Modernize ice_nine for the current Ruby ecosystem

.github/workflows/ci.yml

@@ -1,18 +1,21 @@
 name: CI
 
-on: push
+on:
+  push:
+    branches: [master, main]
+  pull_request:
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
 
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2']
+        ruby-version: ['3.3', '3.4', '4.0']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
@@ -22,6 +25,35 @@ jobs:
 
     - name: Run tests
       run: bundle exec rspec
+      env:
+        COVERAGE: 'true'
 
-    - name: Run mutant
-      run: bundle exec mutant run
+  rubocop:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '4.0'
+        bundler-cache: true
+
+    - name: Run RuboCop
+      run: bundle exec rubocop
+
+  audit:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '4.0'
+        bundler-cache: true
+
+    - name: Run bundler-audit
+      run: bundle exec bundler-audit check --update

.rubocop.yml

@@ -1,8 +1,93 @@
+plugins:
+  - rubocop-performance
+  - rubocop-rspec
+
 AllCops:
+  NewCops: enable
+  TargetRubyVersion: 3.3
+  SuggestExtensions: false
   Exclude:
-    - 'Gemfile'
-    - 'Gemfile.devtools'
     - 'benchmarks/**/*'
-    - 'ice_nine.gemspec'
     - 'vendor/**/*'
-    - 'Guardfile'
+
+# This codebase favours a very dense, "one class/module per concept" style
+# with lots of tiny classes (e.g. lib/ice_nine/freezer/*.rb), so the
+# class-level documentation cop is enough; per-file/module-length limits
+# below are relaxed to match that style rather than forcing artificial
+# splits.
+Style/Documentation:
+  Enabled: true
+
+Style/ClassAndModuleChildren:
+  Exclude:
+    - 'spec/**/*_spec.rb'
+
+Metrics/ClassLength:
+  Max: 100
+
+Metrics/ModuleLength:
+  Max: 100
+  Exclude:
+    - 'spec/**/*'
+
+Metrics/BlockLength:
+  Exclude:
+    - 'spec/**/*'
+    - 'ice_nine.gemspec'
+
+# The library re-opens IceNine::Freezer for each supported Ruby core class,
+# so short single-purpose subclasses are idiomatic here, not a smell.
+Style/EmptyMethod:
+  EnforcedStyle: expanded
+
+Layout/LineLength:
+  Max: 100
+
+RSpec/MultipleMemoizedHelpers:
+  Enabled: false
+
+RSpec/NestedGroups:
+  Max: 5
+
+RSpec/ExampleLength:
+  Enabled: false
+
+RSpec/MultipleExpectations:
+  Enabled: false
+
+# The suite consistently defines a single `subject` per example group and
+# references it explicitly for readability in multi-line expectations
+# instead of relying on the implicit `is_expected` syntax.
+RSpec/NamedSubject:
+  Enabled: false
+
+# These doubles stand in for arbitrary opaque objects that are only ever
+# identity-compared (`be(...)`); there is no real interface to verify them
+# against.
+RSpec/VerifiedDoubles:
+  Enabled: false
+
+# element_reader_spec.rb intentionally defines and removes real global
+# constants (Hash::Test, Application::User, Mash::State, ...) to exercise
+# IceNine::Freezer's name-based constant lookup across namespaces -- that is
+# the exact behaviour under test, not a leaky-state accident stub_const
+# would paper over.
+RSpec/RemoveConst:
+  Exclude:
+    - 'spec/unit/ice_nine/freezer/class_methods/element_reader_spec.rb'
+
+RSpec/LeakyConstantDeclaration:
+  Exclude:
+    - 'spec/unit/ice_nine/freezer/class_methods/element_reader_spec.rb'
+
+RSpec/BeforeAfterAll:
+  Exclude:
+    - 'spec/unit/ice_nine/freezer/class_methods/element_reader_spec.rb'
+
+Lint/ConstantDefinitionInBlock:
+  Exclude:
+    - 'spec/unit/ice_nine/freezer/class_methods/element_reader_spec.rb'
+
+Lint/EmptyClass:
+  Exclude:
+    - 'spec/unit/ice_nine/freezer/class_methods/element_reader_spec.rb'

