Investigate what happens when events sender is not configured

[mversic]

This piece of code in core/src/wsv.rs should be investigated:

    fn produce_events(&self, events: impl IntoIterator<Item = DataEvent>) {
        let events = events.into_iter().map(Event::from);
        let events_sender = if let Some(sender) = &self.events_sender {
            sender
        } else {
            return warn!("wsv does not equip an events sender");
        };
        for event in events {
            drop(events_sender.send(event))
        }
    }

I can't say why this compiles, maybe it panics inside the macro. Probably an error should be returned or events just dropped

[Erigara]

As far as i can see warn! doesn't panic inside, when i try to call produce_event on default WorldStateView where events_sender is None (see following snippet) and read through macro expanded version of produce_event function i don't notice anything suspicious.

It seems like event is just discarded if events_sender is None.

  #[test]
  fn produce_event_none_events_sender() {
      let block = ValidBlock::new_dummy().commit();
      let wsv = WorldStateView::<World>::default();
      let event = wsv.create_time_event(&block).unwrap();
      wsv.produce_event(event);
  }

I can't say why this compiles

@mversic Could you please explain why it shouldn't compile.

[mversic]

ok, I was confused by the return statement. It's all good here

[Erigara]

Maybe to avoid confusion we could refactor produce_event to something like this?

  /// Send [`Event`]s to known subscribers.
  fn produce_event(&self, event: impl Into<Event>) {
      if let Some(events_sender) = &self.events_sender {
          drop(events_sender.send(event.into()));
      } else {
          warn!("wsv does not equip an events sender");
      }
  }

[mversic]

Yeah, if you wish