Let’s assume that I wrote this great utility that does this magnificent function that will help mankind. And this utility/software needs a computer to run. Now, I speak Ruby quite well – and specify my behavior thoroughly with RSpec. But alas – most computers don’t have ruby installed (Java JRE yes, Ruby no, especially in enterprises).

So let’s also assume that some giants wrote a Ruby interpreter that can run on a JVM, and called it JRuby. And further more assume that most java “utilities” can be written inside a single jar, and can be executed with:

java -jar fairy_dust.jar

How can I take my ruby code and have it run just like the above? With just a single file and all …

Answer:
1. JRuby
2. One-jar
3. Custom Bootstrapper

And the result is – a JAR file, with multiple Ruby files inside – that works just like a java jar:

java -jar rubified.jar

And you can get all the above (with the ant build.xml) for the price of one download!

Presenting: Rubified 0.1 BETA

A quick peek into ruby/bin/gem revealed much of what I needed to know.

Lets demonstrate :

Welcome to the JRuby IRB Console 

irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> Gem.manage_gems
=> true
irb(main):003:0> gem = Gem::GemRunner.new
=> #
irb(main):004:0> gem.run(['help','commands'])
GEM commands are:

    build            Build a gem from a gemspec
    cert             Adjust RubyGems certificate settings
    check            Check installed gems
    ...
=> nil
irb(main):005:0>

update: The bug that prevented me from installing gems, turned out to be a _gemrc file that had http_proxy configured. A proxy no longer in use, but since I didn’t use gems all that much on this workstation before – I forgot all about it.

This is what I came up with:

#!/bin/env ruby

exit if ARGV[0].nil?
exit unless File.exists?(ARGV[0])

CACHE_DIR_NAME='cache'

haml_file = ARGV[0]
haml_time = File.stat(haml_file).mtime

html_file = CACHE_DIR_NAME + '/' + haml_file.sub(/aml$/,'tml')
if File.exists?(html_file)
  html_time = File.stat(html_file).mtime

  if html_time > haml_time
    output = File.read(html_file)
  end
end

if output.nil?
  require 'rubygems'
  require 'haml'
  template = File.read(haml_file)
  haml_engine = Haml::Engine.new(template)
  output = haml_engine.to_html()

  # cache the output
  Dir.mkdir(CACHE_DIR_NAME) unless File.directory?(CACHE_DIR_NAME)
  html_file_io = File.open(html_file,"w")
  html_file_io.print(output)
  File.utime(Time.now, haml_time, html_file)
end

# unbuffer output
$stdout.sync = true

require 'cgi'
ENV['SERVER_SOFTWARE'] ||= 'not set'
cgi = CGI.new('html3')
print cgi.header(
        'type'     => 'text/html',
        'charset'  => 'UTF-8',
        'length'   => output.length,
        'server'   => ENV['SERVER_SOFTWARE'],
        'expires'  => Time.now + 10*3600*24, # 10 days
        'Pragma'   => 'no-cache',
        'Last-Modified' => haml_time,
        'Cache-Control' => 'no-cache'
)
print output

And as Mike suggested, adding a couple lines to your Apache configuration makes all the difference:

  AddType text/haml .haml
  AddHandler haml-file .haml
  Action haml-file /dev/bin/haml_cache_cgi.rb
  Action text/haml /dev/bin/haml_cache_cgi.rb

I want it to be more DRY than it is, since the whole application is using rSpec and Haml, all helpers should have the same before(:each)

So basically – what I did was :

[source:ruby]
Spec::Runner.configure do |config|
config.with_options :behaviour_type => :helpers do |config|
config.include Haml::Helpers
config.include ActionView::Helpers
config.prepend_before :all do
@haml_is_haml = true
@haml_stack = [Haml::Buffer.new]
end
end
end
[/source]

Except it will not work, for various reasons.

Hope to solve all the quirks sometime soon. I know this will cost me some sleep.

After months of reading and getting to know what test driven development and extreme programming is all about, I have finally been able to practice what I preach. Since I work with several programmers and the product we are writing is so new that it is still in diapers (famous hebrew saying). Quality control is a demand from above management, after they got burned with too many escalations with the existing product. So part of my job description was preaching unit testing and such.

Anyways – I really did understand and could quote all the reasons why testing is important, and why its a sort of a documentation, and why it should be done before coding, and why it makes coding more structured and disciplined and gives the programmer a direction. But I could not make myself understand how to implement it with ruby’s Test::Unit for example, not even talking about more obscure implementations of xUnit like CppUnit which is something that was chosen for our project.

Last week I saw the presentation Dave Astels made at google, freely downloadable from google video. An I saw that it was god (with one ‘o’). And today I finally got to trash all the beginnings that I tried to do with Test::Unit on the ClearCase wrapper I’m writing – and started doing rSpec instead.

It flowed… like a river. And any bumps that were on the were not frustrating, they were annoying, thus actually motivating me to kick them of my route and continue flowing with the flow without any frustration. It rocks. I love it.

Still the one thing I miss with all this TDD and BDD are good concrete examples that are a bit more than what rSpec examples are, I need it chewed and digested for extreme easy understanding. Maybe a step-by-step evolving kind of code, maybe even a book matching the Progmatic books quality is the thing missing in all of this. Because it always looks really great – but when a motivated but inexperienced programmer like me tries to implement this stuff it soon becomes frustrating. Even though rSpec is not too frustrating, and hopefully it will only grow to be easier and more intuitive and productive like it is already in its alpha(?) state.

Enough ramblings for now – back to the code!