From 218bf7eda7900e5371917d9ded33d1ef037387bc Mon Sep 17 00:00:00 2001
From: HcySunYang <HcySunYang@outlook.com>
Date: Mon, 4 Jan 2021 18:27:39 +0800
Subject: [PATCH 1/3] fix(compiler-core): avoid generating useless createVNode
 helper

---
 .../__snapshots__/compile.spec.ts.snap        |  6 ++--
 .../__snapshots__/scopeId.spec.ts.snap        |  2 +-
 .../__snapshots__/hoistStatic.spec.ts.snap    |  8 ++---
 .../transformExpressions.spec.ts.snap         |  2 +-
 .../__snapshots__/vFor.spec.ts.snap           | 16 ++++-----
 .../transforms/__snapshots__/vIf.spec.ts.snap | 12 +++----
 .../__snapshots__/vModel.spec.ts.snap         | 16 ++++-----
 .../__snapshots__/vOnce.spec.ts.snap          |  2 +-
 .../__snapshots__/vSlot.spec.ts.snap          | 18 +++++-----
 packages/compiler-core/src/transform.ts       | 34 ++++++++++++++-----
 .../src/transforms/hoistStatic.ts             |  4 ++-
 packages/compiler-core/src/transforms/vFor.ts | 12 ++++++-
 packages/compiler-core/src/transforms/vIf.ts  | 14 +++++---
 .../__snapshots__/vModel.spec.ts.snap         | 26 +++++++-------
 .../__snapshots__/vShow.spec.ts.snap          |  2 +-
 .../templateTransformAssetUrl.spec.ts.snap    | 12 +++----
 .../__tests__/ssrComponent.spec.ts            |  2 +-
 .../src/transforms/ssrTransformComponent.ts   | 13 +++++--
 18 files changed, 121 insertions(+), 80 deletions(-)

diff --git a/packages/compiler-core/__tests__/__snapshots__/compile.spec.ts.snap b/packages/compiler-core/__tests__/__snapshots__/compile.spec.ts.snap
index 0534a5eb4d3..003033d1e6f 100644
--- a/packages/compiler-core/__tests__/__snapshots__/compile.spec.ts.snap
+++ b/packages/compiler-core/__tests__/__snapshots__/compile.spec.ts.snap
@@ -5,7 +5,7 @@ exports[`compiler: integration tests function mode 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { toDisplayString: _toDisplayString, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, createTextVNode: _createTextVNode, Fragment: _Fragment, renderList: _renderList } = _Vue
+    const { toDisplayString: _toDisplayString, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, createTextVNode: _createTextVNode, Fragment: _Fragment, renderList: _renderList, createVNode: _createVNode } = _Vue
 
     return (_openBlock(), _createBlock(\\"div\\", {
       id: \\"foo\\",
@@ -28,7 +28,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: integration tests function mode w/ prefixIdentifiers: true 1`] = `
-"const { toDisplayString: _toDisplayString, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, createTextVNode: _createTextVNode, Fragment: _Fragment, renderList: _renderList } = Vue
+"const { toDisplayString: _toDisplayString, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, createTextVNode: _createTextVNode, Fragment: _Fragment, renderList: _renderList, createVNode: _createVNode } = Vue
 
 return function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"div\\", {
@@ -51,7 +51,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: integration tests module mode 1`] = `
-"import { toDisplayString as _toDisplayString, createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock, createCommentVNode as _createCommentVNode, createTextVNode as _createTextVNode, Fragment as _Fragment, renderList as _renderList } from \\"vue\\"
+"import { toDisplayString as _toDisplayString, openBlock as _openBlock, createBlock as _createBlock, createCommentVNode as _createCommentVNode, createTextVNode as _createTextVNode, Fragment as _Fragment, renderList as _renderList, createVNode as _createVNode } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"div\\", {
diff --git a/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap b/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
index 7af32808b17..c6cbec65179 100644
--- a/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
+++ b/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
@@ -82,7 +82,7 @@ export const render = /*#__PURE__*/_withId((_ctx, _cache) => {
 `;
 
