module RSpec::Matchers::Pretty

def underscore(camel_cased_word)
  word = camel_cased_word.to_s.dup
  word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
  word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
  word.tr!("-", "_")
  word.downcase!
  word
end