Ruby 4.0.0 Released | Ruby

Ruby Box is a new (experimental) feature to provide separation about definitions. Ruby Box is enabled when an environment variable RUBY_BOX=1 is specified. The class is Ruby::Box. Definitions loaded in a box are isolated in the box. Ruby Box can isolate/separate monkey patches, changes of global/class variables, class/module definitions, and loaded native/ruby libraries from other boxes. Expected use cases are: Run test cases in box to protect other tests when the test case uses monkey patches to override something Run web app boxes in parallel to execute blue-green deployment on an app server in a Ruby process Run web app boxes in parallel to evaluate dependency updates for a certain period of time by checking response diff using Ruby code Used as the foundation (low-level) API to implement kind of “package” (high-level) API (it is not designed yet).