From 07e02dcd84d8f502c6cb14736325c385b89dedb5 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 11:38:54 +0800
Subject: [PATCH 01/13] fix(transition): optimize prop handling in
 VaporTransition using Proxy

---
 .../src/components/Transition.ts              | 30 +++++++------------
 1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/packages/runtime-vapor/src/components/Transition.ts b/packages/runtime-vapor/src/components/Transition.ts
index 00871ff2bf1..eefd9356c2a 100644
--- a/packages/runtime-vapor/src/components/Transition.ts
+++ b/packages/runtime-vapor/src/components/Transition.ts
@@ -80,29 +80,19 @@ export const VaporTransition: FunctionalVaporComponent<TransitionProps> =
     checkTransitionMode(mode)
 
     let resolvedProps: BaseTransitionProps<Element>
-    let isMounted = false
-    renderEffect(() => {
-      resolvedProps = resolveTransitionProps(props)
-      if (isMounted) {
-        // only update props for Fragment transition, for later reusing
-        if (isFragment(children)) {
-          children.$transition!.props = resolvedProps
-        } else {
-          const child = findTransitionBlock(children)
-          if (child) {
-            // replace existing transition hooks
-            child.$transition!.props = resolvedProps
-            applyTransitionHooks(child, child.$transition!, true)
-          }
-        }
-      } else {
-        isMounted = true
-      }
-    })
+    renderEffect(() => (resolvedProps = resolveTransitionProps(props)))
 
     const hooks = applyTransitionHooks(children, {
       state: useTransitionState(),
-      props: resolvedProps!,
+      // use proxy to keep props reference stable
+      props: new Proxy(
+        {},
+        {
+          get(_, key) {
+            return resolvedProps[key as keyof BaseTransitionProps<Element>]
+          },
+        },
+      ),
       instance: instance,
     } as VaporTransitionHooks)
 

From b6d633db459c5c3666a799fb571411c08de7d850 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 11:43:59 +0800
Subject: [PATCH 02/13] fix(runtime-vapor): optimize prop handling in
 VaporTransitionGroup using Proxy

---
 .../src/components/TransitionGroup.ts          | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/packages/runtime-vapor/src/components/TransitionGroup.ts b/packages/runtime-vapor/src/components/TransitionGroup.ts
index 76d5acd1c1a..7055b612333 100644
--- a/packages/runtime-vapor/src/components/TransitionGroup.ts
+++ b/packages/runtime-vapor/src/components/TransitionGroup.ts
@@ -21,6 +21,7 @@ import {
   type VaporTransitionHooks,
   insert,
 } from '../block'
+import { renderEffect } from '../renderEffect'
 import {
   resolveTransitionHooks,
   setTransitionHooks,
@@ -55,7 +56,18 @@ export const VaporTransitionGroup: ObjectVaporComponent = decorate({
   setup(props: TransitionGroupProps, { slots }) {
     const instance = currentInstance as VaporComponentInstance
     const state = useTransitionState()
-    const cssTransitionProps = resolveTransitionProps(props)
+
+    // use proxy to keep props reference stable
+    let cssTransitionProps = resolveTransitionProps(props)
+    const propsProxy = new Proxy({} as typeof cssTransitionProps, {
+      get(_, key) {
+        return cssTransitionProps[key as keyof typeof cssTransitionProps]
+      },
+    })
+
+    renderEffect(() => {
+      cssTransitionProps = resolveTransitionProps(props)
+    })
 
     let prevChildren: TransitionBlock[]
     let children: TransitionBlock[]
@@ -121,7 +133,7 @@ export const VaporTransitionGroup: ObjectVaporComponent = decorate({
 
     // store props and state on fragment for reusing during insert new items
     setTransitionHooksOnFragment(slottedBlock, {
-      props: cssTransitionProps,
+      props: propsProxy,
       state,
       instance,
     } as VaporTransitionHooks)
@@ -133,7 +145,7 @@ export const VaporTransitionGroup: ObjectVaporComponent = decorate({
         if (child.$key != null) {
           const hooks = resolveTransitionHooks(
             child,
-            cssTransitionProps,
+            propsProxy,
             state,
             instance!,
           )

From 11202987acc386fc0c1f4e1d3c01b9f3bdedc2d9 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 11:48:34 +0800
Subject: [PATCH 03/13] fix(runtime-vapor): remove unused isResolved parameter
 from applyTransitionHooks

---
 packages/runtime-vapor/src/components/Transition.ts | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/packages/runtime-vapor/src/components/Transition.ts b/packages/runtime-vapor/src/components/Transition.ts
index eefd9356c2a..51f59e477d2 100644
--- a/packages/runtime-vapor/src/components/Transition.ts
+++ b/packages/runtime-vapor/src/components/Transition.ts
@@ -175,7 +175,6 @@ export function resolveTransitionHooks(
 export function applyTransitionHooks(
   block: Block,
   hooks: VaporTransitionHooks,
-  isResolved: boolean = false,
 ): VaporTransitionHooks {
   // filter out comment nodes
   if (isArray(block)) {
@@ -188,9 +187,7 @@ export function applyTransitionHooks(
   }
 
   const isFrag = isFragment(block)
-  const child = isResolved
-    ? (block as TransitionBlock)
-    : findTransitionBlock(block, isFrag)
+  const child = findTransitionBlock(block, isFrag)
   if (!child) {
     // set transition hooks on fragment for reusing during it's updating
     if (isFrag) setTransitionHooksOnFragment(block, hooks)

