Relax required_ruby_version to support Ruby 4.0

[taketo1113]

This Pull Request relaxed the required_ruby_version to allow Ruby 4.0.

The current gemspec specifies an upper bound of < 4, which prevents gem install contracts from working on Ruby 4.0, scheduled for release on December 25.
By removing this upper bound, the gem will continue to work on Ruby 4.0 and future Ruby versions.

• Ruby 4.0.0 preview2 Released
  • https://www.ruby-lang.org/en/news/2025/11/17/ruby-4-0-0-preview2-released/

Additional Information

All tests pass on my local environment using Ruby 4.0-dev.

$ ruby -v
ruby 4.0.0dev (2025-11-28T10:49:46Z master dcb9e17f46) +PRISM [arm64-darwin25]

$ bundle exec rake spec
...
Finished in 0.06349 seconds (files took 0.0736 seconds to load)
231 examples, 0 failures

$ bundle exec rake cucumber
...
85 scenarios (1 undefined, 84 passed)
372 steps (372 passed)
0m9.122s

[PikachuEXE]

Also .github/workflows/tests.yaml should be updated to add 4.0 (it should pick up beta?)

[taketo1113]

@PikachuEXE I have updated required_ruby_version and added Ruby 4.0 to the CI matrix.
(Since the CI will use the latest available Ruby 4.0 version when it runs, I don't think any manual pick-up is necessary.)

However, bundle exec cucumber is failing in the CI on my forked repository, so I will look into the cause.
https://github.com/taketo1113/contracts.ruby/actions/runs/19799663868/job/56725105155

[taketo1113]

However, bundle exec cucumber is failing in the CI on my forked repository, so I will look into the cause.
https://github.com/taketo1113/contracts.ruby/actions/runs/19799663868/job/56725105155

The CI was failing because the aruba gem dependency includes a bundler < 3.0 constraint, causing an older version of aruba to be used on Ruby 4.0.
This dependency issue has already been fixed in the following PR, so it should be resolved in the next release of the aruba gem.

• Remove bundler version upper limit constraint cucumber/aruba#962

https://github.com/taketo1113/contracts.ruby/actions/runs/19799663868/job/56725105155#step:3:49

      archive-tar-minitar (0.12)
        minitar (~> 0.12)
        minitar-cli (~> 0.12)
# when use ruby 4.0-preview2: test fail
+      aruba (0.14.14)
+        childprocess (>= 0.6.3, < 4.0.0)
+        contracts (~> 0.9)
+        cucumber (>= 1.3.19)
+        ffi (~> 1.9)
+        rspec-expectations (>= 2.99)
+        thor (>= 0.19, < 2.0)
# use ruby 3.4.7: test pass
-      aruba (2.3.2)
-        bundler (>= 1.17, < 3.0)
-        contracts (>= 0.16.0, < 0.18.0)
-        cucumber (>= 8.0, < 11.0)
-        rspec-expectations (>= 3.4, < 5.0)
-        thor (~> 1.0)
      ast (2.4.3)

[PikachuEXE]

Thx for checking
I've subscribe to https://github.com/cucumber/aruba release so when there is a new version I will come back and let workflow run... (or maybe I will test locally first

[taketo1113]

Since aruba gem v2.3.3 has been released, I believe the CI should now pass.
When you have a moment, could you please take a look?

• https://github.com/cucumber/aruba/releases/tag/v2.3.3

[PikachuEXE]

Oh I am not an owner
Need to wait for @egonSchiele to release

[taketo1113]

Thank you for merging it!

[egonSchiele]

pushed thanks all

[PikachuEXE]

Added missing tag v0.17.3

[egonSchiele]

Fun I always forget git push doesn't push tags. Thanks!

[PikachuEXE]

I usually use SourceTree with option to push
Or just gem-release (commit manually but release + push tag via command)