assuming your LV does crash then on JavaScript side doing this

liveSocket.channel.onError(thing)

should get you a trigger that works

I understand that the best approach is to produce bugs free code and expect all possible outcomes from functions. But bugs happen. Things go wrong. Not all things are as simple as Repo.update. There is always a lag between error reported and error fixed during which users face the error.

Seeing 500 page is no good. But even worse is not seeing it when something went wrong because then user has no idea if a function worked or not.

What I don’t understand is that exceptions on mount are caught and converted to an exception page by Phoenix error views - pretty much like the way it works with controllers - quote from LV docs. But exceptions on handle_event are not converted to error view. So if exception happens on mount - the user knows that there is a server error. If exception happens after a button click - the user is unaware, because the page stays the same.

def already supports the following form:

def handle_event("event", args, socket) do
  # whatever
rescue
 e ->
  # handle exception here
end

This lets you skip the boilerplate of an additional try do end