Use built-in jruby parser when running jruby

.gitlab-ci.yml

@@ -54,7 +54,7 @@ jruby_1.7:
     - master
   script:
     - ruby -v
-    - JRUBY_OPTS="-J-Djruby.launch.inproc=true" ruby scheck.rb
+    - ruby scheck.rb --jruby
 
 jruby_9.1:
   image: jruby:9.1
@@ -65,7 +65,7 @@ jruby_9.1:
     - master
   script:
     - ruby -v
-    - JRUBY_OPTS="-J-Djruby.launch.inproc=true" ruby scheck.rb
+    - ruby scheck.rb --jruby
 
 rubocop:
   stage: linting

scheck.rb

 #!/usr/bin/env ruby
 
-ret = 0
+jruby = ARGV.length == 1
+ret   = 0
+
+require 'jruby' if jruby
+
 Dir["**/*.rb"].each do |f|
-  res = `ruby -c #{f}`
+  res = String.new  
+  if jruby
+    begin
+      JRuby.parse(File.read(f))
+      res = 'Syntax OK'
+    rescue SyntaxError => e
+      puts e.to_s
+    end
+  else
+    res = `ruby -c #{f}`
+  end
+
   if res.empty?
     ret = 1
     puts "#{f} FAILED!"