const newElem = {...[{}, {}], name: new Date().toString()}
const newList = elemList.slice();

  const [elemList, setElemList] = useState(getElemList);
  
  const getElemList = blockList.map((elem, index) => {
  const {name, id} = elem;
  const handleClick = () => {
    const newElem = {...elem, name: new Date().toString()}
    const newList = elemList.slice();
    newList[index] = newElem;
    setElemList(newList);
  }
    return (
      <div className="block-elem" key={id} onClick={handleClick}>
        { name }
      </div>
    )
  })