What is the reason for the prop-types typecheck error?

Question

React

There is a simple code:

import PropTypes from 'prop-types';

const UsersList = props => (
    <div className="container">
        {props.loading ? '1' : '2'}
    </div>
);

UsersList.propTypes = {
    loading: PropTypes.bool()
};

Error in console:

Calling PropTypes validators directly is not supported by the `prop-types` package. Use `PropTypes.checkPropTypes()` to call them. Read more at fb.me/use-check-prop-types

I followed the link, but I didn’t understand anything: what does he need? Why call checkPropTypes? Why doesn't the perfectly typical and primitive case work?

Answer 1

The typical and primitive case is described as follows:

UsersList.propTypes = {
    loading: PropTypes.bool
};