Panic on event Publishing

[joelschutz]

If you try to publish an Event that no handler is listening the program panic since no event bus is found.

How to Reproduce

Create a new event and try to publish to it.

type EnemyKilled struct {
	EnemyID int
}

var EnemyKilledEvent = events.NewEventType[*EnemyKilled]()

func TestEvents(t *testing.T) {
	w := donburi.NewWorld()
	EnemyKilledEvent.Publish(w, &EnemyKilled{EnemyID: 1})
}

Problem

It makes sense to only initialize a bus if there is a handler to react to it, but in a game you often need to add or remove subscribers dymanically. Attaching the bus initialization to the Subscribe method makes it difficult since all the system depends on that first subscription.

[yohamta]

Hi @joelschutz , Thank you so much for submitting such a great issue and PR! It has been released as version 1.3.7.