fix(runtime-core/scheduler): handle nested flushPostFlushCbs calls

fix #1947
vuejs · Aug 24, 2020 · 36fa42a · 36fa42a
1 parent 499bc0b
commit 36fa42a
Show file tree

Hide file tree

Showing 2 changed files with 32 additions and 2 deletions.
diff --git a/packages/runtime-core/__tests__/scheduler.spec.ts b/packages/runtime-core/__tests__/scheduler.spec.ts
@@ -4,7 +4,8 @@ import {
  queuePostFlushCb,
  invalidateJob,
  queuePreFlushCb,
- flushPreFlushCbs
+ flushPreFlushCbs,
+ flushPostFlushCbs
 } from '../src/scheduler'
 
 describe('scheduler', () => {
@@ -505,4 +506,24 @@ describe('scheduler', () => {
  await nextTick()
  expect(count).toBe(1)
  })
+
+ // #1947 flushPostFlushCbs should handle nested calls
+ // e.g. app.mount inside app.mount
+ test('flushPostFlushCbs', async () => {
+ let count = 0
+
+ const queueAndFlush = (hook: Function) => {
+ queuePostFlushCb(hook)
+ flushPostFlushCbs()
+ }
+
+ queueAndFlush(() => {
+ queueAndFlush(() => {
+ count++
+ })
+ })
+
+ await nextTick()
+ expect(count).toBe(1)
+ })
 })
diff --git a/packages/runtime-core/src/scheduler.ts b/packages/runtime-core/src/scheduler.ts
@@ -151,8 +151,16 @@ export function flushPreFlushCbs(
 
 export function flushPostFlushCbs(seen?: CountMap) {
  if (pendingPostFlushCbs.length) {
- activePostFlushCbs = [...new Set(pendingPostFlushCbs)]
+ const deduped = [...new Set(pendingPostFlushCbs)]
  pendingPostFlushCbs.length = 0
+
+ // #1947 already has active queue, nested flushPostFlushCbs call
+ if (activePostFlushCbs) {
+ activePostFlushCbs.push(...deduped)
+ return
+ }
+
+ activePostFlushCbs = deduped
  if (__DEV__) {
  seen = seen || new Map()
  }
@@ -167,6 +175,7 @@ export function flushPostFlushCbs(seen?: CountMap) {
  if (__DEV__) {
  checkRecursiveUpdates(seen!, activePostFlushCbs[postFlushIndex])
  }
+ console.log(postFlushIndex)
  activePostFlushCbs[postFlushIndex]()
  }
  activePostFlushCbs = null