Should Obj-C completion handler wait for JS?

[holmesal]

On the Obj-C side, completion handlers are currently called immediately after the app event has been sent over the bridge. I haven't come up against any cases where this was disadvantageous, but I'm also not doing anything serious like fetching something over the network.

If this turns out the be a problem - an alternative implementation would be to store the obj-c completion handlers (no idea how to do this) by id, and pass that id over the bridge so that they can be invoked when the user calls done().