fix(compiler-core): update code and test

packages/runtime-dom/__tests__/helpers/useCssVars.spec.ts

@@ -16,7 +16,8 @@ import {
   createElementBlock,
   createCommentVNode,
   createVNode,
-  Transition
+  Transition,
+  createBlock
 } from '@vue/runtime-dom'
 
 describe('useCssVars', () => {
@@ -309,8 +310,7 @@ describe('useCssVars', () => {
                       createElementBlock(
                         'div',
                         {
-                          key: 0,
-                          class: 'text'
+                          key: 0
                         },
                         ' test '
                       ))
@@ -360,8 +360,7 @@ describe('useCssVars', () => {
                     createElementBlock(
                       'div',
                       {
-                        key: 0,
-                        class: 'text'
+                        key: 0
                       },
                       'test'
                     ))
@@ -390,4 +389,70 @@ describe('useCssVars', () => {
       expect((c as HTMLElement).style.getPropertyValue(`--color`)).toBe('red')
     }
   })
+
+  test('with teleport(transition & v-if element)', async () => {
+    document.body.innerHTML = ''
+    const state = reactive({ color: 'red' })
+    const root = document.createElement('div')
+    const target = document.body
+    const toggle = ref(true)
+
+    const App = {
+      setup() {
+        useCssVars(() => state)
+        return () => [
+          (openBlock(),
+          createBlock(Teleport, { to: target }, [
+            createVNode(
+              Transition,
+              {},
+              {
+                default: withCtx(() => [
+                  toggle.value
+                    ? (openBlock(),
+                      createElementBlock(
+                        'div',
+                        {
+                          key: 0
+                        },
+                        'test'
+                      ))
+                    : createCommentVNode('v-if', true)
+                ]),
+                _: 1 /* STABLE */
+              }
+            )
+          ])),
+          (openBlock(),
+          createBlock(Teleport, { to: target }, [
+            toggle.value
+              ? (openBlock(),
+                createElementBlock(
+                  'div',
+                  {
+                    key: 0
+                  },
+                  'element'
+                ))
+              : createCommentVNode('v-if', true)
+          ]))
+        ]
+      }
+    }
+
+    render(h(App), root)
+    await nextTick()
+    expect(target.children.length).toBe(2)
+    for (const c of [].slice.call(target.children as any)) {
+      expect((c as HTMLElement).style.getPropertyValue(`--color`)).toBe('red')
+    }
+    toggle.value = false
+    await nextTick()
+    toggle.value = true
+    await nextTick()
+    expect(target.children.length).toBe(2)
+    for (const c of [].slice.call(target.children as any)) {
+      expect((c as HTMLElement).style.getPropertyValue(`--color`)).toBe('red')
+    }
+  })
 })

packages/runtime-dom/src/helpers/useCssVars.ts

@@ -9,7 +9,8 @@ import {
   onUnmounted,
   resolveTarget,
   TeleportProps,
-  updateCssVars
+  updateCssVars,
+  onUpdated
 } from '@vue/runtime-core'
 import { ShapeFlags, isArray } from '@vue/shared'
 import { nodeOps } from '../nodeOps'
@@ -46,21 +47,28 @@ export function useCssVars(getter: (ctx: any) => Record<string, string>) {
 
   onMounted(() => {
     const obs = [onSubTreeChange(instance.subTree.el!.parentNode, setVars)]
-    const observeTeleportTarget = (vnode: VNode) => {
+    const observeTeleportTarget = (vnode: VNode, init = true) => {
       if (vnode.shapeFlag & ShapeFlags.TELEPORT) {
         const target = resolveTarget(
           vnode.props as TeleportProps,
           nodeOps.querySelector
         ) as Node
         if (target) {
-          obs.push(onSubTreeChange(target, () => updateCssVars(vnode)))
+          if (init) {
+            obs.push(onSubTreeChange(target, () => updateCssVars(vnode)))
+          } else {
+            updateCssVars(vnode)
+          }
         }
       }
       if (isArray(vnode.children)) {
-        vnode.children.forEach(n => observeTeleportTarget(n as VNode))
+        vnode.children.forEach(n => observeTeleportTarget(n as VNode, init))
       }
     }
     observeTeleportTarget(instance.subTree)
+    onUpdated(() => {
+      observeTeleportTarget(instance.subTree, false)
+    })
     onUnmounted(() => obs.forEach(ob => ob.disconnect()))
   })
 }