Trigger Actions When Entering and Exiting a XState State

Actions aren't limited to being called on transitions. They can also be called when we enter or exit a state node. This is done through the entry and exit properties.

The API for entry and exit actions is the same as that for actions on transitions. It can receive a single function or an array of functions, each which will be called with the next context and the event object that caused the transition.

This is a powerful way to fire side effects based on states rather than transitions.

//...
states: {
  broken: {
    entry: [
      (context, event) => {
        sideEffectToFireWhenWeEnterTheBrokenState(context, event)
      }
    ],
    exit: [
      (context, event) => {
        sideEffectToFireWhenWeExitTheBrokenState(context, event)
      }
    ]
  }
}