guard 'prove' do
# prove modified test file
watch(%r{^.*\.t$})
# prove all files in t directory when some module gets modified
# watch(%r{^.*\.pm$}) { "t" }
# prove path/t/file.t when path/file.pm gets modified
watch(%r{^(.*)/([^./]+)\.pm$}) {|m| m[1] + "/t/" + m[2] + ".t"}
end