XState state.exit.actions & micro transitions will be executed in the next state

[huan]

If the action is sensitive to the current state, then a workaround will be needed.

For example:

createMachine({
  states: {
    idle: {},
    busy: {
      always: {
        10: 'idle',
      },
      exit: {
        actions: [
          Mailbox.actions.send(...), // <- this will be executed with state `idle`
        ],
      },
    },
  },
})

In the above code, the Mailbox.actions.send(...) will be executed within the state idle, instead of in the state busy.

Related discussion:

• XState state.exit.actions & micro transitions will be executed in the next state? statelyai/xstate#3231

[huan]

Due to the above behavior, I have to react to the ACTOR_REPLY event in both idle and busy states:

mailbox/src/impls/wrap.ts

Lines 159 to 176 in 50a2ca5

	[duck.Type.ACTOR_REPLY]: {
	actions: [
	actions.log<context.Context, duck.Event['ACTOR_REPLY']>(
	(ctx, e, { _event }) => [
	'states.Idle.on.ACTOR_REPLY [',
	e.payload.message.type,
	']@',
	_event.origin,
	' -> [',
	context.request.type(ctx),
	']@',
	context.request.address(ctx),
	].join(''),
	MAILBOX_ADDRESS_NAME,
	),
	context.sendChildResponse(MAILBOX_ADDRESS_NAME),
	],
	},

That's because if an actor(child) machine calls the Mailbox.actions.reply(e) in an exit entry and then transitions to idle, then the ACTOR_REPLY event will be sent to the Mailbox in its idle state (instead of busy)