worker js in react code example

Example: react web worker

import {    IonContent,    IonPage,    IonLabel,    IonButton} from '@ionic/react';import React, {useState} from 'react';import {RouteComponentProps} from 'react-router';import './Page.css';const Page: React.FC<RouteComponentProps<{ name: string; }>> = ({match}) => {    const [countTomato, setCountTomato] = useState<number>(0);    const [countApple, setCountApple] = useState<number>(0);    function incApple() {        const start = Date.now();        while (Date.now() < start + 5000) {        }        setCountApple(countApple + 1);    }    return (        <IonPage>            <IonContent className="ion-padding">                <IonLabel>Tomato: {countTomato} | Apple: {countApple}</IonLabel>                <div className="ion-padding-top">                    <IonButton                      onClick={() => setCountTomato(countTomato + 1)}                     color="primary">Tomato</IonButton>                                        <IonButton                      onClick={() => incApple()}                      color="secondary">Apple</IonButton>                </div>            </IonContent>        </IonPage>    );};export default Page;