 exports[`scopeId compiler support should wrap render function 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock, withScopeId as _withScopeId } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock, withScopeId as _withScopeId } from \\"vue\\"
 const _withId = /*#__PURE__*/_withScopeId(\\"test\\")
 
 export const render = /*#__PURE__*/_withId((_ctx, _cache) => {
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/hoistStatic.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/hoistStatic.spec.ts.snap
index 003c4c63a16..022b243e367 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/hoistStatic.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/hoistStatic.spec.ts.snap
@@ -239,7 +239,7 @@ exports[`compiler: hoistStatic transform prefixIdentifiers should NOT hoist expr
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { toDisplayString: _toDisplayString, createTextVNode: _createTextVNode, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { toDisplayString: _toDisplayString, createTextVNode: _createTextVNode, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     const _component_Comp = _resolveComponent(\\"Comp\\")
 
@@ -276,7 +276,7 @@ exports[`compiler: hoistStatic transform prefixIdentifiers should NOT hoist keye
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"div\\", null, [
       (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (item) => {
@@ -308,7 +308,7 @@ exports[`compiler: hoistStatic transform should NOT hoist element with dynamic k
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"div\\", null, [
       (_openBlock(), _createBlock(\\"div\\", { key: foo }))
@@ -350,7 +350,7 @@ exports[`compiler: hoistStatic transform should NOT hoist root node 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"div\\"))
   }
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/transformExpressions.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/transformExpressions.spec.ts.snap
index 782d7a5e870..165df1e1ae8 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/transformExpressions.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/transformExpressions.spec.ts.snap
@@ -7,7 +7,7 @@ exports[`compiler: expression transform bindingMetadata inline mode 1`] = `
 `;
 
 exports[`compiler: expression transform bindingMetadata non-inline mode 1`] = `
-"const { toDisplayString: _toDisplayString, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache, $props, $setup, $data, $options) {
   return (_openBlock(), _createBlock(\\"div\\", null, _toDisplayString($props.props) + \\" \\" + _toDisplayString($setup.setup) + \\" \\" + _toDisplayString($data.data) + \\" \\" + _toDisplayString($options.options), 1 /* TEXT */))
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/vFor.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/vFor.spec.ts.snap
index aa98188dbf5..47c990674cc 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/vFor.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/vFor.spec.ts.snap
@@ -5,7 +5,7 @@ exports[`compiler: v-for codegen basic v-for 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (item) => {
       return (_openBlock(), _createBlock(\\"span\\"))
@@ -50,7 +50,7 @@ exports[`compiler: v-for codegen skipped key 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (item, __, index) => {
       return (_openBlock(), _createBlock(\\"span\\"))
@@ -64,7 +64,7 @@ exports[`compiler: v-for codegen skipped value & key 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (_, __, index) => {
       return (_openBlock(), _createBlock(\\"span\\"))
@@ -78,7 +78,7 @@ exports[`compiler: v-for codegen skipped value 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (_, key, index) => {
       return (_openBlock(), _createBlock(\\"span\\"))
@@ -109,7 +109,7 @@ exports[`compiler: v-for codegen template v-for key injection with single child
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (item) => {
       return (_openBlock(), _createBlock(\\"span\\", {
@@ -154,7 +154,7 @@ exports[`compiler: v-for codegen v-for on element with custom directive 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, resolveDirective: _resolveDirective, createVNode: _createVNode, withDirectives: _withDirectives } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, resolveDirective: _resolveDirective, withDirectives: _withDirectives } = _Vue
 
     const _directive_foo = _resolveDirective(\\"foo\\")
 
