Handling uninstallation upon subordinate removal in reactive

[Junien Fridrick]

Hi,

I'm developping a charm, and would like to know the best practive to
do some uninstallation steps when a subordinate gets removed from a
unit (these steps being : uninstall a snap)

The only way I can think of is to use @hook('stop'), but as far as I
remember, using hooks is not something one should do in the reactive
world.

Does anyone have any advice for doing that properly ?

I was also thinking that maybe the snap layer could save which
application installed which snap, and if said application is removed,
then remove said snap. Would that be a good idea ?

Thanks !