My oldish .autotest (it's actually .autotest, but gist is teh lame)

autotest.rb

module RaggiGrowl      
  def self.growl title, msg, img = 'alert.png' , pri=0, stick="" 
    system "growlnotify -n autotest --image #{img} -p #{pri} -m #{msg.inspect} #{title} #{stick}"
    false
  end
  def self.dir; Dir.pwd; end
  def self.good; "~/Library/autotest/god.png"; end
  def self.bad; "~/Library/autotest/dead.png"; end

  SpecResults = /(\d+)\s+examples?,\s*(\d+)\s+failures?(,\s*(\d+)\s+pending)?/m
  TestUnitResults = /(\d+) tests, (\d+) assertions, (\d+) failures, (\d+) errors/m

  def self.setup
    Autotest.add_hook :ran_command do |autotest|
      next false unless autotest.results.size > 0

      failed = case
      when results = autotest.results.join("\n")[TestUnitResults]
        tests, assertions, failures, errors = $1, $2, $3, $4
        (failures.to_i + errors.to_i) > 0
      when results = autotest.results.join("\n")[SpecResults]
        tests, failures, pending = $1, $2, $3
        failures.to_i > 0
      else
        true
      end

      growl failed ? "Fail" : "Pass", results, failed ? bad : good
    end
  
    Autotest.add_hook :initialize do |att|
      growl "autotest", "starting up in #{dir}", good, 10
    end
  
    Autotest.add_hook :run do |at|
      growl "autotest", "running in #{dir}", good, 10
    end

    Autotest.add_hook :interrupt do |at|
      growl "autotest", "interrupted in #{dir}", bad, 10
    end

    Autotest.add_hook :quit do |at|
      growl "autotest", "quit in #{dir}", bad, 10
    end
  end
end

RaggiGrowl.setup

general_exceptions = [
  /^\.\/log/,
  /^\.\/doc/,
  /^\.\/script/,
  /^\.\/vendor/,
  /^\.\/public/,
  /^\.\/tmp/,
  /\.svn/,
  /\.git/
]

Autotest.add_hook :initialize do |att|
  att.testlib = 'minitest/autorun'

  def att.consolidate_failures(failed)
    filters = Hash.new { |h,k| h[k] = [] }

    failed.each do |test, klass|
      f = klass.gsub(/[a-z][A-Z]/) { |c| "#{c[0,1]}_#{c[-1,1]}" }
      f = f.downcase + '.rb'

      test_files = self.find_order.grep(Regexp.new(Regexp.escape(f)))

      warn "No mapping found for #{klass}##{test}" if test_files.empty?

      test_files.each do |test_file|
        filters[test_file] << test
      end
    end

    filters
  end
  
  general_exceptions.each do |except|
    att.add_exception except
  end

  att.add_mapping(%r%^test/test\.rb$%) do |filename, _|
    att.files_matching(%r%^test/.*test_.*\.rb$%)
  end

  # att.add_mapping(%r%^(test|spec)/(.*\.rb)$%) do |filename, _|
  #   fn = _.captures[1]
  #   dir = File.dirname(fn)
  #   file = File.basename(fn)
  #   file.sub!(/(test|spec)_/, '')
  #   puts "#{filename} => #{att.files_matching(%r%^lib/#{Regexp.escape dir}/#{Regexp.escape file}%)}"
  #   att.files_matching(%r%^lib/#{Regexp.escape dir}/#{Regexp.escape file}%)
  # end

  # att.add_mapping(%r%^lib/(.*\.rb)$%) do |filename, m|
  #   spec = File.basename(m[1], '.rb')
  #   path = File.dirname(m[1])
  #   [
  #     "test/#{path}/test_#{spec}.rb",
  #     "test/#{path}/spec_#{spec}.rb",
  #     "spec/#{path}/spec_#{spec}.rb",
  #     # TODO : decide if the follow 'rspec style' name should be allowed?
  #     "spec/#{path}/#{spec}_spec.rb",
  #     "spec/#{path}/#{spec}_test.rb"
  #   ]
  # end
end

dead.png

god.png

install

#!/usr/bin/env ruby

require 'fileutils'
include FileUtils
def ep(f)
  File.expand_path(f)
end
def inst(s, d, o = { :verbose => true })
  mkdir_p File.dirname(d)
  install s, d, o
end

inst 'autotest.rb', ep('~/.autotest'), :verbose => true
inst 'dead.png', ep('~/Library/autotest/dead.png'), :verbose => true
inst 'god.png', ep('~/Library/autotest/god.png'), :verbose => true