A note about not firing side effects in useState(prev => next) ?

So I ended up doing this by mistake after a wonky merge:

let Foo = (props) => {
    let [bar, setBar] = useState();
    
    let handleClick = () => {
        useState(bar => {
            let newBar = bar + 1;
            props.handleBarChange(newBar); // bad, which isn't surprising
            return newBar;
        });
    };

    return <div onClick={handleClick}>click me</div>;
};

If you fire a side effect such as calling something that sets state in a higher component from a useState updater function, you get the error "Cannot update a component from inside the function body of a different component" (but not always! It seems to depend on internal timing). This definitely seems like a bad idea when you look at it, but I couldn't find any mention in the docs that this is bad.

https://reactjs.org/docs/hooks-reference.html#functional-updates

There is the note about side effects generally on useEffect:

Mutations, subscriptions, timers, logging, and other side effects are not allowed inside the main body of a function component (referred to as React’s render phase)

But this is not in the main body of a function component, doesn't feel like a true side effect as it's still just setting state within React, and doesn't feel like it's in the render phase either.

I initially wanted to comment about this here (https://github.com/facebook/react/issues/18178), because the general message of that thread was "don't set state of another component in a render method", and I've managed to get this error message without doing that, but the thread is locked. Thanks.

リンクされたHooksリファレンスページ、特に関数型更新のセクションから始め、そこにあるガイダンスを、引用されているuseEffectの副作用に関する注記と比較してください。useStateのupdater内の副作用がサポートされていないのかを明確にし、関連する動作を説明してください。ドキュメントがこの例を曖昧さなく扱えば完了です。