.ruby-version

@@ -0,0 +1 @@
+4.0.6

CONTRIBUTING.md

@@ -7,5 +7,5 @@ Contributing
   * Follow this [style guide](https://github.com/dkubb/styleguide).
 * Add specs for it. This is important so I don't break it in a future version unintentionally. Tests must cover all branches within the code, and code must be fully covered.
 * Commit, do not mess with Rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
-* Run "rake ci". This must pass and not show any regressions in the metrics for the code to be merged.
+* Run `bundle exec rake`. This runs the spec suite (with 100% line/branch coverage enforced) and RuboCop, and must pass with no regressions for the code to be merged.
 * Send me a pull request. Bonus points for topic branches.

Gemfile

@@ -1,15 +1,23 @@
-# encoding: utf-8
+# frozen_string_literal: true
 
 source 'https://rubygems.org'
 
 gemspec
 
 group :development, :test do
-  gem 'rspec',        '~> 3.8', '>= 3.8.0'
-  gem 'mutant',       github: 'mbj/mutant'
-  gem 'mutant-rspec', github: 'mbj/mutant'
+  gem 'rake',  '~> 13.2'
+  gem 'rspec', '~> 3.13'
 
-  source 'https://oss:sxCL1o1navkPi2XnGB5WYBrhpY9iKIPL@gem.mutant.dev' do
-    gem 'mutant-license'
-  end
+  # No longer bundled with Ruby by default since 3.4; the numeric freezer
+  # specs exercise BigDecimal explicitly.
+  gem 'bigdecimal', '~> 3.1'
+
+  gem 'rubocop', '~> 1.75', require: false
+  gem 'rubocop-performance', '~> 1.24', require: false
+  gem 'rubocop-rspec', '~> 3.6', require: false
+
+  gem 'simplecov', '~> 0.22', require: false
+  gem 'yard',      '~> 0.9',  require: false
+
+  gem 'bundler-audit', '~> 0.9', require: false
 end

README.md

@@ -5,15 +5,9 @@ Deep freeze ruby objects
 
 [![Gem Version](https://badge.fury.io/rb/ice_nine.svg)][gem]
 [![Build Status](https://github.com/dkubb/ice_nine/actions/workflows/ci.yml/badge.svg)][ci]
-[![Code Climate](https://codeclimate.com/github/dkubb/ice_nine.png)][codeclimate]
-[![Inline docs](http://inch-ci.org/github/dkubb/ice_nine.svg?branch=master)][inch]
 
 [gem]: https://rubygems.org/gems/ice_nine
 [ci]: https://github.com/dkubb/ice_nine/actions/
-[travis]: https://travis-ci.org/dkubb/ice_nine
-[gemnasium]: https://gemnasium.com/dkubb/ice_nine
-[codeclimate]: https://codeclimate.com/github/dkubb/ice_nine
-[inch]: http://inch-ci.org/github/dkubb/ice_nine
 
 Examples
 --------
@@ -40,6 +34,25 @@ object = Object.new
 object.deep_freeze
 ```
 
+Requirements
+------------
+
+ice_nine requires Ruby 3.3 or newer, and is tested against Ruby 3.3, 3.4
+and 4.0.
+
+Development
+-----------
+
+```shell
+bundle install
+bundle exec rake      # runs the spec suite and RuboCop
+bundle exec rspec     # spec suite only
+bundle exec rubocop   # lint only
+```
+
+Set `COVERAGE=true` when running the spec suite to generate a SimpleCov
+report under `coverage/`; the suite enforces 100% line and branch coverage.
+
 Contributing
 ------------
 

Rakefile

@@ -1,3 +1,15 @@
-# encoding: utf-8
+# frozen_string_literal: true
 
-Rake.application.load_imports
+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
+
+RSpec::Core::RakeTask.new(:spec)
+
+begin
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new(:rubocop)
+rescue LoadError
+  nil
+end
+
+task default: %i[spec rubocop]