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

machine.js

const timerMachine = Machine({
  id: 'timer',
  context: {
    duration: 1000,
    otherThing: 'hey'
  },
  initial: 'test',
  states: {
    test: {
      entry: context => console.log('context:', context)
    }
  }
});

const parentMachine = Machine({
  id: 'parent',
  initial: 'active',
  context: {
    customDuration: 3000
  },
  states: {
    active: {
      invoke: {
        id: 'timer',
        src: timerMachine,
        data: {
          duration: (context, event) => context.customDuration
        }
      }
    }
  }
});