React-Redux - Hooks API

Hooks are not compatible with Class components. To use Hooks, you convert the class components to function components. For instance, your code can be refactored to

/**
 *  Messages List
 */

const getActiveUser = (state: State) => state.activeUser;
const getMessagesList = (state : State) => (Object.keys(state.messages).map((key : any)=> state.messages[key]));

const MessagesList: React.FC = () => {
  const activeUser = useSelector(getActiveUser);
  const messagesList = useSelector(getMessagesList);

  ....
}

export default MessagesList;