@@ -186,7 +186,7 @@ exports[`compiler: v-for codegen v-if + v-for 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode, createCommentVNode: _createCommentVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
 
     return ok
       ? (_openBlock(true), _createBlock(_Fragment, { key: 0 }, _renderList(list, (i) => {
@@ -218,7 +218,7 @@ exports[`compiler: v-for codegen value + key + index 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode } = _Vue
+    const { renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(true), _createBlock(_Fragment, null, _renderList(items, (item, key, index) => {
       return (_openBlock(), _createBlock(\\"span\\"))
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/vIf.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/vIf.spec.ts.snap
index def7f945a51..3c5f03209a5 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/vIf.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/vIf.spec.ts.snap
@@ -5,7 +5,7 @@ exports[`compiler: v-if codegen basic v-if 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
 
     return ok
       ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
@@ -19,7 +19,7 @@ exports[`compiler: v-if codegen increasing key: v-if + v-else-if + v-else 1`] =
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
 
     return (_openBlock(), _createBlock(_Fragment, null, [
       ok
@@ -40,7 +40,7 @@ exports[`compiler: v-if codegen multiple v-if that are sibling nodes should have
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
 
     return (_openBlock(), _createBlock(_Fragment, null, [
       ok
@@ -91,7 +91,7 @@ exports[`compiler: v-if codegen v-if + v-else 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
 
     return ok
       ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
@@ -105,7 +105,7 @@ exports[`compiler: v-if codegen v-if + v-else-if + v-else 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode, Fragment: _Fragment } = _Vue
 
     return ok
       ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
@@ -121,7 +121,7 @@ exports[`compiler: v-if codegen v-if + v-else-if 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = _Vue
 
     return ok
       ? (_openBlock(), _createBlock(\\"div\\", { key: 0 }))
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/vModel.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
index bef1bd699b7..d3bc85bf756 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`compiler: transform v-model compound expression (with prefixIdentifiers) 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"input\\", {
@@ -16,7 +16,7 @@ exports[`compiler: transform v-model compound expression 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"input\\", {
       modelValue: model[index],
@@ -31,7 +31,7 @@ exports[`compiler: transform v-model simple expression (with multilines) 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"input\\", {
       modelValue: 
@@ -50,7 +50,7 @@ foo
 `;
 
 exports[`compiler: transform v-model simple expression (with prefixIdentifiers) 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"input\\", {
@@ -65,7 +65,7 @@ exports[`compiler: transform v-model simple expression 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"input\\", {
       modelValue: model,
@@ -80,7 +80,7 @@ exports[`compiler: transform v-model with argument 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"input\\", {
       value: model,
@@ -91,7 +91,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform v-model with dynamic argument (with prefixIdentifiers) 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"input\\", {
@@ -106,7 +106,7 @@ exports[`compiler: transform v-model with dynamic argument 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"input\\", {
       [value]: model,
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/vOnce.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/vOnce.spec.ts.snap
index 1fc484fe52c..f4897194f03 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/vOnce.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/vOnce.spec.ts.snap
@@ -62,7 +62,7 @@ exports[`compiler: v-once transform on slot outlet 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { setBlockTracking: _setBlockTracking, renderSlot: _renderSlot, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { setBlockTracking: _setBlockTracking, renderSlot: _renderSlot, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return (_openBlock(), _createBlock(\\"div\\", null, [
       _cache[1] || (
diff --git a/packages/compiler-core/__tests__/transforms/__snapshots__/vSlot.spec.ts.snap b/packages/compiler-core/__tests__/transforms/__snapshots__/vSlot.spec.ts.snap
index a93b36bc369..5bb9ea6e1d9 100644
--- a/packages/compiler-core/__tests__/transforms/__snapshots__/vSlot.spec.ts.snap
+++ b/packages/compiler-core/__tests__/transforms/__snapshots__/vSlot.spec.ts.snap
@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`compiler: transform component slots dynamically named slots 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -30,7 +30,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots named slot with v-for w/ prefixIdentifiers: true 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, renderList: _renderList, createSlots: _createSlots, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, renderList: _renderList, createSlots: _createSlots, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -47,7 +47,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots named slot with v-if + prefixIdentifiers: true 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -68,7 +68,7 @@ exports[`compiler: transform component slots named slot with v-if + v-else-if +
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     const _component_Comp = _resolveComponent(\\"Comp\\")
 
