Revert "feat(runtime-core): add once option to watch (vuejs#9034)"

This reverts commit d573e50.

Author: johnsoncodehk

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

@@ -1205,42 +1205,4 @@ describe('api: watch', () => {
     expect(countWE).toBe(3)
     expect(countW).toBe(2)
   })
-
-  const options = [
-    { name: 'only trigger once watch' },
-    {
-      deep: true,
-      name: 'only trigger once watch with deep'
-    },
-    {
-      flush: 'sync',
-      name: 'only trigger once watch with flush: sync'
-    },
-    {
-      flush: 'pre',
-      name: 'only trigger once watch with flush: pre'
-    },
-    {
-      immediate: true,
-      name: 'only trigger once watch with immediate'
-    }
-  ] as const
-  test.each(options)('$name', async option => {
-    const count = ref(0)
-    const cb = vi.fn()
-
-    watch(count, cb, { once: true, ...option })
-
-    count.value++
-    await nextTick()
-
-    expect(count.value).toBe(1)
-    expect(cb).toHaveBeenCalledTimes(1)
-
-    count.value++
-    await nextTick()
-
-    expect(count.value).toBe(2)
-    expect(cb).toHaveBeenCalledTimes(1)
-  })
 })

packages/runtime-core/src/apiWatch.ts

@@ -74,7 +74,6 @@ export interface WatchOptionsBase extends DebuggerOptions {
 export interface WatchOptions<Immediate = boolean> extends WatchOptionsBase {
   immediate?: Immediate
   deep?: boolean
-  once?: boolean
 }
 
 export type WatchStopHandle = () => void
@@ -172,16 +171,8 @@ export function watch<T = any, Immediate extends Readonly<boolean> = false>(
 function doWatch(
   source: WatchSource | WatchSource[] | WatchEffect | object,
   cb: WatchCallback | null,
-  { immediate, deep, flush, once, onTrack, onTrigger }: WatchOptions = EMPTY_OBJ
+  { immediate, deep, flush, onTrack, onTrigger }: WatchOptions = EMPTY_OBJ
 ): WatchStopHandle {
-  if (cb && once) {
-    const _cb = cb
-    cb = (...args) => {
-      _cb(...args)
-      unwatch()
-    }
-  }
-
   if (__DEV__ && !cb) {
     if (immediate !== undefined) {
       warn(
@@ -195,12 +186,6 @@ function doWatch(
           `watch(source, callback, options?) signature.`
       )
     }
-    if (once !== undefined) {
-      warn(
-        `watch() "once" option is only respected when using the ` +
-          `watch(source, callback, options?) signature.`
-      )
-    }
   }
 
   const warnInvalidSource = (s: unknown) => {
@@ -380,13 +365,6 @@ function doWatch(
     onScheduled(schedulerJob as any)
   })
 
-  const unwatch = () => {
-    effect.stop()
-    if (instance && instance.scope) {
-      remove(instance.scope.effects!, effect)
-    }
-  }
-
   if (__DEV__) {
     effect.onTrack = onTrack
     effect.onTrigger = onTrigger
@@ -408,6 +386,13 @@ function doWatch(
     effect.run()
   }
 
+  const unwatch = () => {
+    effect.stop()
+    if (instance && instance.scope) {
+      remove(instance.scope.effects!, effect)
+    }
+  }
+
   if (__SSR__ && ssrCleanup) ssrCleanup.push(unwatch)
   return unwatch
 }