From ff5acb12cfa64f975f216a55aafa976b07052665 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 4 Jul 2022 10:37:05 +0800
Subject: [PATCH] fix: fix NaN comparison on state change

fix #12595
---
 src/shared/util.ts                            |  2 +-
 .../features/v3/reactivity/reactive.spec.ts   | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/shared/util.ts b/src/shared/util.ts
index a171a743c14..0b9cf7f06ec 100644
--- a/src/shared/util.ts
+++ b/src/shared/util.ts
@@ -361,6 +361,6 @@ export function hasChanged(x: unknown, y: unknown): boolean {
   if (x === y) {
     return x === 0 && 1 / x !== 1 / (y as number)
   } else {
-    return x === x && y === y
+    return x === x || y === y
   }
 }
diff --git a/test/unit/features/v3/reactivity/reactive.spec.ts b/test/unit/features/v3/reactivity/reactive.spec.ts
index e5e381d71df..f636d44d4a1 100644
--- a/test/unit/features/v3/reactivity/reactive.spec.ts
+++ b/test/unit/features/v3/reactivity/reactive.spec.ts
@@ -278,4 +278,29 @@ describe('reactivity/reactive', () => {
     const observed = reactive(original)
     expect(isReactive(observed)).toBe(false)
   })
+
+  // #12595
+  test(`should not trigger if value didn't change`, () => {
+    const state = reactive({
+      foo: 1
+    })
+    const spy = vi.fn()
+    effect(() => {
+      state.foo
+      spy()
+    })
+    expect(spy).toHaveBeenCalledTimes(1)
+
+    state.foo = 1
+    expect(spy).toHaveBeenCalledTimes(1)
+
+    state.foo = NaN
+    expect(spy).toHaveBeenCalledTimes(2)
+
+    state.foo = NaN
+    expect(spy).toHaveBeenCalledTimes(2)
+
+    state.foo = 2
+    expect(spy).toHaveBeenCalledTimes(3)
+  })
 })