Unfortunately, it seems that Machinist in cooperation with Active Record somehow bypasses dirty tracking. While I have test based on after_save callback, the tracked attribute must be set explicitely, otherwise tracked_changed? returns false... Does someone have experience with this?
# in after_save tracked_changed? returns false
client = Client.make!(:tracked => "AAA")
# in after_save tracked_changed? returns true
client = Client.make!
client.tracked = "XXX"
client.save