@@ -97,7 +97,7 @@ exports[`compiler: transform component slots named slot with v-if 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { resolveComponent: _resolveComponent, withCtx: _withCtx, createSlots: _createSlots, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     const _component_Comp = _resolveComponent(\\"Comp\\")
 
@@ -158,7 +158,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots on component dynamically named slot 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -171,7 +171,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots on component named slot 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -184,7 +184,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots on-component default slot 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
@@ -197,7 +197,7 @@ return function render(_ctx, _cache) {
 `;
 
 exports[`compiler: transform component slots template named slots 1`] = `
-"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, createVNode: _createVNode, openBlock: _openBlock, createBlock: _createBlock } = Vue
+"const { toDisplayString: _toDisplayString, resolveComponent: _resolveComponent, withCtx: _withCtx, openBlock: _openBlock, createBlock: _createBlock } = Vue
 
 return function render(_ctx, _cache) {
   const _component_Comp = _resolveComponent(\\"Comp\\")
diff --git a/packages/compiler-core/src/transform.ts b/packages/compiler-core/src/transform.ts
index 87daf363eb4..a582a4049f4 100644
--- a/packages/compiler-core/src/transform.ts
+++ b/packages/compiler-core/src/transform.ts
@@ -35,7 +35,8 @@ import {
   helperNameMap,
   CREATE_BLOCK,
   CREATE_COMMENT,
-  OPEN_BLOCK
+  OPEN_BLOCK,
+  CREATE_VNODE
 } from './runtimeHelpers'
 import { isVSlot } from './utils'
 import { hoistStatic, isSingleElementRoot } from './transforms/hoistStatic'
@@ -85,7 +86,7 @@ export interface TransformContext
   extends Required<Omit<TransformOptions, 'filename'>> {
   selfName: string | null
   root: RootNode
-  helpers: Set<symbol>
+  helpers: Map<symbol, number>
   components: Set<string>
   directives: Set<string>
   hoists: (JSChildNode | null)[]
@@ -103,6 +104,7 @@ export interface TransformContext
   childIndex: number
   currentNode: RootNode | TemplateChildNode | null
   helper<T extends symbol>(name: T): T
+  removeHelper<T extends symbol>(name: T): void
   helperString(name: symbol): string
   replaceNode(node: TemplateChildNode): void
   removeNode(node?: TemplateChildNode): void
@@ -159,7 +161,7 @@ export function createTransformContext(
 
     // state
     root,
-    helpers: new Set(),
+    helpers: new Map(),
     components: new Set(),
     directives: new Set(),
     hoists: [],
@@ -180,9 +182,20 @@ export function createTransformContext(
 
     // methods
     helper(name) {
-      context.helpers.add(name)
+      const count = context.helpers.get(name) || 0
+      context.helpers.set(name, count + 1)
       return name
     },
+    removeHelper(name) {
+      const count = context.helpers.get(name)
+      if (count) {
+        const currentCount = count - 1
+        context.helpers.set(name, currentCount)
+        if (!currentCount) {
+          context.helpers.delete(name)
+        }
+      }
+    },
     helperString(name) {
       return `_${helperNameMap[context.helper(name)]}`
     },
@@ -290,7 +303,7 @@ export function transform(root: RootNode, options: TransformOptions) {
     createRootCodegen(root, context)
   }
   // finalize meta information
-  root.helpers = [...context.helpers]
+  root.helpers = [...context.helpers.keys()]
   root.components = [...context.components]
   root.directives = [...context.directives]
   root.imports = context.imports
@@ -300,7 +313,7 @@ export function transform(root: RootNode, options: TransformOptions) {
 }
 
