From c3aa9e7458966dee16a488885537f3530b400e49 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Feb 2021 18:00:18 +0800
Subject: [PATCH 1/2] chore(runtime-core): extract function isReservedKey

---
 packages/runtime-core/src/componentOptions.ts        |  5 +++--
 packages/runtime-core/src/componentPublicInstance.ts | 10 ++++------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/packages/runtime-core/src/componentOptions.ts b/packages/runtime-core/src/componentOptions.ts
index c836f125493..907ca5ec510 100644
--- a/packages/runtime-core/src/componentOptions.ts
+++ b/packages/runtime-core/src/componentOptions.ts
@@ -54,7 +54,8 @@ import { EmitsOptions } from './componentEmits'
 import { Directive } from './directives'
 import {
   CreateComponentPublicInstance,
-  ComponentPublicInstance
+  ComponentPublicInstance,
+  isReservedKey
 } from './componentPublicInstance'
 import { warn } from './warning'
 import { VNodeChild } from './vnode'
@@ -640,7 +641,7 @@ export function applyOptions(
       for (const key in rawData) {
         checkDuplicateProperties!(OptionTypes.DATA, key)
         // expose data on ctx during dev
-        if (key[0] !== '$' && key[0] !== '_') {
+        if (!isReservedKey(key)) {
           Object.defineProperty(ctx, key, {
             configurable: true,
             enumerable: true,
diff --git a/packages/runtime-core/src/componentPublicInstance.ts b/packages/runtime-core/src/componentPublicInstance.ts
index c493fea0b90..4cc5bd2cf84 100644
--- a/packages/runtime-core/src/componentPublicInstance.ts
+++ b/packages/runtime-core/src/componentPublicInstance.ts
@@ -247,6 +247,8 @@ export interface ComponentRenderContext {
   _: ComponentInternalInstance
 }
 
+export const isReservedKey = (key: string) => key[0] === '_' || key[0] === '$'
+
 export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
   get({ _: instance }: ComponentRenderContext, key: string) {
     const {
@@ -345,11 +347,7 @@ export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
         // to infinite warning loop
         key.indexOf('__v') !== 0)
     ) {
-      if (
-        data !== EMPTY_OBJ &&
-        (key[0] === '$' || key[0] === '_') &&
-        hasOwn(data, key)
-      ) {
+      if (data !== EMPTY_OBJ && isReservedKey(key) && hasOwn(data, key)) {
         warn(
           `Property ${JSON.stringify(
             key
@@ -524,7 +522,7 @@ export function exposeSetupStateOnRenderContext(
 ) {
   const { ctx, setupState } = instance
   Object.keys(toRaw(setupState)).forEach(key => {
-    if (key[0] === '$' || key[0] === '_') {
+    if (isReservedKey(key)) {
       warn(
         `setup() return property ${JSON.stringify(
           key

From 940af055dfabc454589f5667628bf02bbcd1d06d Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Fri, 19 Feb 2021 20:12:45 +0800
Subject: [PATCH 2/2] chore: improve code

---
 packages/runtime-core/src/componentOptions.ts        | 4 ++--
 packages/runtime-core/src/componentPublicInstance.ts | 9 +++++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/packages/runtime-core/src/componentOptions.ts b/packages/runtime-core/src/componentOptions.ts
index 907ca5ec510..e2a0dbdd02b 100644
--- a/packages/runtime-core/src/componentOptions.ts
+++ b/packages/runtime-core/src/componentOptions.ts
@@ -55,7 +55,7 @@ import { Directive } from './directives'
 import {
   CreateComponentPublicInstance,
   ComponentPublicInstance,
-  isReservedKey
+  isReservedPrefix
 } from './componentPublicInstance'
 import { warn } from './warning'
 import { VNodeChild } from './vnode'
@@ -641,7 +641,7 @@ export function applyOptions(
       for (const key in rawData) {
         checkDuplicateProperties!(OptionTypes.DATA, key)
         // expose data on ctx during dev
-        if (!isReservedKey(key)) {
+        if (!isReservedPrefix(key[0])) {
           Object.defineProperty(ctx, key, {
             configurable: true,
             enumerable: true,
diff --git a/packages/runtime-core/src/componentPublicInstance.ts b/packages/runtime-core/src/componentPublicInstance.ts
index 4cc5bd2cf84..11892abc71d 100644
--- a/packages/runtime-core/src/componentPublicInstance.ts
+++ b/packages/runtime-core/src/componentPublicInstance.ts
@@ -11,7 +11,8 @@ import {
   isGloballyWhitelisted,
   NOOP,
   extend,
-  isString
+  isString,
+  makeMap
 } from '@vue/shared'
 import {
   ReactiveEffect,
@@ -247,7 +248,7 @@ export interface ComponentRenderContext {
   _: ComponentInternalInstance
 }
 
-export const isReservedKey = (key: string) => key[0] === '_' || key[0] === '$'
+export const isReservedPrefix = /*#__PURE__*/ makeMap('_,$')
 
 export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
   get({ _: instance }: ComponentRenderContext, key: string) {
@@ -347,7 +348,7 @@ export const PublicInstanceProxyHandlers: ProxyHandler<any> = {
         // to infinite warning loop
         key.indexOf('__v') !== 0)
     ) {
-      if (data !== EMPTY_OBJ && isReservedKey(key) && hasOwn(data, key)) {
+      if (data !== EMPTY_OBJ && isReservedPrefix(key[0]) && hasOwn(data, key)) {
         warn(
           `Property ${JSON.stringify(
             key
@@ -522,7 +523,7 @@ export function exposeSetupStateOnRenderContext(
 ) {
   const { ctx, setupState } = instance
   Object.keys(toRaw(setupState)).forEach(key => {
-    if (isReservedKey(key)) {
+    if (isReservedPrefix(key[0])) {
       warn(
         `setup() return property ${JSON.stringify(
           key