unwrap returns inconsistent values when async atom resolves

[koutaro-masaki]

Bug Description

Since v2.10, when an async atom resolves, different unwrap atoms may show inconsistent values at the same moment. Specifically, a globally defined unwrappedAtom may return undefined even though the same async atom has already resolved and another unwrap instance has received the value. This behavior did not occur in v2.9.

Reproduction Code

import { atom, useAtomValue } from 'jotai';
import { unwrap } from 'jotai/utils';
import { Suspense, useMemo } from 'react';

const asyncDataAtom = atom(async () => {
  await new Promise((resolve) => setTimeout(resolve, 1000));
  return { data: 'Hello, World!' };
});
const unwrappedAtom = unwrap(asyncDataAtom, (prev) => prev);

const useTriggerAsync = (anAtom) => {
  const triggerAtom = useMemo(
    () => atom((get) => (get(unwrap(anAtom)) ? null : get(anAtom))),
    [anAtom]
  );
  useAtomValue(triggerAtom);
};

const DataTrigger = ({ children }) => {
  useTriggerAsync(asyncDataAtom);
  return children;
};

const DataDisplay = () => {
  const data = useAtomValue(unwrappedAtom);
  console.log('unwrappedAtom result:', data);
  return <div>Data: {data?.data}</div>;
};

export default function App() {
  return (
    <div>
      <Suspense fallback={<div>Loading...</div>}>
        <DataTrigger>
          <DataDisplay />
        </DataTrigger>
      </Suspense>
    </div>
  );
}

Expected Behavior

The console should never show unwrappedAtom result: undefined.

Actual Behavior

The console initially shows unwrappedAtom result: undefined, then later shows unwrappedAtom result: { data: 'Hello, World!' }.

Reproduction Link

https://codesandbox.io/p/sandbox/6lvjqt

[koutaro-masaki]

Sorry, I only searched Issues and didn't notice this Discussion earlier.

I understand this is an intended change, but the unwrap behavior still feels a bit surprising to me.