 function createRootCodegen(root: RootNode, context: TransformContext) {
-  const { helper } = context
+  const { helper, removeHelper } = context
   const { children } = root
   if (children.length === 1) {
     const child = children[0]
@@ -310,9 +323,12 @@ function createRootCodegen(root: RootNode, context: TransformContext) {
       // SimpleExpressionNode
       const codegenNode = child.codegenNode
       if (codegenNode.type === NodeTypes.VNODE_CALL) {
-        codegenNode.isBlock = true
-        helper(OPEN_BLOCK)
-        helper(CREATE_BLOCK)
+        if (!codegenNode.isBlock) {
+          removeHelper(CREATE_VNODE)
+          codegenNode.isBlock = true
+          helper(OPEN_BLOCK)
+          helper(CREATE_BLOCK)
+        }
       }
       root.codegenNode = codegenNode
     } else {
diff --git a/packages/compiler-core/src/transforms/hoistStatic.ts b/packages/compiler-core/src/transforms/hoistStatic.ts
index 004a1e5a116..de81bea6bd1 100644
--- a/packages/compiler-core/src/transforms/hoistStatic.ts
+++ b/packages/compiler-core/src/transforms/hoistStatic.ts
@@ -14,7 +14,7 @@ import {
 import { TransformContext } from '../transform'
 import { PatchFlags, isString, isSymbol } from '@vue/shared'
 import { isSlotOutlet } from '../utils'
-import { CREATE_VNODE } from '../runtimeHelpers'
+import { CREATE_BLOCK, CREATE_VNODE, OPEN_BLOCK } from '../runtimeHelpers'
 
 export function hoistStatic(root: RootNode, context: TransformContext) {
   walk(
@@ -205,6 +205,8 @@ export function getConstantType(
         // static then they don't need to be blocks since there will be no
         // nested updates.
         if (codegenNode.isBlock) {
+          context.removeHelper(OPEN_BLOCK)
+          context.removeHelper(CREATE_BLOCK)
           codegenNode.isBlock = false
           context.helper(CREATE_VNODE)
         }
diff --git a/packages/compiler-core/src/transforms/vFor.ts b/packages/compiler-core/src/transforms/vFor.ts
index e42cfc7797e..4060912c648 100644
--- a/packages/compiler-core/src/transforms/vFor.ts
+++ b/packages/compiler-core/src/transforms/vFor.ts
@@ -48,7 +48,7 @@ import { PatchFlags, PatchFlagNames } from '@vue/shared'
 export const transformFor = createStructuralDirectiveTransform(
   'for',
   (node, dir, context) => {
-    const { helper } = context
+    const { helper, removeHelper } = context
     return processFor(node, dir, context, forNode => {
       // create the loop render function expression now, and add the
       // iterator on exit after all children have been traversed
@@ -166,6 +166,16 @@ export const transformFor = createStructuralDirectiveTransform(
           if (isTemplate && keyProperty) {
             injectProp(childBlock, keyProperty, context)
           }
+          if (childBlock.isBlock !== !isStableFragment) {
+            if (childBlock.isBlock) {
+              // switch from block to vnode
+              removeHelper(OPEN_BLOCK)
+              removeHelper(CREATE_BLOCK)
+            } else {
+              // switch from vnode to block
+              removeHelper(CREATE_VNODE)
+            }
+          }
           childBlock.isBlock = !isStableFragment
           if (childBlock.isBlock) {
             helper(OPEN_BLOCK)
diff --git a/packages/compiler-core/src/transforms/vIf.ts b/packages/compiler-core/src/transforms/vIf.ts
index a9ea7acfb47..b5ee70899c5 100644
--- a/packages/compiler-core/src/transforms/vIf.ts
+++ b/packages/compiler-core/src/transforms/vIf.ts
@@ -31,7 +31,8 @@ import {
   CREATE_BLOCK,
   FRAGMENT,
   CREATE_COMMENT,
-  OPEN_BLOCK
+  OPEN_BLOCK,
+  CREATE_VNODE
 } from '../runtimeHelpers'
 import { injectProp, findDir, findProp } from '../utils'
 import { PatchFlags, PatchFlagNames } from '@vue/shared'
@@ -225,7 +226,7 @@ function createChildrenCodegenNode(
   keyIndex: number,
   context: TransformContext
 ): BlockCodegenNode {
-  const { helper } = context
+  const { helper, removeHelper } = context
   const keyProperty = createObjectProperty(
     `key`,
     createSimpleExpression(
@@ -267,9 +268,12 @@ function createChildrenCodegenNode(
       .codegenNode as BlockCodegenNode
     // Change createVNode to createBlock.
     if (vnodeCall.type === NodeTypes.VNODE_CALL) {
-      vnodeCall.isBlock = true
-      helper(OPEN_BLOCK)
-      helper(CREATE_BLOCK)
+      if (!vnodeCall.isBlock) {
+        removeHelper(CREATE_VNODE)
+        vnodeCall.isBlock = true
+        helper(OPEN_BLOCK)
+        helper(CREATE_BLOCK)
+      }
     }
     // inject branch key
     injectProp(vnodeCall, keyProperty, context)
diff --git a/packages/compiler-dom/__tests__/transforms/__snapshots__/vModel.spec.ts.snap b/packages/compiler-dom/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
index c6e4532d080..8070ff942d7 100644
--- a/packages/compiler-dom/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
+++ b/packages/compiler-dom/__tests__/transforms/__snapshots__/vModel.spec.ts.snap
@@ -5,7 +5,7 @@ exports[`compiler: transform v-model errors should allow usage on custom element
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"my-input\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -21,7 +21,7 @@ exports[`compiler: transform v-model input w/ dynamic v-bind 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelDynamic: _vModelDynamic, mergeProps: _mergeProps, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelDynamic: _vModelDynamic, mergeProps: _mergeProps, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", _mergeProps(obj, {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -37,7 +37,7 @@ exports[`compiler: transform v-model input w/ dynamic v-bind 2`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelDynamic: _vModelDynamic, resolveDirective: _resolveDirective, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelDynamic: _vModelDynamic, resolveDirective: _resolveDirective, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     const _directive_bind = _resolveDirective(\\"bind\\")
 
