chore: improve code

Author: edison1105

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

@@ -767,12 +767,10 @@ describe('renderer: optimized mode', () => {
 
     show.value = false
     await nextTick()
-    expect(block!.dynamicChildren).toBe(null)
     expect(inner(root)).toBe('<div>foo</div>')
 
     show.value = true
     await nextTick()
-    expect(block!.dynamicChildren).toBe(null)
     expect(inner(root)).toBe('<div><!--comment--><div>bar</div></div>')
   })
 

packages/runtime-core/src/helpers/renderSlot.ts

@@ -11,8 +11,7 @@ import {
   openBlock,
   createBlock,
   Fragment,
-  VNode,
-  setBlockTracking
+  VNode
 } from '../vnode'
 import { PatchFlags, SlotFlags } from '@vue/shared'
 import { warn } from '../warning'
@@ -39,7 +38,14 @@ export function renderSlot(
       currentRenderingInstance!.parent.isCE)
   ) {
     if (name !== 'default') props.name = name
-    return createVNode('slot', props, fallback && getFallbackVNode(fallback))
+    let renderFallback = false
+    const node = createVNode(
+      'slot',
+      props,
+      fallback && ((renderFallback = true), fallback())
+    )
+    if (renderFallback) node.patchFlag = PatchFlags.BAIL
+    return node
   }
 
   let slot = slots[name]
@@ -60,6 +66,7 @@ export function renderSlot(
   if (slot && (slot as ContextualRenderFn)._c) {
     ;(slot as ContextualRenderFn)._d = false
   }
+  let renderFallback = false
   openBlock()
   const validSlotContent = slot && ensureValidVNode(slot(props))
   const rendered = createBlock(
@@ -72,7 +79,7 @@ export function renderSlot(
         (validSlotContent && (validSlotContent as any).key) ||
         `_${name}`
     },
-    validSlotContent || (fallback ? getFallbackVNode(fallback) : []),
+    validSlotContent || (fallback ? ((renderFallback = true), fallback()) : []),
     validSlotContent && (slots as RawSlots)._ === SlotFlags.STABLE
       ? PatchFlags.STABLE_FRAGMENT
       : PatchFlags.BAIL
@@ -83,16 +90,10 @@ export function renderSlot(
   if (slot && (slot as ContextualRenderFn)._c) {
     ;(slot as ContextualRenderFn)._d = true
   }
+  if (renderFallback) rendered.patchFlag = PatchFlags.BAIL
   return rendered
 }
 
-function getFallbackVNode(fallback: () => VNodeArrayChildren) {
-  setBlockTracking(-1)
-  const vnode = fallback()
-  setBlockTracking(1)
-  return vnode
-}
-
 function ensureValidVNode(vnodes: VNodeArrayChildren) {
   return vnodes.some(child => {
     if (!isVNode(child)) return true

packages/runtime-core/src/renderer.ts

@@ -825,7 +825,7 @@ function baseCreateRenderer(
     }
 
     const areChildrenSVG = isSVG && n2.type !== 'foreignObject'
-    if (dynamicChildren) {
+    if (optimized && dynamicChildren) {
       patchBlockChildren(
         n1.dynamicChildren!,
         dynamicChildren,
@@ -1058,9 +1058,10 @@ function baseCreateRenderer(
     let { patchFlag, dynamicChildren, slotScopeIds: fragmentSlotScopeIds } = n2
 
     if (
-      __DEV__ &&
-      // #5523 dev root fragment may inherit directives
-      (isHmrUpdating || patchFlag & PatchFlags.DEV_ROOT_FRAGMENT)
+      (__DEV__ &&
+        // #5523 dev root fragment may inherit directives
+        (isHmrUpdating || patchFlag & PatchFlags.DEV_ROOT_FRAGMENT)) ||
+      (n1 || n2).patchFlag === PatchFlags.BAIL
     ) {
       // HMR updated / Dev root fragment (w/ comments), force full diff
       patchFlag = 0
@@ -1093,6 +1094,7 @@ function baseCreateRenderer(
       )
     } else {
       if (
+        optimized &&
         patchFlag > 0 &&
         patchFlag & PatchFlags.STABLE_FRAGMENT &&
         dynamicChildren &&