fix(watch): flush:pre watchers should not fire if state change causes

owner component to unmount

fix #2291

packages/runtime-core/__tests__/scheduler.spec.ts

@@ -3,9 +3,8 @@ import {
   nextTick,
   queuePostFlushCb,
   invalidateJob,
-  queuePreFlushCb,
-  flushPreFlushCbs,
-  flushPostFlushCbs
+  flushPostFlushCbs,
+  flushPreFlushCbs
 } from '../src/scheduler'
 
 describe('scheduler', () => {
@@ -114,65 +113,7 @@ describe('scheduler', () => {
     })
   })
 
-  describe('queuePreFlushCb', () => {
-    it('basic usage', async () => {
-      const calls: string[] = []
-      const cb1 = () => {
-        calls.push('cb1')
-      }
-      const cb2 = () => {
-        calls.push('cb2')
-      }
-
-      queuePreFlushCb(cb1)
-      queuePreFlushCb(cb2)
-
-      expect(calls).toEqual([])
-      await nextTick()
-      expect(calls).toEqual(['cb1', 'cb2'])
-    })
-
-    it('should dedupe queued preFlushCb', async () => {
-      const calls: string[] = []
-      const cb1 = () => {
-        calls.push('cb1')
-      }
-      const cb2 = () => {
-        calls.push('cb2')
-      }
-      const cb3 = () => {
-        calls.push('cb3')
-      }
-
-      queuePreFlushCb(cb1)
-      queuePreFlushCb(cb2)
-      queuePreFlushCb(cb1)
-      queuePreFlushCb(cb2)
-      queuePreFlushCb(cb3)
-
-      expect(calls).toEqual([])
-      await nextTick()
-      expect(calls).toEqual(['cb1', 'cb2', 'cb3'])
-    })
-
-    it('chained queuePreFlushCb', async () => {
-      const calls: string[] = []
-      const cb1 = () => {
-        calls.push('cb1')
-        // cb2 will be executed after cb1 at the same tick
-        queuePreFlushCb(cb2)
-      }
-      const cb2 = () => {
-        calls.push('cb2')
-      }
-      queuePreFlushCb(cb1)
-
-      await nextTick()
-      expect(calls).toEqual(['cb1', 'cb2'])
-    })
-  })
-
-  describe('queueJob w/ queuePreFlushCb', () => {
+  describe('pre flush jobs', () => {
     it('queueJob inside preFlushCb', async () => {
       const calls: string[] = []
       const job1 = () => {
@@ -183,8 +124,9 @@ describe('scheduler', () => {
         calls.push('cb1')
         queueJob(job1)
       }
+      cb1.pre = true
 
-      queuePreFlushCb(cb1)
+      queueJob(cb1)
       await nextTick()
       expect(calls).toEqual(['cb1', 'job1'])
     })
@@ -194,17 +136,23 @@ describe('scheduler', () => {
       const job1 = () => {
         calls.push('job1')
       }
+      job1.id = 1
+
       const cb1 = () => {
         calls.push('cb1')
         queueJob(job1)
         // cb2 should execute before the job
-        queuePreFlushCb(cb2)
+        queueJob(cb2)
       }
+      cb1.pre = true
+
       const cb2 = () => {
         calls.push('cb2')
       }
+      cb2.pre = true
+      cb2.id = 1
 
-      queuePreFlushCb(cb1)
+      queueJob(cb1)
       await nextTick()
       expect(calls).toEqual(['cb1', 'cb2', 'job1'])
     })
@@ -216,9 +164,9 @@ describe('scheduler', () => {
         // when updating the props of a child component. This is handled
         // directly inside `updateComponentPreRender` to avoid non atomic
         // cb triggers (#1763)
-        queuePreFlushCb(cb1)
-        queuePreFlushCb(cb2)
-        flushPreFlushCbs(undefined, job1)
+        queueJob(cb1)
+        queueJob(cb2)
+        flushPreFlushCbs()
         calls.push('job1')
       }
       const cb1 = () => {
@@ -226,9 +174,11 @@ describe('scheduler', () => {
         // a cb triggers its parent job, which should be skipped
         queueJob(job1)
       }
+      cb1.pre = true
       const cb2 = () => {
         calls.push('cb2')
       }
+      cb2.pre = true
 
       queueJob(job1)
       await nextTick()
@@ -237,12 +187,14 @@ describe('scheduler', () => {
 
     // #3806
     it('queue preFlushCb inside postFlushCb', async () => {
-      const cb = jest.fn()
+      const spy = jest.fn()
+      const cb = () => spy()
+      cb.pre = true
       queuePostFlushCb(() => {
-        queuePreFlushCb(cb)
+        queueJob(cb)
       })
       await nextTick()
-      expect(cb).toHaveBeenCalled()
+      expect(spy).toHaveBeenCalled()
     })
   })