@@ -56,7 +56,7 @@ exports[`compiler: transform v-model modifiers .lazy 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -77,7 +77,7 @@ exports[`compiler: transform v-model modifiers .number 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -98,7 +98,7 @@ exports[`compiler: transform v-model modifiers .trim 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -119,7 +119,7 @@ exports[`compiler: transform v-model simple expression 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -135,7 +135,7 @@ exports[`compiler: transform v-model simple expression for input (checkbox) 1`]
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelCheckbox: _vModelCheckbox, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelCheckbox: _vModelCheckbox, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       type: \\"checkbox\\",
@@ -152,7 +152,7 @@ exports[`compiler: transform v-model simple expression for input (dynamic type)
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelDynamic: _vModelDynamic, resolveDirective: _resolveDirective, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelDynamic: _vModelDynamic, resolveDirective: _resolveDirective, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     const _directive_bind = _resolveDirective(\\"bind\\")
 
@@ -171,7 +171,7 @@ exports[`compiler: transform v-model simple expression for input (radio) 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelRadio: _vModelRadio, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelRadio: _vModelRadio, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       type: \\"radio\\",
@@ -188,7 +188,7 @@ exports[`compiler: transform v-model simple expression for input (text) 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"input\\", {
       type: \\"text\\",
@@ -205,7 +205,7 @@ exports[`compiler: transform v-model simple expression for select 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelSelect: _vModelSelect, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelSelect: _vModelSelect, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"select\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
@@ -221,7 +221,7 @@ exports[`compiler: transform v-model simple expression for textarea 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vModelText: _vModelText, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vModelText: _vModelText, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"textarea\\", {
       \\"onUpdate:modelValue\\": $event => (model = $event)
diff --git a/packages/compiler-dom/__tests__/transforms/__snapshots__/vShow.spec.ts.snap b/packages/compiler-dom/__tests__/transforms/__snapshots__/vShow.spec.ts.snap
index 79940f10655..954a8d07940 100644
--- a/packages/compiler-dom/__tests__/transforms/__snapshots__/vShow.spec.ts.snap
+++ b/packages/compiler-dom/__tests__/transforms/__snapshots__/vShow.spec.ts.snap
@@ -5,7 +5,7 @@ exports[`compiler: v-show transform simple expression 1`] = `
 
