import PropTypes from 'prop-types';
import exact from 'prop-types-exact';

function Foo({ foo, bar }) {
  return <div>{foo}{bar}</div>
}
Foo.propTypes = exact({
  foo: PropTypes.string,
  bar: PropTypes.number,
});

<Foo foo="hi" bar={3} /> // no warnings

<Foo foo="hi" bar={3} baz="extra" /> // propTypes warning!