From 17372a93ba4305b42ff49c03f8050fae0f392e9d Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 14:01:24 +0800
Subject: [PATCH 04/13] fix(runtime-vapor): refactor transition hooks
 application to use callback pattern

---
 .../src/components/Transition.ts              | 45 +++++++++----------
 1 file changed, 20 insertions(+), 25 deletions(-)

diff --git a/packages/runtime-vapor/src/components/Transition.ts b/packages/runtime-vapor/src/components/Transition.ts
index 51f59e477d2..73593d47d76 100644
--- a/packages/runtime-vapor/src/components/Transition.ts
+++ b/packages/runtime-vapor/src/components/Transition.ts
@@ -27,7 +27,7 @@ import {
 } from '../component'
 import { isArray } from '@vue/shared'
 import { renderEffect } from '../renderEffect'
-import { isFragment } from '../fragment'
+import { type VaporFragment, isFragment } from '../fragment'
 import {
   currentHydrationNode,
   isHydrating,
@@ -85,14 +85,11 @@ export const VaporTransition: FunctionalVaporComponent<TransitionProps> =
     const hooks = applyTransitionHooks(children, {
       state: useTransitionState(),
       // use proxy to keep props reference stable
-      props: new Proxy(
-        {},
-        {
-          get(_, key) {
-            return resolvedProps[key as keyof BaseTransitionProps<Element>]
-          },
+      props: new Proxy({} as BaseTransitionProps<Element>, {
+        get(_, key) {
+          return resolvedProps[key as keyof BaseTransitionProps<Element>]
         },
-      ),
+      }),
       instance: instance,
     } as VaporTransitionHooks)
 
@@ -186,11 +183,15 @@ export function applyTransitionHooks(
     }
   }
 
-  const isFrag = isFragment(block)
-  const child = findTransitionBlock(block, isFrag)
+  const fragments: VaporFragment[] = []
+  const child = findTransitionBlock(block, frag => fragments.push(frag))
   if (!child) {
-    // set transition hooks on fragment for reusing during it's updating
-    if (isFrag) setTransitionHooksOnFragment(block, hooks)
+    // set transition hooks on fragments for later use
+    fragments.forEach(f => (f.$transition = hooks))
+    // warn if no child and no fragments
+    if (__DEV__ && fragments.length === 0) {
+      warn('Transition component has no valid child element')
+    }
     return hooks
   }
 
@@ -204,7 +205,7 @@ export function applyTransitionHooks(
   )
   resolvedHooks.delayedLeave = delayedLeave
   child.$transition = resolvedHooks
-  if (isFrag) setTransitionHooksOnFragment(block, resolvedHooks)
+  fragments.forEach(f => (f.$transition = resolvedHooks))
 
   return resolvedHooks
 }
@@ -260,7 +261,7 @@ export function applyTransitionLeaveHooks(
 
 export function findTransitionBlock(
   block: Block,
-  inFragment: boolean = false,
+  onFragment?: (frag: VaporFragment) => void,
 ): TransitionBlock | undefined {
   let child: TransitionBlock | undefined
   if (block instanceof Node) {
@@ -273,7 +274,7 @@ export function findTransitionBlock(
     } else {
       // stop searching if encountering nested Transition component
       if (getComponentName(block.type) === displayName) return undefined
-      child = findTransitionBlock(block.block, inFragment)
+      child = findTransitionBlock(block.block, onFragment)
       // use component id as key
       if (child && child.$key === undefined) child.$key = block.uid
     }
@@ -281,9 +282,7 @@ export function findTransitionBlock(
     let hasFound = false
     for (const c of block) {
       if (c instanceof Comment) continue
-      // check if the child is a fragment to suppress warnings
-      if (isFragment(c)) inFragment = true
-      const item = findTransitionBlock(c, inFragment)
+      const item = findTransitionBlock(c, onFragment)
       if (__DEV__ && hasFound) {
         // warn more than one non-comment child
         warn(
@@ -297,19 +296,15 @@ export function findTransitionBlock(
       if (!__DEV__) break
     }
   } else if (isFragment(block)) {
-    // mark as in fragment to suppress warnings
-    inFragment = true
     if (block.insert) {
       child = block
     } else {
-      child = findTransitionBlock(block.nodes, true)
+      // collect fragments for setting transition hooks
+      if (onFragment) onFragment(block)
+      child = findTransitionBlock(block.nodes, onFragment)
     }
   }
 
-  if (__DEV__ && !child && !inFragment) {
-    warn('Transition component has no valid child element')
-  }
-
   return child
 }
 

From 1f5b70c39eae5de81c69cda9286ac79115489772 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 14:04:30 +0800
Subject: [PATCH 05/13] fix(runtime-vapor): add move function for block
 repositioning with transition support

---
 packages/runtime-vapor/src/block.ts           | 24 +++++++++++++++++++
 .../runtime-vapor/src/components/KeepAlive.ts |  4 ++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/packages/runtime-vapor/src/block.ts b/packages/runtime-vapor/src/block.ts
index 323ef7beefc..713f1b89519 100644
--- a/packages/runtime-vapor/src/block.ts
+++ b/packages/runtime-vapor/src/block.ts
@@ -158,6 +158,30 @@ export function remove(block: Block, parent?: ParentNode): void {
   }
 }
 
