From 98864a7ef5c8080c407166c8221488a4eacbbc81 Mon Sep 17 00:00:00 2001
From: yangxiuxiu <79584569+yangxiuxiu1115@users.noreply.github.com>
Date: Thu, 5 Sep 2024 16:10:37 +0800
Subject: [PATCH] fix(reactivity): pass oldValue to computed getter (#11813)

close #11812
---
 packages/reactivity/__tests__/computed.spec.ts | 14 ++++++++++++++
 packages/reactivity/src/effect.ts              |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/packages/reactivity/__tests__/computed.spec.ts b/packages/reactivity/__tests__/computed.spec.ts
index 08b034f79f1..c3409eee77e 100644
--- a/packages/reactivity/__tests__/computed.spec.ts
+++ b/packages/reactivity/__tests__/computed.spec.ts
@@ -33,6 +33,20 @@ describe('reactivity/computed', () => {
     expect(cValue.value).toBe(1)
   })
 
+  it('pass oldValue to computed getter', () => {
+    const count = ref(0)
+    const oldValue = ref()
+    const curValue = computed(pre => {
+      oldValue.value = pre
+      return count.value
+    })
+    expect(curValue.value).toBe(0)
+    expect(oldValue.value).toBe(undefined)
+    count.value++
+    expect(curValue.value).toBe(1)
+    expect(oldValue.value).toBe(0)
+  })
+
   it('should compute lazily', () => {
     const value = reactive<{ foo?: number }>({})
     const getter = vi.fn(() => value.foo)
diff --git a/packages/reactivity/src/effect.ts b/packages/reactivity/src/effect.ts
index a22990f6729..88493e4e9a9 100644
--- a/packages/reactivity/src/effect.ts
+++ b/packages/reactivity/src/effect.ts
@@ -381,7 +381,7 @@ export function refreshComputed(computed: ComputedRefImpl): false | undefined {
 
   try {
     prepareDeps(computed)
-    const value = computed.fn()
+    const value = computed.fn(computed._value)
     if (dep.version === 0 || hasChanged(value, computed._value)) {
       computed._value = value
       dep.version++