homer.rb

require 'logger'

module Puppet::Parser::Functions
  newfunction(:homer, :type => :rvalue) do |args|

    log = Logger.new(STDOUT)
    log.level = Logger::INFO

    log.info("this going into logs on SERVER: #{args[0]}")

    raise(Puppet::ParseError, "this raise an error on CLIENT by 'puppet agent -t' : #{args[0]}")

    "some string return"
  end
end