+export function move(block: Block, parent: ParentNode): void {
+  if (block instanceof Node) {
+    if ((block as TransitionBlock).$transition && block instanceof Element) {
+      performTransitionLeave(
+        block,
+        (block as TransitionBlock).$transition as TransitionHooks,
+        () => insert(block, parent),
+      )
+    } else {
+      insert(block, parent)
+    }
+  } else if (isVaporComponent(block)) {
+    move(block.block, parent)
+  } else if (isArray(block)) {
+    for (let i = 0; i < block.length; i++) {
+      move(block[i], parent)
+    }
+  } else {
+    // fragment
+    move(block.nodes, parent)
+    if (block.anchor) move(block.anchor, parent)
+  }
+}
+
 /**
  * dev / test only
  */
diff --git a/packages/runtime-vapor/src/components/KeepAlive.ts b/packages/runtime-vapor/src/components/KeepAlive.ts
index 2c267b001ed..5c8a915feae 100644
--- a/packages/runtime-vapor/src/components/KeepAlive.ts
+++ b/packages/runtime-vapor/src/components/KeepAlive.ts
@@ -18,7 +18,7 @@ import {
   warn,
   watch,
 } from '@vue/runtime-dom'
-import { type Block, insert, remove } from '../block'
+import { type Block, insert, move, remove } from '../block'
 import {
   type ObjectVaporComponent,
   type VaporComponent,
@@ -358,7 +358,7 @@ export function deactivate(
   instance: VaporComponentInstance,
   container: ParentNode,
 ): void {
-  insert(instance.block, container)
+  move(instance.block, container)
 
   queuePostFlushCb(() => {
     if (instance.da) invokeArrayFns(instance.da)

From f7c9c6e81ffd376f0c18f867d4e6d21145f7cea6 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 15:09:45 +0800
Subject: [PATCH 06/13] fix(runtime-vapor): refactor move function into insert
 with MoveType parameter

---
 packages/runtime-vapor/__tests__/hmr.spec.ts  |  8 +++--
 packages/runtime-vapor/src/block.ts           | 33 +++++--------------
 .../runtime-vapor/src/components/KeepAlive.ts |  5 +--
 3 files changed, 17 insertions(+), 29 deletions(-)

diff --git a/packages/runtime-vapor/__tests__/hmr.spec.ts b/packages/runtime-vapor/__tests__/hmr.spec.ts
index 3618ee10644..88be0bbabdc 100644
--- a/packages/runtime-vapor/__tests__/hmr.spec.ts
+++ b/packages/runtime-vapor/__tests__/hmr.spec.ts
@@ -276,11 +276,14 @@ describe('hot module replacement', () => {
       components: { Child },
       setup() {
         const toggle = ref(true)
-        return { toggle }
+        function onLeave(_: any, done: Function) {
+          setTimeout(done, 0)
+        }
+        return { toggle, onLeave }
       },
       render: compileToFunction(
         `<button @click="toggle = !toggle" />
-        <Transition>
+        <Transition @leave="onLeave">
           <KeepAlive><Child v-if="toggle" /></KeepAlive>
         </Transition>`,
       ),
@@ -303,6 +306,7 @@ describe('hot module replacement', () => {
       render: compileToFunction(`<div>{{ count }}</div>`),
     })
     await nextTick()
+    await new Promise(r => setTimeout(r, 0))
     expect(root.innerHTML).toBe(`<button></button><div>1</div><!--if-->`)
     expect(unmountSpy).toHaveBeenCalledTimes(1)
     expect(mountSpy).toHaveBeenCalledTimes(1)
diff --git a/packages/runtime-vapor/src/block.ts b/packages/runtime-vapor/src/block.ts
index 713f1b89519..20bc01e94b8 100644
--- a/packages/runtime-vapor/src/block.ts
+++ b/packages/runtime-vapor/src/block.ts
@@ -8,6 +8,7 @@ import {
 import { _child } from './dom/node'
 import { isComment, isHydrating } from './dom/hydration'
 import {
+  MoveType,
   type TransitionHooks,
   type TransitionProps,
   type TransitionState,
@@ -77,6 +78,7 @@ export function insert(
   block: Block,
   parent: ParentNode & { $fc?: Node | null },
   anchor: Node | null | 0 = null, // 0 means prepend
+  moveType: MoveType = MoveType.ENTER,
   parentSuspense?: any, // TODO Suspense
 ): void {
   anchor = anchor === 0 ? parent.$fc || _child(parent) : anchor
@@ -88,7 +90,12 @@ export function insert(
         (block as TransitionBlock).$transition &&
         !(block as TransitionBlock).$transition!.disabled
       ) {
-        performTransitionEnter(
+        const action =
+          moveType === MoveType.LEAVE
+            ? performTransitionLeave
+            : performTransitionEnter
+
+        action(
           block,
           (block as TransitionBlock).$transition as TransitionHooks,
           () => parent.insertBefore(block, anchor as Node),
@@ -158,30 +165,6 @@ export function remove(block: Block, parent?: ParentNode): void {
   }
 }
 
