radio-blog-10.js

const radioChildContextTypes = {
   radioGroup: PropTypes.shape({
      onChange: PropTypes.function,
      value: PropTypes.string,
      name: PropTypes.string
   })
};

const getChildContext = props => ({
   radioGroup: {
      onChange: props.onChange,
      value: props.value,
      name: props.name
   }
})

export class RadioGroup extends React.Component { /* ... */}
export default withContext(radioChildContextTypes, getChildContext)(RadioGroup);

export class RadioOption extends React.Component { /* ... */}
export default getContext(getChildContext)(RadioOption);