fix: should update dependents with the value of the unwrapped atom when the promise resolves

src/vanilla/store.ts

@@ -569,11 +569,17 @@ const buildStore = (...storeArgs: StoreArgs): Store => {
 
   const mountDependencies = (atom: AnyAtom, atomState: AtomState) => {
     if (atomState.m && !isPendingPromise(atomState.v)) {
-      for (const a of atomState.d.keys()) {
+      for (const [a, n] of atomState.d) {
         if (!atomState.m.d.has(a)) {
-          const aMounted = mountAtom(a, ensureAtomState(a))
+          const aState = ensureAtomState(a)
+          const aMounted = mountAtom(a, aState)
           aMounted.t.add(atom)
           atomState.m.d.add(a)
+          if (n !== aState.n) {
+            changedAtoms.set(a, aState)
+            aState.u?.()
+            invalidateDependents(aState)
+          }
         }
       }
       for (const a of atomState.m.d || []) {

tests/vanilla/utils/unwrap.test.ts

@@ -150,3 +150,17 @@ describe('unwrap', () => {
     expect(store.get(syncAtom)).toEqual('concrete')
   })
 })
+
+it('should update dependents with the value of the unwrapped atom when the promise resolves', async () => {
+  const store = createStore()
+  const asyncTarget = atom(() => Promise.resolve('value'))
+  const target = unwrap(asyncTarget)
+  const results: string[] = []
+  const derived = atom(async (get) => {
+    await Promise.resolve()
+    results.push('effect ' + get(target))
+  })
+  store.sub(derived, () => {})
+  await new Promise((r) => setTimeout(r))
+  expect(results).toEqual(['effect undefined', 'effect value'])
+})