Derived State: Fully uncontrolled component with a key

Hi,

In the article You Probably Don't Need Derived State, one of the recommended ways to avoid deriving state from props, is to have "Fully uncontrolled component with a key".

However, there is no way to actually force the user to provide a 'key' property to the component, since declaring it in propTypes as "key: PropTypes.any.isRequired" won't work, because it's value is always 'undefined', which leads to a warning message:

Warning: MyComponent: key is not a prop. Trying to access it will result in undefined being returned. If you need to access the same value within the child component, you should pass it as a different prop.

And without declaring the 'key' prop type, we cannot assume, that the user will use the component in a proper manner.

How to mitigate this?

Beginne mit dem verlinkten Artikel „You Probably Don't Need Derived State“ und der gemeldeten PropTypes-Warnung über den Zugriff auf key. Ermittle, ob die Dokumentation zu vollständig unkontrollierten Komponenten mit einem key einer Klarstellung bedarf; abgeschlossen ist die Aufgabe, wenn der Artikel eine gültige Abhilfe erklärt oder die Einschränkung ausdrücklich dokumentiert.