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

machine.js

const pong = Machine({
	id: 'pong',
	initial: 'started',
	states: {
		started: {
			on: {
				ping: { actions:  sendParent('pong', { delay: 1000}) },
			},
		},
	},
});

const ping = Machine({
	id: 'ping',
	initial: 'idle',
	context: {
		pong: null,
	},
	states: {
		idle: {
			on: {
				start: {
					target: 'ready',
					actions: assign({
						pong: () => spawn(pong),
					}),
				},
			},
		},
		ready: {
			on: {
				ping: {
					target: 'pinging',
					actions: send('ping', { to: (ctx) => ctx.pong }),
				},
			},
		},
		pinging: {
			on: {
				pong: 'ready',
			},
		},
	},
});