From 11d8e184b0e57d1660b09edc050fde79f891b8db Mon Sep 17 00:00:00 2001
From: eryue0220 <eryue0220@gmail.com>
Date: Thu, 19 Oct 2023 23:02:36 +0800
Subject: [PATCH 1/2] fix: store bug

---
 src/vanilla/store.ts         | 10 +++++++---
 tests/vanilla/store.test.tsx | 12 ++++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/vanilla/store.ts b/src/vanilla/store.ts
index d2f7bcc2a2..e936cc9b44 100644
--- a/src/vanilla/store.ts
+++ b/src/vanilla/store.ts
@@ -368,9 +368,13 @@ export const createStore = () => {
       // Otherwise, check if the dependencies have changed.
       // If all dependencies haven't changed, we can use the cache.
       if (
-        Array.from(atomState.d).every(
-          ([a, s]) => a === atom || readAtomState(a) === s
-        )
+        Array.from(atomState.d).every(([a, s]) => {
+          if (a === atom) {
+            return true
+          }
+          const aState = readAtomState(a)
+          return aState === s || (aState && !hasPromiseAtomValue(aState))
+        })
       ) {
         return atomState
       }
diff --git a/tests/vanilla/store.test.tsx b/tests/vanilla/store.test.tsx
index a95d35b12a..6093439d74 100644
--- a/tests/vanilla/store.test.tsx
+++ b/tests/vanilla/store.test.tsx
@@ -423,3 +423,15 @@ it('should update derived atoms during write (#2107)', async () => {
   store.set(countAtom, 2)
   expect(store.get(countAtom)).toBe(2)
 })
+
+it('should not recompute a derived atom value if unchanged (#2168)', async () => {
+  const store = createStore()
+  const countAtom = atom(1)
+  const derived1Atom = atom((get) => get(countAtom) * 0)
+  const derive2Fn = vi.fn((get: Getter) => get(derived1Atom))
+  const derived2Atom = atom(derive2Fn)
+  expect(store.get(derived2Atom)).toBe(0)
+  store.set(countAtom, (c) => c + 1)
+  expect(store.get(derived2Atom)).toBe(0)
+  expect(derive2Fn).toHaveBeenCalledTimes(1)
+})

From a868c65e2cebe642d40715e51079818390bb9b75 Mon Sep 17 00:00:00 2001
From: daishi <daishi@axlight.com>
Date: Sun, 22 Oct 2023 22:28:11 +0900
Subject: [PATCH 2/2] fix to pass the test

---
 src/vanilla/store.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/vanilla/store.ts b/src/vanilla/store.ts
index e936cc9b44..bde30f57d4 100644
--- a/src/vanilla/store.ts
+++ b/src/vanilla/store.ts
@@ -373,7 +373,11 @@ export const createStore = () => {
             return true
           }
           const aState = readAtomState(a)
-          return aState === s || (aState && !hasPromiseAtomValue(aState))
+          return (
+            aState === s ||
+            // We need to check values in case only dependencies are changed
+            (aState && isEqualAtomValue(aState, s))
+          )
         })
       ) {
         return atomState