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?

Comece pelo artigo vinculado “You Probably Don't Need Derived State” e pelo aviso de PropTypes relatado sobre o acesso a key. Determine se a documentação precisa de esclarecimentos sobre componentes totalmente não controlados com uma key; a tarefa estará concluída quando o artigo explicar uma mitigação válida ou documentar explicitamente a limitação.