function-expression-maybe-mutates-hook-return-value.js — react Source File

Source Code

function Component(props) {
  const id = useSelectedEntitytId();
  // this example should infer `id` as mutable, and then infer `onLoad` as mutable,
  // and be rejected because onLoad cannot be passed as a frozen value in the JSX.
  // however, we likely have to allow this example to work, because hook return
  // values are generally immutable in practice and are also widely referenced in
  // callbacks.
  const onLoad = () => {
    log(id);
  };
  return <Foo onLoad={onLoad} />;
}