Throw exception on the wrong event

[chirillkirkin]

What if state machine will throw an exception when we try to do transition to some state by undeclared event (sorry for my english).
For example:
declaring state machine behaviour

initialState(State.SomeState)
state<State.SomeState> {
            on<Event.SomeEvent> {
                transitionTo(State.AnotherState, SideEffect.SomeSideEffect)
            }
}

then we trying to do undeclared transition (from state "SomeState")
stateMachine.transition(Event.SomeOtherEvent) //<- there is should be thrown an exception

[zhxnlai]

@Keyrillanskiy Currently, when that happens (undeclared event), it returns a Transition.Invalid object. Does that work for you?

[chirillkirkin]

@zhxnlai Just in my opinion, when FSM doing something wrong, there is should be an exception ¯_(ツ)_/¯