From: Evan You <yyx990803@gmail.com>
Date: Wed, 26 May 2021 18:21:49 +0000 (-0400)
Subject: fix(scheduler): handle preFlush cb queued inside postFlush cb
X-Git-Tag: v3.1.0-beta.5~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b57e995edd29eff685aeaf40712e0e029073d1cb;p=thirdparty%2Fvuejs%2Fcore.git

fix(scheduler): handle preFlush cb queued inside postFlush cb

fix #3806
---

diff --git a/packages/runtime-core/__tests__/scheduler.spec.ts b/packages/runtime-core/__tests__/scheduler.spec.ts
index 3d95be5edb..953f928158 100644
--- a/packages/runtime-core/__tests__/scheduler.spec.ts
+++ b/packages/runtime-core/__tests__/scheduler.spec.ts
@@ -230,6 +230,16 @@ describe('scheduler', () => {
       await nextTick()
       expect(calls).toEqual(['cb1', 'cb2', 'job1'])
     })
+
+    // #3806
+    it('queue preFlushCb inside postFlushCb', async () => {
+      const cb = jest.fn()
+      queuePostFlushCb(() => {
+        queuePreFlushCb(cb)
+      })
+      await nextTick()
+      expect(cb).toHaveBeenCalled()
+    })
   })
 
   describe('queuePostFlushCb', () => {
diff --git a/packages/runtime-core/src/scheduler.ts b/packages/runtime-core/src/scheduler.ts
index 8ab5a23108..5729afbbec 100644
--- a/packages/runtime-core/src/scheduler.ts
+++ b/packages/runtime-core/src/scheduler.ts
@@ -260,7 +260,11 @@ function flushJobs(seen?: CountMap) {
     currentFlushPromise = null
     // some postFlushCb queued jobs!
     // keep flushing until it drains.
-    if (queue.length || pendingPostFlushCbs.length) {
+    if (
+      queue.length ||
+      pendingPreFlushCbs.length ||
+      pendingPostFlushCbs.length
+    ) {
       flushJobs(seen)
     }
   }