forbid-foreign-prop-types: Allow setting propTypes

To use PropTypes.instanceOf and avoid circular dependencies I need to set propTypes outside of the “target” component. However forbid-foreign-prop-types kicks in.

const PropTypes = require(`prop-types`);
const React = require(`react`);

const B = require(`./B`);

class A extends React.Component {
	render(){
		return <B me={this} />;
	}
}

B.propTypes.prop = PropTypes.instanceOf(A).isRequired;

module.exports = A;

[DimitarNestorov]

Actually I don’t think passing a component instance to a child is a good practice. I’m even thinking of a rule that throws when such behaviour is present.

Switching to PropTypes.shape and closing.

[ljharb]

If B is requireable, then it’s just as exposed as A 😃 However, if you’re going to have circular dependencies - something you should avoid strenuously - you can’t use the otherwise best practice of module.exports =. Do exports.A = A; and exports.B = B, and then your circular dependencies will work fine.