Fix CI on Ruby 3.0 and add Ruby 4.0 to the matrix (#411)

## Summary

CI on the oldest supported Ruby breaks as soon as anything calls
`Hash#to_json`, because the newest activesupport that installs there is
incompatible with the latest json release. This keeps the Ruby 3.0 job
green without restricting the json versions the gem allows for users,
and adds Ruby 4.0 to the test matrix so the gem is exercised on the
current Ruby.

## Details

- activesupport 7.1 (the newest installable on Ruby 3.0) calls
`JSON.generate(..., quirks_mode: true)`, which json 3.0 removed, so `{a:
1}.to_json` raises `ArgumentError: unknown keyword: quirks_mode`.
activesupport 7.2.4 and 8.1.x work with json 3.1, so the Gemfile pin is
limited to Ruby 3.0; the gemspec is unchanged.
- Ruby 4.0 no longer ships `ostruct` as a default gem, and the specs
require it, so it is added to the development group. The library already
guards `OpenStruct` with `defined?`.
- The latest RuboCop flags disable/enable pairs around a single
statement (`Style/DirectiveScope`) and fails the rubocop job before
rspec runs, so those directives become `rubocop:disable-next`.
- `git` is pinned below 6 because danger 9.6 references `Git::Base`,
which git 6 no longer loads eagerly.
- The unreleased CHANGELOG heading is now `1.1.1 (Next)`:
danger-changelog only recognizes headings containing `(Next)` or
`[Unreleased]`.
- Includes the Dependabot bumps of the danger-pr-comment workflows to
v0.1.1 (#409, #410).

Author: numbata

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ permissions:
 
 jobs:
   rubocop:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04 # no ubuntu-26.04 builds of Ruby 3.0/3.1 yet; revisit when ubuntu-latest moves
     steps:
       - uses: actions/checkout@v7
       - uses: ruby/setup-ruby@v1
@@ -24,11 +24,11 @@ jobs:
         run: bundle exec rubocop --parallel --format progress
 
   rspec:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04 # no ubuntu-26.04 builds of Ruby 3.0/3.1 yet; revisit when ubuntu-latest moves
     needs: ['rubocop']
     strategy:
       matrix:
-        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4']
+        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4', '4.0']
     steps:
     - name: Check out branch
       uses: actions/checkout@v7

.github/workflows/danger-comment.yml

@@ -7,5 +7,5 @@ on:
 
 jobs:
   comment:
-    uses: numbata/danger-pr-comment/.github/workflows/danger-comment.yml@v0.1.0
+    uses: numbata/danger-pr-comment/.github/workflows/danger-comment.yml@v0.1.1
     secrets: inherit

.github/workflows/danger.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   danger:
-    uses: numbata/danger-pr-comment/.github/workflows/danger-run.yml@v0.1.0
+    uses: numbata/danger-pr-comment/.github/workflows/danger-run.yml@v0.1.1
     secrets: inherit
     with:
       ruby-version: '3.4'

CHANGELOG.md

@@ -1,7 +1,8 @@
-### Next release
+### 1.1.1 (Next)
 
 #### Fixes
 
+* [#411](https://github.com/ruby-grape/grape-entity/pull/411): Fix CI on Ruby 3.0 (pin `json` below 3.0, `git` below 6, newer RuboCop directives), add Ruby 4.0 to the test matrix - [@numbata](https://github.com/numbata).
 * Your contribution here.
 
 #### Features

CONTRIBUTING.md

@@ -52,7 +52,7 @@ Document any external behavior in the [README](README.md).
 
 #### Update Changelog
 
-Add a line to [CHANGELOG](CHANGELOG.md) under *Next Release*. Make it look like every other line, including your name and link to your Github account.
+Add a line to [CHANGELOG](CHANGELOG.md) under the unreleased `(Next)` section. Make it look like every other line, including your name and link to your Github account.
 
