/simplecov-cobertura#44)
and pin rexml < 3.4.2 to dodge the still-open regression on 3.4.3+
(jessebs/simplecov-cobertura#48).

Replace the deprecated :mingw, :x64_mingw platform tokens with
:windows, drop the now-redundant Ruby 2.6 conditional around the
rubocop/simplecov gems, and drop the Ruby 2.4 mysql2 guard in
spec_helper. Bump actions/checkout to v4 and codecov-action to v4.

Author: justinhoward

.github/workflows/ci.yml

@@ -14,12 +14,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['2.3', '2.4', '2.5', '2.6', '2.7', '3.0', jruby-head, truffleruby-head]
+        ruby: ['3.0', '3.1', '3.2', '3.3', '3.4', jruby-head, truffleruby-head]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
-        env:
-          REDIS_VERSION: ${{ matrix.redis }}
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
@@ -29,40 +27,40 @@ jobs:
         env:
           MYSQL_USER: root
           MYSQL_PASSWORD: root
-      - uses: codecov/codecov-action@v3
-        if: matrix.ruby == '3.0'
+      - uses: codecov/codecov-action@v4
+        if: matrix.ruby == '3.4'
         with:
           files: coverage/coverage.xml
       - run: bin/check-version
 
   rubocop:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '2.7'
+          ruby-version: '3.4'
           bundler-cache: true
       - run: bundle exec rubocop
 
   yard:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.0'
+          ruby-version: '3.4'
           bundler-cache: true
       - run: bin/yardoc --fail-on-warning
 
   check_version:
     runs-on: ubuntu-latest
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.0'
+          ruby-version: '3.4'
           bundler-cache: true
       - run: bin/check-version
 
@@ -71,7 +69,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Publish to RubyGems
         run: |
           mkdir -p $HOME/.gem

.rubocop.yml

@@ -3,7 +3,7 @@ require:
   - rubocop-rspec
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 3.0
 
 Gemspec/DeprecatedAttributeAssignment: { Enabled: true }
 Gemspec/RequireMFA: { Enabled: true }

Gemfile

@@ -8,10 +8,9 @@ gemspec
 # here. This also allows us to use conditional dependencies that depend on the
 # platform
 
-not_jruby = %i[ruby mingw x64_mingw].freeze
+not_jruby = %i[ruby windows].freeze
 
 gem 'actionpack'
-gem 'bundler', '>= 1.17', '< 3'
 gem 'byebug', platforms: not_jruby
 gem 'irb', '~> 1.0'
 # Minimum of 0.5.0 for specific error classes
@@ -25,9 +24,11 @@ gem 'yard', '~> 0.9.25', platforms: not_jruby
 
 gem 'concurrent-ruby'
 
-if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.6')
-  gem 'rubocop', '1.34.1'
-  gem 'rubocop-rspec', '2.12'
-  gem 'simplecov', '~> 0.21.0'
-  gem 'simplecov-cobertura', '~> 2.1'
-end
+gem 'rubocop', '1.34.1'
+gem 'rubocop-rspec', '2.12'
+gem 'simplecov', '~> 0.21.0'
+gem 'simplecov-cobertura', '~> 3.1'
+
+# simplecov-cobertura crashes with REXML::ParseException: Malformed XML on
+# rexml >= 3.4.2. https://github.com/jessebs/simplecov-cobertura/issues/48
+gem 'rexml', '< 3.4.2'

cutoff.gemspec

@@ -24,7 +24,7 @@ Gem::Specification.new do |spec|
   spec.files = Dir['lib/**/*.rb', '*.md', '*.txt', '.yardopts']
   spec.require_paths = ['lib']
 
-  spec.required_ruby_version = '>= 2.3'
+  spec.required_ruby_version = '>= 3.0'
 
   spec.add_development_dependency 'rspec', '~> 3.10'
   spec.add_development_dependency 'rspec-rails', '~> 5.0'

spec/spec_helper.rb

@@ -27,11 +27,7 @@
 require 'sidekiq/testing'
 
 begin
-  # We don't test Mysql2 on Ruby 2.3 since that would require
-  # installing an old EOL version of OpenSSL
-  if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.4')
-    require 'cutoff/patch/mysql2'
-  end
+  require 'cutoff/patch/mysql2'
 rescue LoadError
   # Ok if mysql2 isn't available
 end