class a {
  exec { "touch-foo":
        command         => "/bin/touch /tmp/foo",
        refreshonly     => true
  }
}
class b {
  file { "/tmp/config.txt":
    ensure => "present",
    content => "somestuff",
    notify => Exec["touch-foo"],
   }
}


include a
include b

% puppet test.pp
notice: //b/File[/tmp/config.txt]/ensure: content changed '{md5}dad7cdb0db24f8cf7ead6606b285903a' to '{md5}dad7cdb0db24f8cf7ead6606b285903a'
notice: //a/Exec[touch-foo]: Triggering 'refresh' from 1 dependencies