-export function move(block: Block, parent: ParentNode): void {
-  if (block instanceof Node) {
-    if ((block as TransitionBlock).$transition && block instanceof Element) {
-      performTransitionLeave(
-        block,
-        (block as TransitionBlock).$transition as TransitionHooks,
-        () => insert(block, parent),
-      )
-    } else {
-      insert(block, parent)
-    }
-  } else if (isVaporComponent(block)) {
-    move(block.block, parent)
-  } else if (isArray(block)) {
-    for (let i = 0; i < block.length; i++) {
-      move(block[i], parent)
-    }
-  } else {
-    // fragment
-    move(block.nodes, parent)
-    if (block.anchor) move(block.anchor, parent)
-  }
-}
-
 /**
  * dev / test only
  */
diff --git a/packages/runtime-vapor/src/components/KeepAlive.ts b/packages/runtime-vapor/src/components/KeepAlive.ts
index 5c8a915feae..616188b6f20 100644
--- a/packages/runtime-vapor/src/components/KeepAlive.ts
+++ b/packages/runtime-vapor/src/components/KeepAlive.ts
@@ -3,6 +3,7 @@ import {
   type GenericComponent,
   type GenericComponentInstance,
   type KeepAliveProps,
+  MoveType,
   type VNode,
   currentInstance,
   devtoolsComponentAdded,
@@ -18,7 +19,7 @@ import {
   warn,
   watch,
 } from '@vue/runtime-dom'
-import { type Block, insert, move, remove } from '../block'
+import { type Block, insert, remove } from '../block'
 import {
   type ObjectVaporComponent,
   type VaporComponent,
@@ -358,7 +359,7 @@ export function deactivate(
   instance: VaporComponentInstance,
   container: ParentNode,
 ): void {
-  move(instance.block, container)
+  insert(instance.block, container, null, MoveType.LEAVE)
 
   queuePostFlushCb(() => {
     if (instance.da) invokeArrayFns(instance.da)

From e2ca9d1a7d3db093538602dd73ccff276f998b57 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 15:23:46 +0800
Subject: [PATCH 07/13] refactor(runtime-core): move MoveType export to public
 API

---
 packages/runtime-core/src/index.ts | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/packages/runtime-core/src/index.ts b/packages/runtime-core/src/index.ts
index 9e589ef9156..068184e8265 100644
--- a/packages/runtime-core/src/index.ts
+++ b/packages/runtime-core/src/index.ts
@@ -133,6 +133,7 @@ export {
 export { withDirectives } from './directives'
 // SSR context
 export { useSSRContext, ssrContextKey } from './helpers/useSsrContext'
+export { MoveType } from './renderer'
 
 // Custom Renderer API ---------------------------------------------------------
 
@@ -519,11 +520,7 @@ export { type VaporInteropInterface } from './apiCreateApp'
 /**
  * @internal
  */
-export {
-  type RendererInternals,
-  MoveType,
-  getInheritedScopeIds,
-} from './renderer'
+export { type RendererInternals, getInheritedScopeIds } from './renderer'
 /**
  * @internal
  */

From 84be6558a0ff3f583301e7213d0dee3c7651a959 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 16:28:15 +0800
Subject: [PATCH 08/13] test(vapor-e2e): add transition test for keep-alive
 include update

---
 .../__tests__/transition.spec.ts              | 36 +++++++++++++
 .../vapor-e2e-test/transition/App.vue         | 50 +++++++++++++++++++
 2 files changed, 86 insertions(+)

diff --git a/packages-private/vapor-e2e-test/__tests__/transition.spec.ts b/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
index 1dce93782e1..27fe3ce6281 100644
--- a/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
+++ b/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
@@ -922,6 +922,42 @@ describe('vapor transition', () => {
       })
       expect(calls).toStrictEqual(['TrueBranch'])
     })
+
+    test(
+      'switch child then update include (out-in mode)',
+      async () => {
+        const containerSelector = '.keep-alive-update-include > div'
+        const btnSwitchToB = '.keep-alive-update-include > #switchToB'
+        const btnSwitchToA = '.keep-alive-update-include > #switchToA'
+        const btnSwitchToC = '.keep-alive-update-include > #switchToC'
+
+        await transitionFinish()
+        expect(await html(containerSelector)).toBe('<div>CompA</div>')
+
+        await click(btnSwitchToB)
+        await nextTick()
+        await click(btnSwitchToC)
+        await transitionFinish(duration * 3)
+        expect(await html(containerSelector)).toBe('<div class="">CompC</div>')
+
+        await click(btnSwitchToA)
+        await transitionFinish(duration * 3)
+        expect(await html(containerSelector)).toBe('<div class="">CompA</div>')
+
+        let calls = await page().evaluate(() => {
+          return (window as any).getCalls('unmount')
+        })
+        expect(calls).toStrictEqual(['CompC unmounted'])
+
+        // Unlike vdom, CompA does not update because there are no state changes
+        // expect CompA only update once
+        // calls = await page().evaluate(() => {
+        //   return (window as any).getCalls('updated')
+        // })
+        // expect(calls).toStrictEqual(['CompA updated'])
+      },
+      E2E_TIMEOUT,
+    )
   })
 
   describe.todo('transition with Suspense', () => {})
diff --git a/packages-private/vapor-e2e-test/transition/App.vue b/packages-private/vapor-e2e-test/transition/App.vue
index e7227ded01e..7b802f768bc 100644
--- a/packages-private/vapor-e2e-test/transition/App.vue
+++ b/packages-private/vapor-e2e-test/transition/App.vue
@@ -9,6 +9,7 @@ import {
   template,
   defineVaporAsyncComponent,
   onUnmounted,
+  onUpdated,
 } from 'vue'
 const show = ref(true)
 const toggle = ref(true)
@@ -31,6 +32,7 @@ let calls = {
   showAppear: [],
   notEnter: [],
 
