From f0057b101e6451d5095cdb7fd6308fd31ac0450c Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Mon, 15 Aug 2022 19:06:38 +0800
Subject: [PATCH] fix(watch): avoid pre watcher firing on unmount

fix #12703
---
 src/v3/apiWatch.ts                     | 5 +----
 test/unit/features/v3/apiWatch.spec.ts | 4 ++--
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/v3/apiWatch.ts b/src/v3/apiWatch.ts
index 7fe5eeb9d..141a58eb6 100644
--- a/src/v3/apiWatch.ts
+++ b/src/v3/apiWatch.ts
@@ -274,10 +274,7 @@ function doWatch(
   let oldValue = isMultiSource ? [] : INITIAL_WATCHER_VALUE
   // overwrite default run
   watcher.run = () => {
-    if (
-      !watcher.active &&
-      !(flush === 'pre' && instance && instance._isBeingDestroyed)
-    ) {
+    if (!watcher.active) {
       return
     }
     if (cb) {
diff --git a/test/unit/features/v3/apiWatch.spec.ts b/test/unit/features/v3/apiWatch.spec.ts
index 0206e8df3..c92bc150a 100644
--- a/test/unit/features/v3/apiWatch.spec.ts
+++ b/test/unit/features/v3/apiWatch.spec.ts
@@ -542,7 +542,7 @@ describe('api: watch', () => {
     expect(cb).not.toHaveBeenCalled()
   })
 
-  it('should fire on component unmount w/ flush: pre', async () => {
+  it('should not fire on component unmount w/ flush: pre', async () => {
     const toggle = ref(true)
     const cb = vi.fn()
     const Comp = {
@@ -560,7 +560,7 @@ describe('api: watch', () => {
     expect(cb).not.toHaveBeenCalled()
     toggle.value = false
     await nextTick()
-    expect(cb).toHaveBeenCalledTimes(1)
+    expect(cb).not.toHaveBeenCalled()
   })
 
   // vuejs/core#1763