snippet.rb

require 'autotest/growl'
require 'autotest/timestamp'

Autotest::Growl::clear_terminal = false

Autotest.add_hook(:initialize) {|at|
  # at.clear_mappings         # take out the default (test/test*rb)

  # stop autotest from detecting changes in these files we don't care about
  %w{.git .svn .hg .swp .DS_Store ._* tmp db log tmp vendor rerun.txt Gemfile.lock}.each do |exception|
    at.add_exception(exception)
  end

  # add mapping for files test files that end in 'test'
  at.add_mapping(%r%^(test)/.*_test.rb$%) { |filename, _|
    filename
  }
  at.add_mapping(%r%^lib/(.*)\.rb$%) { |_, m|
    ["test/#{m[1]}_test.rb"]
  }

  # option to use for unit_diff
  at.unit_diff = "cat"
}

class Autotest
  # thinking of how to stop a full run unless specifically asked for
end