+  updated: [],
   unmount: [],
 }
 window.getCalls = key => calls[key]
@@ -117,6 +119,42 @@ const click = () => {
     includeRef.value = []
   }
 }
+
+const CompA = defineVaporComponent({
+  name: 'CompA',
+  setup() {
+    onUpdated(() => {
+      calls.updated.push('CompA updated')
+    })
+    return template('<div>CompA</div>')()
+  },
+})
+
+const CompB = defineVaporComponent({
+  name: 'CompB',
+  setup() {
+    return template('<div>CompB</div>')()
+  },
+})
+
+const CompC = defineVaporComponent({
+  name: 'CompC',
+  setup() {
+    onUnmounted(() => {
+      calls.unmount.push('CompC unmounted')
+    })
+    return template('<div>CompC</div>')()
+  },
+})
+
+const includeToChange = ref(['CompA', 'CompB', 'CompC'])
+const currentView = shallowRef(CompA)
+const switchToB = () => (currentView.value = CompB)
+const switchToC = () => (currentView.value = CompC)
+const switchToA = () => {
+  currentView.value = CompA
+  includeToChange.value = ['CompA']
+}
 </script>
 
 <template>
@@ -545,6 +583,18 @@ const click = () => {
       </div>
       <button @click="click">button</button>
     </div>
+    <div class="keep-alive-update-include">
+      <div>
+        <transition mode="out-in">
+          <KeepAlive :include="includeToChange">
+            <component :is="currentView" />
+          </KeepAlive>
+        </transition>
+      </div>
+      <button id="switchToB" @click="switchToB">switchToB</button>
+      <button id="switchToC" @click="switchToC">switchToC</button>
+      <button id="switchToA" @click="switchToA">switchToA</button>
+    </div>
     <!-- with keep-alive end -->
 
     <!-- vdom interop -->

From f04a0247bd0b45961807e9810752f22f3f74a7f1 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 22:15:12 +0800
Subject: [PATCH 09/13] fix(Transition): prevent unmounted block from being
 inserted after transition leave

---
 packages/runtime-vapor/src/block.ts                | 11 ++++++++++-
 packages/runtime-vapor/src/components/KeepAlive.ts |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/packages/runtime-vapor/src/block.ts b/packages/runtime-vapor/src/block.ts
index 20bc01e94b8..090ba1b4d84 100644
--- a/packages/runtime-vapor/src/block.ts
+++ b/packages/runtime-vapor/src/block.ts
@@ -79,6 +79,7 @@ export function insert(
   parent: ParentNode & { $fc?: Node | null },
   anchor: Node | null | 0 = null, // 0 means prepend
   moveType: MoveType = MoveType.ENTER,
+  parentComponent?: VaporComponentInstance,
   parentSuspense?: any, // TODO Suspense
 ): void {
   anchor = anchor === 0 ? parent.$fc || _child(parent) : anchor
@@ -98,7 +99,15 @@ export function insert(
         action(
           block,
           (block as TransitionBlock).$transition as TransitionHooks,
-          () => parent.insertBefore(block, anchor as Node),
+          () => {
+            // if the component is unmounted after leave finish, remove the block
+            // to avoid retaining a detached node.
+            if (moveType === MoveType.LEAVE && parentComponent!.isUnmounted) {
+              block.remove()
+            } else {
+              parent.insertBefore(block, anchor as Node)
+            }
+          },
           parentSuspense,
         )
       } else {
diff --git a/packages/runtime-vapor/src/components/KeepAlive.ts b/packages/runtime-vapor/src/components/KeepAlive.ts
index 616188b6f20..04c2904b634 100644
--- a/packages/runtime-vapor/src/components/KeepAlive.ts
+++ b/packages/runtime-vapor/src/components/KeepAlive.ts
@@ -359,7 +359,7 @@ export function deactivate(
   instance: VaporComponentInstance,
   container: ParentNode,
 ): void {
-  insert(instance.block, container, null, MoveType.LEAVE)
+  insert(instance.block, container, null, MoveType.LEAVE, instance)
 
   queuePostFlushCb(() => {
     if (instance.da) invokeArrayFns(instance.da)

From 8633e309231970d1f1afef13d2ac1a1a892311ca Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 22:16:37 +0800
Subject: [PATCH 10/13] fix(runtime-vapor): fix scope preservation logic in
 onBeforeTeardown hooks

---
 packages/runtime-vapor/src/fragment.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/runtime-vapor/src/fragment.ts b/packages/runtime-vapor/src/fragment.ts
index 58cf1707162..6d73ceb088a 100644
--- a/packages/runtime-vapor/src/fragment.ts
+++ b/packages/runtime-vapor/src/fragment.ts
@@ -118,6 +118,7 @@ export class DynamicFragment extends VaporFragment {
       if (isHydrating) this.hydrate(true)
       return
     }
+    const prevKey = this.current
     this.current = key
 
     const instance = currentInstance
@@ -130,9 +131,11 @@ export class DynamicFragment extends VaporFragment {
       // if any of the hooks returns true the scope will be preserved
       // for kept-alive component
       if (this.onBeforeTeardown) {
-        preserveScope = this.onBeforeTeardown.some(hook =>
-          hook(this.current, this.nodes, this.scope!),
-        )
+        for (const teardown of this.onBeforeTeardown) {
+          if (teardown(prevKey, this.nodes, this.scope!)) {
+            preserveScope = true
+          }
+        }
       }
       if (!preserveScope) {
         this.scope.stop()