 #### Commit Changes
 

Gemfile

@@ -6,13 +6,16 @@ gemspec
 
 group :development, :test do
   gem 'bundler'
+  # activesupport 7.1 (the newest on Ruby 3.0) passes `quirks_mode:` to JSON.generate, which json 3.0 removed
+  gem 'json', '< 3.0' if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('3.1')
   gem 'maruku'
+  gem 'ostruct' # no longer a default gem in Ruby 4.0
   gem 'pry' unless RUBY_PLATFORM.eql?('java') || RUBY_ENGINE.eql?('rbx')
   gem 'pry-byebug' unless RUBY_PLATFORM.eql?('java') || RUBY_ENGINE.eql?('rbx')
   gem 'rack-test'
   gem 'rake'
   gem 'rspec', '~> 3.9'
-  gem 'rubocop', '~> 1.0'
+  gem 'rubocop', '~> 1.90' # the disable-next directive needs 1.90
   gem 'yard'
 end
 
@@ -21,6 +24,8 @@ group :test do
   gem 'danger', require: false
   gem 'danger-changelog', require: false
   gem 'danger-pr-comment', require: false
+  # danger 9.6 references Git::Base, which git 6 no longer loads eagerly; drop once danger supports git 6
+  gem 'git', '< 6'
   gem 'growl'
   gem 'guard'
   gem 'guard-bundler'

RELEASING.md

@@ -19,7 +19,7 @@ Increment the version, modify [lib/grape-entity/version.rb](lib/grape-entity/ver
 *  Increment the third number if the release has bug fixes and/or very minor features, only (eg. change `0.5.1` to `0.5.2`).
 *  Increment the second number if the release contains major features or breaking API changes (eg. change `0.5.1` to `0.4.0`).
 
-Change "Next Release" in [CHANGELOG.md](CHANGELOG.md) to the new version.
+Change the "(Next)" heading in [CHANGELOG.md](CHANGELOG.md) to the new version and release date.
 
 ```
 0.4.0 (2014-01-27)
@@ -52,8 +52,13 @@ Pushed grape-entity 0.4.0 to rubygems.org.
 Add the next release to [CHANGELOG.md](CHANGELOG.md).
 
 ```
-Next Release
-============
+### X.Y.Z (Next)
+
+#### Fixes
+
+* Your contribution here.
+
+#### Features
 
 * Your contribution here.
 ```

lib/grape_entity/entity.rb

@@ -190,7 +190,7 @@ def self.inherited(subclass)
     #   field, typically the value is a hash with two fields, type and desc.
     # @option options :merge This option allows you to merge an exposed field to the root
     #
-    # rubocop:disable Layout/LineLength
+    # rubocop:disable-next Layout/LineLength
     def self.expose(*args, &block)
       options = merge_options(args.last.is_a?(Hash) ? args.pop : {})
 
@@ -217,7 +217,6 @@ def self.expose(*args, &block)
       @nesting_stack ||= []
       args.each { |attribute| build_exposure_for_attribute(attribute, @nesting_stack, options, block) }
     end
-    # rubocop:enable Layout/LineLength
 
     def self.build_exposure_for_attribute(attribute, nesting_stack, options, block)
       exposure_list = nesting_stack.empty? ? root_exposures : nesting_stack.last.nested_exposures

lib/grape_entity/exposure/nesting_exposure/nested_exposures.rb

@@ -36,7 +36,7 @@ def clear
             @exposures.clear
           end
 
-          # rubocop:disable Style/DocumentDynamicEvalDefinition
+          # rubocop:disable-next Style/DocumentDynamicEvalDefinition
           %i[
             each
             to_ary to_a
@@ -56,7 +56,6 @@ def #{name}(*args, &block)
               end
             RUBY
           end
-          # rubocop:enable Style/DocumentDynamicEvalDefinition
 
           # Determine if we have any nesting exposures with the same name.
           def deep_complex_nesting?(entity)

spec/grape_entity/entity_spec.rb

@@ -33,13 +33,12 @@
         end
 
         it 'makes sure that :format_with as a proc cannot be used with a block' do
-          # rubocop:disable Style/BlockDelimiters
+          # rubocop:disable-next Style/BlockDelimiters
           expect {
             subject.expose :name, format_with: proc {} do
               p 'hi'
             end
           }.to raise_error ArgumentError
-          # rubocop:enable Style/BlockDelimiters
         end
 
         it 'makes sure unknown options are not silently ignored' do
@@ -2294,12 +2293,11 @@ class FriendEntity < Grape::Entity
             end
           end
 
-          # rubocop:disable Lint/EmptyBlock
+          # rubocop:disable-next Lint/EmptyBlock
           fresh_class.class_eval do
             expose :first_friend, using: EntitySpec::FriendEntity do |_user, _opts|
             end
           end
-          # rubocop:enable Lint/EmptyBlock
 
           rep = subject.value_for(:first_friend)
           expect(rep).to be_kind_of EntitySpec::FriendEntity