Gradle concept - Supporting JRuby + Gems

jruby-support.gradle

// This is just a concept - this code does not exist !!
// I have placed it here in order to facilitate discussion

// let's assume that we have specified the lcoation of the jruby
// plugin in buildscript {} block
apply plugin : 'jruby'

repositories {
  jcenter()
}

// ===============================================
// Specify jruby version
// We have two options
// ===============================================
// #1 - Use a version string. This will search the
//      repositories for 'org.ruby:jruby:${jRubyVersion}
jRubyVersion = '1.7.12'

// #2 - Use the standard dependency notation
//      The 'jruby' plugin will provide compile, testCompile
//      etc. if they have not already been provided by the 
//      'java' plugin.
//      Some additional thoughts required here. WHat if we
//      only need jruby during build-time, but not afterwards?
//
dependencies {
  compile 'org.ruby:jruby:1.7.12'
}

// ===============================================
// What about adding gems?
// ===============================================
// 'jruby' plugin will provide the 'gemXXX' extensions
// Gems will be downloaded to ~/.gradle/cache/jruby (or similar)
dependencies {
  // Gem is needed for compilation and will be packaged up as part
  // of artefact
  // NOTE the lack of groupID as gems do not have that concept AFAIK
  gemCompile 'erubis:2.7.0'
  
  // Gem is only needed during testing (thus will not be packaged )
  gemTestCompile 'erubis:2.7.0'
  
  // Gem is only needed for runtime and needs to be packaged as part
  // of artefact
  gemRunTime 'erubis:2.7.0'
  
  // Gem is needed as part of build, but not later on. 
  // Only passed to jrubyexec and JRubyExec
  gemExec 'erubus:2.7.0'
}

// ================================================
// What about adding repositories for finding gems?
// ================================================
// Obviously these will be needed :)
// 
repositories {
  rubygems { 
    name 'rubygems-release'
    url 'http://rubygems-proxy.torquebox.org/releases'
  }
  
  rubygems {
    name 'my-rubygems-on-bintray'
    url 'http://dl.bintray.com/myBintrayName/myBintrayGemRepo'
  }
}

// ================================================
// What if I need to execute a ruby script ?
// ================================================
// Let's provide a task for that as well as a
// project extension.
// Both cases will use the jruby provided via
// dependencies 
task runMyRubyScript( type : JRubyExec ) {
  script '/path/to/my/script.rb'
  args '-x', '-y', '-z'
  // rest of config follows much of JavaExec task
}

task myCustomTaskAlsoNeedsSomeRubyLove << {
  jrubyexec {
    // similar to task
  }
}