README Driven Development task for Rake

Rakefile

def code_from_markdown file
  content = File.read(file)
  code_snippets = []
  content.scan(/`{3,}ruby\n((.|\n)*?)^`{3,}/) { |m| code_snippets << $1 }
  code_snippets
end

namespace :test do
  # all code inside ```ruby ``` is executed to uncomment certain examples just
  # use ```xruby ``` or alike
  desc "Execute the codesamples in the README"
  task :codesamples do
    lib = File.expand_path("../lib", __FILE__)
    $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)

    examples = code_from_markdown("./README.md")
    examples.each do |example| 
      fork { eval example }
      Process.wait
    end
  end
end