From c64c19b8cfacb4fa0e8f27affa2c54efd83f298b Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 22:18:57 +0800
Subject: [PATCH 11/13] fix(KeepAlive): preserve fragment's scope only if it
 include a component that should be cached

---
 packages/runtime-vapor/src/components/KeepAlive.ts | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/packages/runtime-vapor/src/components/KeepAlive.ts b/packages/runtime-vapor/src/components/KeepAlive.ts
index 04c2904b634..3eaefcba3c4 100644
--- a/packages/runtime-vapor/src/components/KeepAlive.ts
+++ b/packages/runtime-vapor/src/components/KeepAlive.ts
@@ -127,7 +127,7 @@ export const VaporKeepAliveImpl: ObjectVaporComponent = defineVaporComponent({
 
     const processFragment = (frag: DynamicFragment) => {
       const [innerBlock, interop] = getInnerBlock(frag.nodes)
-      if (!innerBlock || !shouldCache(innerBlock!, props, interop)) return
+      if (!innerBlock || !shouldCache(innerBlock!, props, interop)) return false
 
       if (interop) {
         if (cache.has(innerBlock.vnode!.type)) {
@@ -140,6 +140,7 @@ export const VaporKeepAliveImpl: ObjectVaporComponent = defineVaporComponent({
         }
         innerBlock!.shapeFlag! |= ShapeFlags.COMPONENT_SHOULD_KEEP_ALIVE
       }
+      return true
     }
 
     const cacheFragment = (fragment: DynamicFragment) => {
@@ -236,9 +237,13 @@ export const VaporKeepAliveImpl: ObjectVaporComponent = defineVaporComponent({
     const injectKeepAliveHooks = (frag: DynamicFragment) => {
       ;(frag.onBeforeTeardown || (frag.onBeforeTeardown = [])).push(
         (oldKey, nodes, scope) => {
-          processFragment(frag)
-          keptAliveScopes.set(oldKey, scope)
-          return true
+          // if the fragment's nodes include a component that should be cached
+          // return true to avoid tearing down the fragment's scope
+          if (processFragment(frag)) {
+            keptAliveScopes.set(oldKey, scope)
+            return true
+          }
+          return false
         },
       )
       ;(frag.onBeforeMount || (frag.onBeforeMount = [])).push(() =>

From d462cb430e7159205fb5e7ffdd3d046b73099fb5 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 22:20:45 +0800
Subject: [PATCH 12/13] chore(runtime-vapor): simplify HMR unregistering
 condition in unmountComponent

---
 packages/runtime-vapor/src/component.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/runtime-vapor/src/component.ts b/packages/runtime-vapor/src/component.ts
index 002783fe429..8ef656ea92b 100644
--- a/packages/runtime-vapor/src/component.ts
+++ b/packages/runtime-vapor/src/component.ts
@@ -920,7 +920,7 @@ export function unmountComponent(
   }
 
   if (instance.isMounted && !instance.isUnmounted) {
-    if (__DEV__ && instance.type.__hmrId) {
+    if (__DEV__) {
       unregisterHMR(instance)
     }
     if (instance.bum) {

From 3ddba38c19ab2267858dc03905afb68a0c2a2dd4 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Dec 2025 22:21:54 +0800
Subject: [PATCH 13/13] chore(test): add todo tests

---
 .../__tests__/transition.spec.ts              | 342 +++++++++++++++++-
 1 file changed, 340 insertions(+), 2 deletions(-)

diff --git a/packages-private/vapor-e2e-test/__tests__/transition.spec.ts b/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
index 27fe3ce6281..70660c72d8f 100644
--- a/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
+++ b/packages-private/vapor-e2e-test/__tests__/transition.spec.ts
@@ -937,11 +937,13 @@ describe('vapor transition', () => {
         await click(btnSwitchToB)
         await nextTick()
         await click(btnSwitchToC)
-        await transitionFinish(duration * 3)
+        await transitionFinish()
+        await transitionFinish()
         expect(await html(containerSelector)).toBe('<div class="">CompC</div>')
 
         await click(btnSwitchToA)
-        await transitionFinish(duration * 3)
+        await transitionFinish()
+        await transitionFinish()
         expect(await html(containerSelector)).toBe('<div class="">CompA</div>')
 
