const Hello = () => <span id="hello-span">hello</span>; const World = () => ( <div id="world-root"> <div id="world-parent-div"> <span id="world-parent-span"> <Hello id="hello-component" /> </span> </div> <h2 id="world-h2">world</h2> </div> ); return ( <div id="r"> <World id="world-component" /> </div> );