Strange behaviour for setStage and setActivePlayers for Stage.NULL

[evandroabukamel]

Hey guys, what's up? I have a question about using the Stage.NULL. In the docs it's said that players can become active but in no stage if we set them to Stage.NULL using setActivePlayers.

What I'm trying to achieve is to make all players to use a specific move from no stage but when they make some moves from specific stages they must exit that stage but still become active. So, I'm trying to keep all other players in the same state they are when players calls a move that should put themselves to Stage.NULL. Now, everybody receive a "player not active" error. So I try a few things:

1. Using setStage(Stage.NULL) at the end of a move: by doing this, the player was removed from activePlayers property, thus becoming inactive.

2. Using setActivePlayers([ctx.playerID]) at the end of a move: by doing this, only that player becomes active in Stage.NULL and all other players are removed from activePlayers property.

So, am I doing something wrong or is there a bug in one of those functions?
What you suggest me to do? I was thinking of merge the current ctx.activePlayers with setActivePlayers parameter, but I think this is very risky. Don't know.

Thanks.

[delucis]

setActivePlayers overwrites the entire state, so yes, one way to set just one player, would be to spread the existing state in:

function onMove(G, ctx) {
  ctx.events.setActivePlayers({
    value: {
      ...ctx.activePlayers,
      [ctx.playerID]: Stage.NULL,
    }
  });
}

That isn’t really risky, but setActivePlayers does reset move counts etc., which may be undesirable.

More importantly, setStage(Stage.NULL) should work. My guess would be there’s a check somewhere that does if (arg) instead of if (arg || arg === Stage.NULL), probably these two:

boardgame.io/src/core/flow.ts

Lines 559 to 567 in 5d34610

	if (!arg && playerInStage) {
	const conf = GetPhase(ctx);
	const stage = conf.turn.stages[activePlayers[playerID]];
	if (stage && stage.next) arg = stage.next;
	}
	if (next && arg) {
	next.push({ fn: UpdateStage, arg, playerID });
	}

Would you like to fix that and add a test for setStage(Stage.NULL)?

[evandroabukamel]

Sure, I'll do that. I've also tried that with a unit test and found that bug.

[evandroabukamel]

@delucis , can I solve #777 too? I believe I found it's code here and it's very simple to fix.

---- EDIT
I've tried that and many tests broke. Maybe I can work on that later.

[delucis]

can I solve #777 too?

I'm not sure I think #777 is so helpful either. We have to check that active players is empty quite often which would become something like Object.keys(ctx.activePlayers).length === 0, which is also not a great experience.