         let calls = await page().evaluate(() => {
@@ -958,6 +960,342 @@ describe('vapor transition', () => {
       },
       E2E_TIMEOUT,
     )
+
+    // #11775
+    // test(
+    //   'switch child then update include (out-in mode)',
+    //   async () => {
+    //     const onUpdatedSpyA = vi.fn()
+    //     const onUnmountedSpyC = vi.fn()
+
+    //     await page().exposeFunction('onUpdatedSpyA', onUpdatedSpyA)
+    //     await page().exposeFunction('onUnmountedSpyC', onUnmountedSpyC)
+
+    //     await page().evaluate(() => {
+    //       const { onUpdatedSpyA, onUnmountedSpyC } = window as any
+    //       const { createApp, ref, shallowRef, h, onUpdated, onUnmounted } = (
+    //         window as any
+    //       ).Vue
+    //       createApp({
+    //         template: `
+    //         <div id="container">
+    //           <transition mode="out-in">
+    //             <KeepAlive :include="includeRef">
+    //               <component :is="current" />
+    //             </KeepAlive>
+    //           </transition>
+    //         </div>
+    //         <button id="switchToB" @click="switchToB">switchToB</button>
+    //         <button id="switchToC" @click="switchToC">switchToC</button>
+    //         <button id="switchToA" @click="switchToA">switchToA</button>
+    //       `,
+    //         components: {
+    //           CompA: {
+    //             name: 'CompA',
+    //             setup() {
+    //               onUpdated(onUpdatedSpyA)
+    //               return () => h('div', 'CompA')
+    //             },
+    //           },
+    //           CompB: {
+    //             name: 'CompB',
+    //             setup() {
+    //               return () => h('div', 'CompB')
+    //             },
+    //           },
+    //           CompC: {
+    //             name: 'CompC',
+    //             setup() {
+    //               onUnmounted(onUnmountedSpyC)
+    //               return () => h('div', 'CompC')
+    //             },
+    //           },
+    //         },
+    //         setup: () => {
+    //           const includeRef = ref(['CompA', 'CompB', 'CompC'])
+    //           const current = shallowRef('CompA')
+    //           const switchToB = () => (current.value = 'CompB')
+    //           const switchToC = () => (current.value = 'CompC')
+    //           const switchToA = () => {
+    //             current.value = 'CompA'
+    //             includeRef.value = ['CompA']
+    //           }
+    //           return { current, switchToB, switchToC, switchToA, includeRef }
+    //         },
+    //       }).mount('#app')
+    //     })
+
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div>CompA</div>')
+
+    //     await click('#switchToB')
+    //     await nextTick()
+    //     await click('#switchToC')
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div class="">CompC</div>')
+
+    //     await click('#switchToA')
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div class="">CompA</div>')
+
+    //     // expect CompA only update once
+    //     expect(onUpdatedSpyA).toBeCalledTimes(1)
+    //     expect(onUnmountedSpyC).toBeCalledTimes(1)
+    //   },
+    //   E2E_TIMEOUT,
+    // )
+
+    // // #10827
+    // test(
+    //   'switch and update child then update include (out-in mode)',
+    //   async () => {
+    //     const onUnmountedSpyB = vi.fn()
+    //     await page().exposeFunction('onUnmountedSpyB', onUnmountedSpyB)
+
+    //     await page().evaluate(() => {
+    //       const { onUnmountedSpyB } = window as any
+    //       const {
+    //         createApp,
+    //         ref,
+    //         shallowRef,
+    //         h,
+    //         provide,
+    //         inject,
+    //         onUnmounted,
+    //       } = (window as any).Vue
+    //       createApp({
+    //         template: `
+    //         <div id="container">
+    //           <transition name="test-anim" mode="out-in">
+    //             <KeepAlive :include="includeRef">
+    //               <component :is="current" />
+    //             </KeepAlive>
+    //           </transition>
+    //         </div>
+    //         <button id="switchToA" @click="switchToA">switchToA</button>
+    //         <button id="switchToB" @click="switchToB">switchToB</button>
+    //       `,
+    //         components: {
+    //           CompA: {
+    //             name: 'CompA',
+    //             setup() {
+    //               const current = inject('current')
+    //               return () => h('div', current.value)
+    //             },
+    //           },
+    //           CompB: {
+    //             name: 'CompB',
+    //             setup() {
+    //               const current = inject('current')
+    //               onUnmounted(onUnmountedSpyB)
+    //               return () => h('div', current.value)
+    //             },
+    //           },
+    //         },
+    //         setup: () => {
+    //           const includeRef = ref(['CompA'])
+    //           const current = shallowRef('CompA')
+    //           provide('current', current)
+
+    //           const switchToB = () => {
+    //             current.value = 'CompB'
+    //             includeRef.value = ['CompA', 'CompB']
+    //           }
+    //           const switchToA = () => {
+    //             current.value = 'CompA'
+    //             includeRef.value = ['CompA']
+    //           }
+    //           return { current, switchToB, switchToA, includeRef }
+    //         },
+    //       }).mount('#app')
+    //     })
+
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div>CompA</div>')
+
+    //     await click('#switchToB')
+    //     await transitionFinish()
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div class="">CompB</div>')
+
+    //     await click('#switchToA')
+    //     await transitionFinish()
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div class="">CompA</div>')
+
+    //     expect(onUnmountedSpyB).toBeCalledTimes(1)
+    //   },
+    //   E2E_TIMEOUT,
+    // )
+
+    // // #12860
+    // test(
+    //   'unmount children',
+    //   async () => {
+    //     const unmountSpy = vi.fn()
+    //     let storageContainer: ElementHandle<HTMLDivElement>
+    //     const setStorageContainer = (container: any) =>