 return function render(_ctx, _cache) {
   with (_ctx) {
-    const { vShow: _vShow, createVNode: _createVNode, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
+    const { vShow: _vShow, withDirectives: _withDirectives, openBlock: _openBlock, createBlock: _createBlock } = _Vue
 
     return _withDirectives((_openBlock(), _createBlock(\\"div\\", null, null, 512 /* NEED_PATCH */)), [
       [_vShow, a]
diff --git a/packages/compiler-sfc/__tests__/__snapshots__/templateTransformAssetUrl.spec.ts.snap b/packages/compiler-sfc/__tests__/__snapshots__/templateTransformAssetUrl.spec.ts.snap
index 1159b636290..c1d8c39fa6c 100644
--- a/packages/compiler-sfc/__tests__/__snapshots__/templateTransformAssetUrl.spec.ts.snap
+++ b/packages/compiler-sfc/__tests__/__snapshots__/templateTransformAssetUrl.spec.ts.snap
@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`compiler sfc: transform asset url should allow for full base URLs, with paths 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"img\\", { src: \\"http://localhost:3000/src/logo.png\\" }))
@@ -9,7 +9,7 @@ export function render(_ctx, _cache) {
 `;
 
 exports[`compiler sfc: transform asset url should allow for full base URLs, without paths 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"img\\", { src: \\"http://localhost:3000/logo.png\\" }))
@@ -17,7 +17,7 @@ export function render(_ctx, _cache) {
 `;
 
 exports[`compiler sfc: transform asset url should allow for full base URLs, without port 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"img\\", { src: \\"http://localhost/logo.png\\" }))
@@ -25,7 +25,7 @@ export function render(_ctx, _cache) {
 `;
 
 exports[`compiler sfc: transform asset url should allow for full base URLs, without protocol 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"img\\", { src: \\"//localhost/logo.png\\" }))
@@ -33,7 +33,7 @@ export function render(_ctx, _cache) {
 `;
 
 exports[`compiler sfc: transform asset url support uri fragment 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 import _imports_0 from '@svg/file.svg'
 
 
@@ -45,7 +45,7 @@ export function render(_ctx, _cache) {
 `;
 
 exports[`compiler sfc: transform asset url support uri is empty 1`] = `
-"import { createVNode as _createVNode, openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
+"import { openBlock as _openBlock, createBlock as _createBlock } from \\"vue\\"
 
 export function render(_ctx, _cache) {
   return (_openBlock(), _createBlock(\\"use\\", { href: '' }))
diff --git a/packages/compiler-ssr/__tests__/ssrComponent.spec.ts b/packages/compiler-ssr/__tests__/ssrComponent.spec.ts
index fabc9ecfb2e..ed4ce384966 100644
--- a/packages/compiler-ssr/__tests__/ssrComponent.spec.ts
+++ b/packages/compiler-ssr/__tests__/ssrComponent.spec.ts
@@ -207,7 +207,7 @@ describe('ssr: components', () => {
         </template>
       </foo>`).code
       ).toMatchInlineSnapshot(`
-        "const { resolveComponent: _resolveComponent, withCtx: _withCtx, renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createVNode: _createVNode, createCommentVNode: _createCommentVNode } = require(\\"vue\\")
+        "const { resolveComponent: _resolveComponent, withCtx: _withCtx, renderList: _renderList, Fragment: _Fragment, openBlock: _openBlock, createBlock: _createBlock, createCommentVNode: _createCommentVNode } = require(\\"vue\\")
         const { ssrRenderComponent: _ssrRenderComponent, ssrRenderList: _ssrRenderList } = require(\\"@vue/server-renderer\\")
 
