Expose { state } in meta arg for built-in actions

[hackape]

When using custom declarative actions, I can access the current state from meta.state passed to exec(context, event, meta) function. But I cannot do the same with built-in action creators like actions.pure((context, event, meta) => { /* ... */ }).

I hope the same meta object with state can be exposed to built-in actions.

Use case

"log" action is triggered at entry of each state node. Within the action I want to send the current state of this machine to other party of interest. So I need to use action.pure to dynamically generate action.send. Currently there's no way to achieve this effect.

Machine({
  states: {
    green: { entry: "log", on: { TICK: "yellow" } },
    yellow: { entry: "log", on: { TICK: "red" } },
    red: { entry: "log", on: { TICK: "green" } },
  } 
}, {
  actions: {
    log: actions.pure((context, event, meta) => {
      if (Array.isArray(context.subscribers)) {
        return context.subscribers.map(id => 
          actions.send({ type: 'REPORT_CURRENT_STATE', payload: meta.state.value }, { to: id })
        )
      }
      return undefined
    })
  }
})