Generated by XState Viz: https://xstate.js.org/viz

machine.js

const connectionCheckerMachine = Machine({
  id: 'light',
  initial: 'green',
  states: {
    green: {
      on: {
        TIMER: 'yellow',
        WHATEVER: 'red'
      }
    },
    yellow: {
      on: {
        TIMER: 'red'
      }
    },
    red: {
      on: {
        TIMER: 'green'
      }
    }
  }
});