CI: Test with Ruby 4.0.0 (sinatra#2136)

Allow newer commonmarker to be used in CI as 0.23.10 can't be used with Ruby 4:
https://rubygems.org/gems/commonmarker/versions/0.23.10

For now, we need to use Bundler 2 when running the tests 
(Ruby 4 ships with Bundler 4 as the default): sinatra#2135

Author: dentarg

.github/workflows/test.yml

@@ -89,29 +89,33 @@ jobs:
           - "3.2"
           - "3.3"
           - "3.4"
+        bundler:
+          - default
         rubyopt:
           - "--enable-frozen-string-literal --debug-frozen-string-literal"
         include:
+          # Avoid Bundler 4 for now: https://github.com/sinatra/sinatra/issues/2135
+          - { ruby: "4.0", bundler: 2.7.2, rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
           # Rack
-          - { ruby: 3.4, rack: "~>3.0.0", puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
-          - { ruby: 3.4, rack: "~>3.1.0", puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
-          - { ruby: 3.4, rack: head, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: "~>3.0.0", puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: "~>3.1.0", puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: head, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable }
           # Rack::Session
-          - { ruby: 3.4, rack: stable, puma: stable, tilt: stable, rack_session: head, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: stable, puma: stable, tilt: stable, rack_session: head, zeitwerk: stable }
           # Puma
-          - { ruby: 3.4, rack: stable, puma: head, tilt: stable, rack_session: stable, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: stable, puma: head, tilt: stable, rack_session: stable, zeitwerk: stable }
           # Tilt
-          - { ruby: 3.4, rack: stable, puma: stable, tilt: head, rack_session: stable, zeitwerk: stable }
+          - { ruby: 3.4, bundler: default, rack: stable, puma: stable, tilt: head, rack_session: stable, zeitwerk: stable }
           # Test Zeitwerk < 2.7.0 separately
-          - { ruby: 3.4, rack: stable, puma: stable, tilt: head, rack_session: stable, zeitwerk: '<2.7.0' }
+          - { ruby: 3.4, bundler: default, rack: stable, puma: stable, tilt: head, rack_session: stable, zeitwerk: '<2.7.0' }
           # JRuby, tests are notable flaky
-          - { ruby: jruby,            rubyopt: "", rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
+          - { ruby: jruby,            bundler: default, rubyopt: "", rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
           # Never fail our build due to problems with head rubies
-          - { ruby: ruby-head,        rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
-          - { ruby: jruby-head,       rubyopt: "", rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
-          - { ruby: truffleruby-head, rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
+          - { ruby: ruby-head,        bundler: 2.7.2,   rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
+          - { ruby: jruby-head,       bundler: default, rubyopt: "", rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
+          - { ruby: truffleruby-head, bundler: default, rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
           # truffleruby 24.1 fails, see https://github.com/oracle/truffleruby/issues/3788
-          - { ruby: truffleruby,      rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
+          - { ruby: truffleruby,      bundler: default, rack: stable, puma: stable, tilt: stable, rack_session: stable, zeitwerk: stable, allow-failure: true }
 
     env:
       rack: ${{ matrix.rack }}
@@ -141,11 +145,21 @@ jobs:
       id: setup-ruby
       with:
         ruby-version: ${{ matrix.ruby }}
+        bundler: ${{ matrix.bundler }}
         bundler-cache: true
         # Update rubygems due to https://github.com/rubygems/rubygems/pull/6490 (3.0)
         # and https://github.com/sinatra/sinatra/issues/2051 (3.1)
         rubygems: ${{ matrix.ruby == '3.0' && 'latest' || matrix.ruby == '3.1' && 'latest' || 'default' }}
 
+    # workaround for https://github.com/ruby/setup-ruby/issues/845
+    - name: Ensure Gemfile.lock is created with Bundler 2 for Ruby 4
+      if: matrix.ruby == '4.0' || matrix.ruby == 'ruby-head'
+      run: |
+        rm Gemfile.lock
+        bundle install
+      env:
+        BUNDLER_VERSION: ${{ matrix.bundler }}
+
     - name: Run sinatra tests
       continue-on-error: ${{ matrix.allow-failure || false }}
       id: tests

Gemfile

@@ -37,7 +37,6 @@ gem 'sinatra-contrib', path: 'sinatra-contrib'
 gem 'asciidoctor'
 gem 'builder'
 gem 'childprocess', '>= 5'
-gem 'commonmarker', '~> 0.23.4', platforms: [:ruby]
 gem 'erubi'
 gem 'eventmachine'
 gem 'falcon', '~> 0.40', platforms: [:ruby]
@@ -64,3 +63,7 @@ gem 'webrick'
 java    = %w(jruby truffleruby).include?(RUBY_ENGINE)
 aarch64 = RbConfig::CONFIG["target_cpu"] == 'aarch64'
 gem 'sass-embedded', '~> 1.54' unless java && aarch64
+
+# jruby does not support native extensions
+# https://github.com/truffleruby/truffleruby/issues/3396#issuecomment-3694252552
+gem 'commonmarker' unless java

test/markdown_test.rb

@@ -14,6 +14,11 @@ def setup
     super
   end
 
+  # commonmarker is not installed on all platforms (e.g. jruby)
+  def commonmarker_v1_or_higher?
+    defined?(CommonMarkerTest) && self.class == CommonMarkerTest && defined?(::Commonmarker)
+  end
+
   it 'uses the correct engine' do
     assert_equal engine, Tilt[:md]
     assert_equal engine, Tilt[:mkd]
@@ -23,13 +28,22 @@ def setup
   it 'renders inline markdown strings' do
     markdown_app { markdown '# Hiya' }
     assert ok?
-    assert_like "<h1>Hiya</h1>\n", body
+    if commonmarker_v1_or_higher?
+      assert_equal "<h1><a href=\"#hiya\" aria-hidden=\"true\" class=\"anchor\" id=\"hiya\"></a>Hiya</h1>\n", body
+    else
+      assert_like "<h1>Hiya</h1>\n", body
+    end
   end
 
   it 'renders .markdown files in views path' do
     markdown_app { markdown :hello }
     assert ok?
-    assert_like "<h1>Hello From Markdown</h1>", body
+    if commonmarker_v1_or_higher?
+      assert_equal "<h1><a href=\"#hello-from-markdown\" aria-hidden=\"true\" " \
+                   "class=\"anchor\" id=\"hello-from-markdown\"></a>Hello From Markdown</h1>\n", body
+    else
+      assert_like "<h1>Hello From Markdown</h1>", body
+    end
   end
 
   it "raises error if template not found" do