`Done` component added inside `observer` with `OnAdd` a state are never read by `done()` trigger

[scorsi]

Hi,

Title self-explanatory about the bug.

Here's a 100% repro:

use bevy::prelude::*;
use seldom_state::prelude::*;

fn main() {
    App::new()
        .add_plugins((DefaultPlugins, StateMachinePlugin::default()))
        .add_systems(Startup, startup)
        .add_observer(observer)
        .run();
}

#[derive(Component, Copy, Clone)]
struct Init;

#[derive(Component, Copy, Clone)]
struct Ready;

#[derive(Component, Copy, Clone)]
struct Working;

#[derive(Component, Copy, Clone)]
struct NotWorking;

fn startup(mut commands: Commands) {
    commands.spawn((
        StateMachine::default()
            .trans::<Init, _>(
                move |In(_): In<Entity>, time: Res<Time>| {
                    if time.elapsed_secs() >= 5.0 { // In order to repro the bug, the state should be added later not instant
                        Ok(())
                    } else {
                        Err(())
                    }
                },
                Ready,
            )
            .trans::<Ready, _>(done(Some(Done::Success)), Working)
            .trans::<Ready, _>(done(Some(Done::Failure)), NotWorking)
            .set_trans_logging(true),
        Init,
    ));
}

fn observer(trigger: Trigger<OnAdd, Ready>, mut commands: Commands) {
    dbg!("add Done::Success");
    commands.entity(trigger.target()).insert(Done::Success);
}

2025-07-05T18:56:31.110834Z  INFO bevy_winit::system: Creating new window App (0v1)
[src\main.rs:45:5] "add Done::Success" = "add Done::Success"
2025-07-05T18:56:36.176137Z  INFO seldom_state::machine: 8v1#4294967304 transitioned from bug_repro::Init to bug_repro::Ready
2025-07-05T18:56:41.420285Z  INFO bevy_window::system: No windows are open, exiting    
2025-07-05T18:56:41.421504Z  INFO bevy_winit::system: Closing window 0v1

It seems that the Done is added before the StateMachine see the transition and thus get cleaned before being read by the correct trigger... and so I soft-lock the game.
Do you have any ideas?

(I managed it with my own components for Done/Failure and own cleanup mechanism, so that's not an urgent matter)

Thanks,

[scorsi]

There's the same behaviour when a Done is set from a (command_)on_enter(_to) hook.

The more I think about that, the more I wonder if this is not because the StateMachine when moving to a new state, should immediately check for the next one?