next.js/examples/with-cerebral/modules/clock/signals.js

import { set } from 'cerebral/operators'
import { state, props } from 'cerebral/tags'
import { startTimer, stopTimer } from './actions'

export const mounted = [startTimer, set(state`clock.light`, true)]
export const unMounted = stopTimer
export const secondTicked = set(state`clock.lastUpdate`, props`now`)