refactor: move scheduler types back to core

packages/reactivity/__tests__/watch.spec.ts

@@ -1,15 +1,14 @@
 import {
   EffectScope,
   type Ref,
-  type SchedulerJob,
   WatchErrorCodes,
   type WatchScheduler,
   onWatcherCleanup,
   ref,
   watch,
 } from '../src'
 
-const queue: SchedulerJob[] = []
+const queue: (() => void)[] = []
 
 // a simple scheduler for testing purposes
 let isFlushPending = false
@@ -19,7 +18,7 @@ const nextTick = (fn?: () => any) =>
 
 const scheduler: WatchScheduler = (job, isFirstRun) => {
   if (isFirstRun) {
-    job(true)
+    job()
   } else {
     queue.push(job)
     flushJobs()

packages/reactivity/src/index.ts

@@ -89,4 +89,3 @@ export {
   type WatchOptions,
   type WatchScheduler,
 } from './watch'
-export { type SchedulerJob, SchedulerJobFlags } from './scheduler'

packages/reactivity/src/watch.ts

@@ -23,7 +23,6 @@ import {
 } from './effect'
 import { isReactive, isShallow } from './reactive'
 import { type Ref, isRef } from './ref'
-import { type SchedulerJob, SchedulerJobFlags } from './scheduler'
 
 // These errors were transferred from `packages/runtime-core/src/errorHandling.ts`
 // to @vue/reactivity to allow co-location with the moved base watch logic, hence
@@ -48,14 +47,15 @@ export interface WatchOptions<Immediate = boolean> extends DebuggerOptions {
   deep?: boolean | number
   once?: boolean
   scheduler?: WatchScheduler
+  augmentJob?: (job: (...args: any[]) => void) => void
   onError?: HandleError
   onWarn?: HandleWarn
 }
 
 // initial value for watchers to trigger on undefined initial values
 const INITIAL_WATCHER_VALUE = {}
 
-export type WatchScheduler = (job: SchedulerJob, isFirstRun: boolean) => void
+export type WatchScheduler = (job: () => void, isFirstRun: boolean) => void
 export type HandleError = (err: unknown, type: WatchErrorCodes) => void
 export type HandleWarn = (msg: string, ...args: any[]) => void
 
@@ -105,6 +105,7 @@ export function watch(
     deep,
     once,
     scheduler,
+    augmentJob,
     onWarn = __DEV__ ? warn : NOOP,
     onError = DEFAULT_HANDLE_ERROR,
     onTrack,
@@ -217,7 +218,8 @@ export function watch(
   let oldValue: any = isMultiSource
     ? new Array((source as []).length).fill(INITIAL_WATCHER_VALUE)
     : INITIAL_WATCHER_VALUE
-  const job: SchedulerJob = (immediateFirstRun?: boolean) => {
+
+  const job = (immediateFirstRun?: boolean) => {
     if (
       !(effect.flags & EffectFlags.ACTIVE) ||
       (!effect.dirty && !immediateFirstRun)
@@ -267,9 +269,9 @@ export function watch(
     }
   }
 
-  // important: mark the job as a watcher callback so that scheduler knows
-  // it is allowed to self-trigger (#1727)
-  if (cb) job.flags! |= SchedulerJobFlags.ALLOW_RECURSE
+  if (augmentJob) {
+    augmentJob(job)
+  }
 
   effect = new ReactiveEffect(getter)
   if (scheduler) {

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

@@ -1,6 +1,6 @@
-import { SchedulerJobFlags } from '@vue/reactivity'
 import {
   type SchedulerJob,
+  SchedulerJobFlags,
   flushPostFlushCbs,
   flushPreFlushCbs,
   nextTick,

packages/runtime-core/src/apiWatch.ts

@@ -4,12 +4,11 @@ import {
   type DebuggerOptions,
   type ReactiveMarker,
   type Ref,
-  SchedulerJobFlags,
   type WatchErrorCodes,
   watch as baseWatch,
   getCurrentScope,
 } from '@vue/reactivity'
-import { type SchedulerJob, queueJob } from './scheduler'
+import { type SchedulerJob, SchedulerJobFlags, queueJob } from './scheduler'
 import {
   EMPTY_OBJ,
   NOOP,
@@ -211,26 +210,38 @@ function doWatch(
     handleErrorWithInstance(err, instance, type)
 