         return function ssrRender(_ctx, _push, _parent, _attrs) {
diff --git a/packages/compiler-ssr/src/transforms/ssrTransformComponent.ts b/packages/compiler-ssr/src/transforms/ssrTransformComponent.ts
index 5acf8000b17..b3fefb126c0 100644
--- a/packages/compiler-ssr/src/transforms/ssrTransformComponent.ts
+++ b/packages/compiler-ssr/src/transforms/ssrTransformComponent.ts
@@ -291,8 +291,17 @@ function subTransform(
   traverseNode(childRoot, childContext)
   // merge helpers/components/directives into parent context
   ;(['helpers', 'components', 'directives'] as const).forEach(key => {
-    childContext[key].forEach((value: any) => {
-      ;(parentContext[key] as any).add(value)
+    childContext[key].forEach((value: any, helperKey: any) => {
+      if (key === 'helpers') {
+        const parentCount = parentContext.helpers.get(helperKey)
+        if (parentCount === undefined) {
+          parentContext.helpers.set(helperKey, value)
+        } else {
+          parentContext.helpers.set(helperKey, value + parentCount)
+        }
+      } else {
+        ;(parentContext[key] as any).add(value)
+      }
     })
   })
   // imports/hoists are not merged because:

From 861d7247fade2843d068c54f845d5b0d916efb46 Mon Sep 17 00:00:00 2001
From: HcySunYang <HcySunYang@outlook.com>
Date: Fri, 5 Feb 2021 07:39:53 +0800
Subject: [PATCH 2/3] chore: simplify the code

---
 packages/compiler-core/src/transform.ts      |  3 ++-
 packages/compiler-core/src/transforms/vIf.ts | 12 +++++-------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/packages/compiler-core/src/transform.ts b/packages/compiler-core/src/transform.ts
index a582a4049f4..ff41715c15f 100644
--- a/packages/compiler-core/src/transform.ts
+++ b/packages/compiler-core/src/transform.ts
@@ -190,9 +190,10 @@ export function createTransformContext(
       const count = context.helpers.get(name)
       if (count) {
         const currentCount = count - 1
-        context.helpers.set(name, currentCount)
         if (!currentCount) {
           context.helpers.delete(name)
+        } else {
+          context.helpers.set(name, currentCount)
         }
       }
     },
diff --git a/packages/compiler-core/src/transforms/vIf.ts b/packages/compiler-core/src/transforms/vIf.ts
index b5ee70899c5..9f10451e8d5 100644
--- a/packages/compiler-core/src/transforms/vIf.ts
+++ b/packages/compiler-core/src/transforms/vIf.ts
@@ -267,13 +267,11 @@ function createChildrenCodegenNode(
     const vnodeCall = (firstChild as ElementNode)
       .codegenNode as BlockCodegenNode
     // Change createVNode to createBlock.
-    if (vnodeCall.type === NodeTypes.VNODE_CALL) {
-      if (!vnodeCall.isBlock) {
-        removeHelper(CREATE_VNODE)
-        vnodeCall.isBlock = true
-        helper(OPEN_BLOCK)
-        helper(CREATE_BLOCK)
-      }
+    if (vnodeCall.type === NodeTypes.VNODE_CALL && !vnodeCall.isBlock) {
+      removeHelper(CREATE_VNODE)
+      vnodeCall.isBlock = true
+      helper(OPEN_BLOCK)
+      helper(CREATE_BLOCK)
     }
     // inject branch key
     injectProp(vnodeCall, keyProperty, context)

From 20b9fa3e3d6cb7f352c6a9be345be661fcba8f82 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Thu, 25 Mar 2021 16:55:09 -0400
Subject: [PATCH 3/3] chore: fix test

---
 .../__tests__/__snapshots__/scopeId.spec.ts.snap       | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap b/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
index 2585e7ce322..4076e61db6a 100644
--- a/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
+++ b/packages/compiler-core/__tests__/__snapshots__/scopeId.spec.ts.snap
@@ -74,15 +74,5 @@ export function render(_ctx, _cache) {
     ]),
     _: 1 /* STABLE */
   }))
-})"
-`;
-
-exports[`scopeId compiler support should wrap render function 1`] = `
-"import { openBlock as _openBlock, createBlock as _createBlock, withScopeId as _withScopeId } from \\"vue\\"
-const _withId = /*#__PURE__*/_withScopeId(\\"test\\")
-
-export const render = /*#__PURE__*/_withId((_ctx, _cache) => {
-  return (_openBlock(), _createBlock(\\"div\\"))
-})"
 }"
 `;