Why isn't this action updating my array?

[river ravine]

Is this state set up properly? It seems to trigger the action but I can't get it to actually update the relevant array in context.

          entry: ["promptAttack"],
          on: {
            ATTACK: {
              actions: ["addCardToPlayingField"],
            },
          },
        },

promptAttack works

          return {
            ...context,
            playingField: [...context.playingField, event.card],
          };
        },

I can see this action being triggered, it has context and the right event. But playingField is never updated.

Any ideas on how to troubleshoot?

Why isn't this action updating my array?

[karmic ibex]

To update the context we have the assign action: https://stately.ai/docs/xstate/actions/context#assign-action

So your code could look something like this:

addCardToPlayingField: assign({
  playingField: (context, event) => [...context.playingField, event.card]
})