Hello Milosz,
as explained on IRC, the only available behavior (for the moment as I will send a patch soon), is to:
* send the command
* wait for any of the prompts or the defined patterns
* record the result (if asked by the test writer=a name is defined)
This is working like this because I was using it with the "bootloader" boot which does wait for the bootloader prompt before ending the action. So the interactive test was already at the prompt. This is what is usually done for most actions in LAVA.
I will add an options to wait before the action (or maybe just a specific command that will just wait for the prompt).
The most difficult task is (as usual) finding the right name for it :)
Thanks for testing and reporting issues!