+    //       (storageContainer = container)
+    //     await page().exposeFunction('unmountSpy', unmountSpy)
+    //     await page().exposeFunction('setStorageContainer', setStorageContainer)
+    //     await page().evaluate(() => {
+    //       const { unmountSpy, setStorageContainer } = window as any
+    //       const { createApp, ref, h, onUnmounted, getCurrentInstance } = (
+    //         window as any
+    //       ).Vue
+    //       createApp({
+    //         template: `
+    //         <div id="container">
+    //           <transition>
+    //             <KeepAlive :include="includeRef">
+    //               <TrueBranch v-if="toggle"></TrueBranch>
+    //             </KeepAlive>
+    //           </transition>
+    //         </div>
+    //         <button id="toggleBtn" @click="click">button</button>
+    //       `,
+    //         components: {
+    //           TrueBranch: {
+    //             name: 'TrueBranch',
+    //             setup() {
+    //               const instance = getCurrentInstance()
+    //               onUnmounted(() => {
+    //                 unmountSpy()
+    //                 setStorageContainer(instance.__keepAliveStorageContainer)
+    //               })
+    //               const count = ref(0)
+    //               return () => h('div', count.value)
+    //             },
+    //           },
+    //         },
+    //         setup: () => {
+    //           const includeRef = ref(['TrueBranch'])
+    //           const toggle = ref(true)
+    //           const click = () => {
+    //             toggle.value = !toggle.value
+    //             if (toggle.value) {
+    //               includeRef.value = ['TrueBranch']
+    //             } else {
+    //               includeRef.value = []
+    //             }
+    //           }
+    //           return { toggle, click, unmountSpy, includeRef }
+    //         },
+    //       }).mount('#app')
+    //     })
+
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<div>0</div>')
+
+    //     await click('#toggleBtn')
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe('<!--v-if-->')
+    //     expect(unmountSpy).toBeCalledTimes(1)
+    //     expect(await storageContainer!.evaluate(x => x.innerHTML)).toBe(``)
+    //   },
+    //   E2E_TIMEOUT,
+    // )
+
+    // // #13153
+    // test(
+    //   'move kept-alive node before v-show transition leave finishes',
+    //   async () => {
+    //     await page().evaluate(() => {
+    //       const { createApp, ref } = (window as any).Vue
+    //       const show = ref(true)
+    //       createApp({
+    //         template: `
+    //         <div id="container">
+    //           <KeepAlive :include="['Comp1', 'Comp2']">
+    //             <component :is="state === 1 ? 'Comp1' : 'Comp2'"/>
+    //           </KeepAlive>
+    //         </div>
+    //         <button id="toggleBtn" @click="click">button</button>
+    //       `,
+    //         setup: () => {
+    //           const state = ref(1)
+    //           const click = () => (state.value = state.value === 1 ? 2 : 1)
+    //           return { state, click }
+    //         },
+    //         components: {
+    //           Comp1: {
+    //             components: {
+    //               Item: {
+    //                 name: 'Item',
+    //                 setup() {
+    //                   return { show }
+    //                 },
+    //                 template: `
+    //                   <Transition name="test">
+    //                     <div v-show="show" >
+    //                       <h2>{{ show ? "I should show" : "I shouldn't show " }}</h2>
+    //                     </div>
+    //                   </Transition>
+    //                 `,
+    //               },
+    //             },
+    //             name: 'Comp1',
+    //             setup() {
+    //               const toggle = () => (show.value = !show.value)
+    //               return { show, toggle }
+    //             },
+    //             template: `
+    //               <Item />
+    //               <h2>This is page1</h2>
+    //               <button id="changeShowBtn" @click="toggle">{{ show }}</button>
+    //             `,
+    //           },
+    //           Comp2: {
+    //             name: 'Comp2',
+    //             template: `<h2>This is page2</h2>`,
+    //           },
+    //         },
+    //       }).mount('#app')
+    //     })
+
+    //     expect(await html('#container')).toBe(
+    //       `<div><h2>I should show</h2></div>` +
+    //         `<h2>This is page1</h2>` +
+    //         `<button id="changeShowBtn">true</button>`,
+    //     )
+
+    //     // trigger v-show transition leave
+    //     await click('#changeShowBtn')
+    //     await nextTick()
+    //     expect(await html('#container')).toBe(
+    //       `<div class="test-leave-from test-leave-active"><h2>I shouldn't show </h2></div>` +
+    //         `<h2>This is page1</h2>` +
+    //         `<button id="changeShowBtn">false</button>`,
+    //     )
+
+    //     // switch to page2, before leave finishes
+    //     // expect v-show element's display to be none
+    //     await click('#toggleBtn')
+    //     await nextTick()
+    //     expect(await html('#container')).toBe(
+    //       `<div class="test-leave-from test-leave-active" style="display: none;"><h2>I shouldn't show </h2></div>` +
+    //         `<h2>This is page2</h2>`,
+    //     )
+
+    //     // switch back to page1
+    //     // expect v-show element's display to be none
+    //     await click('#toggleBtn')
+    //     await nextTick()
+    //     expect(await html('#container')).toBe(
+    //       `<div class="test-enter-from test-enter-active" style="display: none;"><h2>I shouldn't show </h2></div>` +
+    //         `<h2>This is page1</h2>` +
+    //         `<button id="changeShowBtn">false</button>`,
+    //     )
+
+    //     await transitionFinish()
+    //     expect(await html('#container')).toBe(
+    //       `<div class="" style="display: none;"><h2>I shouldn't show </h2></div>` +
+    //         `<h2>This is page1</h2>` +
+    //         `<button id="changeShowBtn">false</button>`,
+    //     )
+    //   },
+    //   E2E_TIMEOUT,
+    // )
   })
 
   describe.todo('transition with Suspense', () => {})