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

machine.js

const pedestrianStates = {
  initial: 'walk',
  states: {
    walk: {
      on: {
        PED_COUNTDOWN: 'wait'
      }
    },
    wait: {
      on: {
        PED_COUNTDOWN: 'stop'
      }
    },
    stop: {},
    blinking: {}
  }
};

const lightMachine = Machine({
  key: 'light',
  initial: 'green',
  states: {
    green: {
      on: {
        TIMER: 'yellow'
      }
    },
    yellow: {
      on: {
        TIMER: 'red'
      }
    },
    red: {
      on: {
        TIMER: 'green'
      },
      ...pedestrianStates
    }
  },
  on: {
    POWER_OUTAGE: '.red.blinking',
    POWER_RESTORED: '.red'
  }
});