jest/examples/snapshot/Clock.js

// Copyright (c) Meta Platforms, Inc. and affiliates.. All Rights Reserved.

import {useEffect, useState} from 'react';

export default function Clock() {
  const [seconds, setSeconds] = useState(Date.now() / 1000);

  const tick = () => {
    setSeconds(Date.now() / 1000);
  };

  useEffect(() => {
    const timerID = setInterval(() => tick(), 1000);

    return () => clearInterval(timerID);
  }, []);

  return <p>{seconds} seconds have elapsed since the UNIX epoch.</p>;
}