   // scheduler
+  let isPre = false
   if (flush === 'post') {
     baseWatchOptions.scheduler = job => {
       queuePostRenderEffect(job, instance && instance.suspense)
     }
   } else if (flush !== 'sync') {
     // default: 'pre'
+    isPre = true
     baseWatchOptions.scheduler = (job, isFirstRun) => {
       if (isFirstRun) {
         job()
       } else {
-        job.flags! |= SchedulerJobFlags.PRE
-        if (instance) {
-          job.id = instance.uid
-          ;(job as SchedulerJob).i = instance
-        }
         queueJob(job)
       }
     }
   }
 
+  baseWatchOptions.augmentJob = (job: SchedulerJob) => {
+    // important: mark the job as a watcher callback so that scheduler knows
+    // it is allowed to self-trigger (#1727)
+    if (cb) {
+      job.flags! |= SchedulerJobFlags.ALLOW_RECURSE
+    }
+    if (isPre) {
+      job.flags! |= SchedulerJobFlags.PRE
+      if (instance) {
+        job.id = instance.uid
+        ;(job as SchedulerJob).i = instance
+      }
+    }
+  }
+
   const effect = baseWatch(source, cb, baseWatchOptions)
   const scope = getCurrentScope()
   const watchHandle: WatchHandle = () => {

packages/runtime-core/src/components/BaseTransition.ts

@@ -14,12 +14,13 @@ import {
 } from '../vnode'
 import { warn } from '../warning'
 import { isKeepAlive } from './KeepAlive'
-import { SchedulerJobFlags, toRaw } from '@vue/reactivity'
+import { toRaw } from '@vue/reactivity'
 import { ErrorCodes, callWithAsyncErrorHandling } from '../errorHandling'
 import { PatchFlags, ShapeFlags, isArray, isFunction } from '@vue/shared'
 import { onBeforeUnmount, onMounted } from '../apiLifecycle'
 import { isTeleport } from './Teleport'
 import type { RendererElement } from '../renderer'
+import { SchedulerJobFlags } from '../scheduler'
 
 type Hook<T = () => void> = T | T[]
 

packages/runtime-core/src/renderer.ts

@@ -41,6 +41,7 @@ import {
 } from '@vue/shared'
 import {
   type SchedulerJob,
+  SchedulerJobFlags,
   type SchedulerJobs,
   flushPostFlushCbs,
   flushPreFlushCbs,
@@ -50,7 +51,6 @@ import {
 import {
   EffectFlags,
   ReactiveEffect,
-  SchedulerJobFlags,
   pauseTracking,
   resetTracking,
 } from '@vue/reactivity'

packages/runtime-core/src/scheduler.ts

@@ -1,12 +1,36 @@
 import { ErrorCodes, callWithErrorHandling, handleError } from './errorHandling'
 import { type Awaited, NOOP, isArray } from '@vue/shared'
 import { type ComponentInternalInstance, getComponentName } from './component'
-import {
-  type SchedulerJob as BaseSchedulerJob,
-  SchedulerJobFlags,
-} from '@vue/reactivity'
 
-export interface SchedulerJob extends BaseSchedulerJob {
+export enum SchedulerJobFlags {
+  QUEUED = 1 << 0,
+  PRE = 1 << 1,
+  /**
+   * Indicates whether the effect is allowed to recursively trigger itself
+   * when managed by the scheduler.
+   *
+   * By default, a job cannot trigger itself because some built-in method calls,
+   * e.g. Array.prototype.push actually performs reads as well (#1740) which
+   * can lead to confusing infinite loops.
+   * The allowed cases are component update functions and watch callbacks.
+   * Component update functions may update child component props, which in turn
+   * trigger flush: "pre" watch callbacks that mutates state that the parent
+   * relies on (#1801). Watch callbacks doesn't track its dependencies so if it
+   * triggers itself again, it's likely intentional and it is the user's
+   * responsibility to perform recursive state mutation that eventually
+   * stabilizes (#1727).
+   */
+  ALLOW_RECURSE = 1 << 2,
+  DISPOSED = 1 << 3,
+}
+
+export interface SchedulerJob extends Function {
+  id?: number
+  /**
+   * flags can technically be undefined, but it can still be used in bitwise
+   * operations just like 0.
+   */
+  flags?: SchedulerJobFlags
   /**
    * Attached by renderer.ts when setting up a component's render effect
    * Used to obtain component information when reporting max recursive updates.