CI: let's roll tests with JRuby

.github/workflows/test.yml

@@ -14,8 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
-        # TODO: Add jruby if something like allow_failures will be implemented on Actions.
-        ruby: [2.6, 2.7, '3.0', 3.1]
+        ruby: [2.6, 2.7, '3.0', 3.1, 'jruby-9.3']
     steps:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1

test/integration_helper.rb

@@ -105,59 +105,7 @@ def run_test(target, &block)
     end
   end
 
-  if RUBY_ENGINE == "jruby"
-    class JRubyServer < BaseServer
-      def start_vm
-        require 'java'
-        # Create a new container, set load paths and env
-        # SINGLETHREAD means create a new runtime
-        vm = org.jruby.embed.ScriptingContainer.new(org.jruby.embed.LocalContextScope::SINGLETHREAD)
-        vm.load_paths = [File.expand_path('../lib', __dir__)]
-        vm.environment = ENV.merge('APP_ENV' => environment.to_s)
-
-        # This ensures processing of RUBYOPT which activates Bundler
-        vm.provider.ruby_instance_config.process_arguments []
-        vm.argv = ['-s', server.to_s, '-o', '127.0.0.1', '-p', port.to_s, '-e', environment.to_s]
-
-        # Set stdout/stderr so we can retrieve log
-        @pipe = java.io.ByteArrayOutputStream.new
-        vm.output = java.io.PrintStream.new(@pipe)
-        vm.error  = java.io.PrintStream.new(@pipe)
-
-        Thread.new do
-          # Hack to ensure that Kernel#caller has the same info as
-          # when run from command-line, for Sinatra::Application.app_file.
-          # Also, line numbers are zero-based in JRuby's parser
-          vm.provider.runtime.current_context.set_file_and_line(app_file, 0)
-          # Run the app
-          vm.run_scriptlet org.jruby.embed.PathType::ABSOLUTE, app_file
-          # terminate launches at_exit hooks which start server
-          vm.terminate
-        end
-      end
-
-      def run
-        return unless installed?
-        kill
-        @thread  = start_vm
-        @started = Time.now
-        warn "#{server} up and running on port #{port}" if ping
-        at_exit { kill }
-      end
-
-      def log
-        String.from_java_bytes @pipe.to_byte_array
-      end
-
-      def kill
-        @thread.kill if @thread
-        @thread = nil
-      end
-    end
-    Server = JRubyServer
-  else
-    Server = BaseServer
-  end
+  Server = BaseServer
 
   def it(message, &block)
     Server.each do |server|