Is there a reason to prefer mixed instead of void? Isn't void more precise since it's explicitly stating that the function doesn't return anything vs. mixed which would allow the function to return number, string, undefined, etc?

Yeah this is handled later in the stack

This was some feedback I got from @ashoat in D7643

This pattern of passing functions directly in instead of creating aliases is always easier if you type functions that take other functions as input (like useUploadSelectedMedia here) in a more permissive way, but letting them take any function that returns anything (mixed) instead of insisting that those functions return void specifically. In this case it didn’t matter because setState functions return void (see here) but it’s still a good pattern to follow.

if you type functions that take other functions as input (like useUploadSelectedMedia here) in a more permissive way

That makes sense, but this isn't a function that takes another function as input. Does that feedback still apply?

(CC @ashoat)

Yeah I think it still counts… a component taking props is similar to a function taking input

Imagine you want to pass an async function to onBlur. This forces you to wrap it in another function

If we don’t care about the result on onBlur, we should allow mixed

https://github.com/facebook/react-native/blob/main/packages/react-native/Libraries/Components/TextInput/TextInput.flow.js#L692

Gotcha, I'll update this diff w/ the changes.