From 0bdee72e17f920354c4e72a921b944e22bf30ad9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=89=A9=E6=95=A3=E6=80=A7=E7=99=BE=E4=B8=87=E7=94=9C?=
 =?UTF-8?q?=E9=9D=A2=E5=8C=85?= <himself65@outlook.com>
Date: Sun, 6 Oct 2019 03:46:36 +0800
Subject: [PATCH] feat(reactivity): use Symbol for Ref._isRef (#114)

---
 packages/reactivity/src/computed.ts |  4 ++--
 packages/reactivity/src/ref.ts      | 10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/packages/reactivity/src/computed.ts b/packages/reactivity/src/computed.ts
index f06eb0a8..9ed42716 100644
--- a/packages/reactivity/src/computed.ts
+++ b/packages/reactivity/src/computed.ts
@@ -1,5 +1,5 @@
 import { effect, ReactiveEffect, activeReactiveEffectStack } from './effect'
-import { Ref, UnwrapNestedRefs } from './ref'
+import { Ref, refSymbol, UnwrapNestedRefs } from './ref'
 import { isFunction } from '@vue/shared'
 
 export interface ComputedRef<T> extends Ref<T> {
@@ -43,7 +43,7 @@ export function computed<T>(
     }
   })
   return {
-    _isRef: true,
+    _isRef: refSymbol,
     // expose effect so computed can be stopped
     effect: runner,
     get value() {
diff --git a/packages/reactivity/src/ref.ts b/packages/reactivity/src/ref.ts
index c3fc1c02..ad39a74f 100644
--- a/packages/reactivity/src/ref.ts
+++ b/packages/reactivity/src/ref.ts
@@ -3,8 +3,10 @@ import { OperationTypes } from './operations'
 import { isObject } from '@vue/shared'
 import { reactive } from './reactive'
 
+export const refSymbol = Symbol()
+
 export interface Ref<T> {
-  _isRef: true
+  _isRef: symbol
   value: UnwrapNestedRefs<T>
 }
 
@@ -15,7 +17,7 @@ const convert = (val: any): any => (isObject(val) ? reactive(val) : val)
 export function ref<T>(raw: T): Ref<T> {
   raw = convert(raw)
   const v = {
-    _isRef: true,
+    _isRef: refSymbol,
     get value() {
       track(v, OperationTypes.GET, '')
       return raw
@@ -29,7 +31,7 @@ export function ref<T>(raw: T): Ref<T> {
 }
 
 export function isRef(v: any): v is Ref<any> {
-  return v ? v._isRef === true : false
+  return v ? v._isRef === refSymbol : false
 }
 
 export function toRefs<T extends object>(
@@ -47,7 +49,7 @@ function toProxyRef<T extends object, K extends keyof T>(
   key: K
 ): Ref<T[K]> {
   const v = {
-    _isRef: true,
+    _isRef: refSymbol,
     get value() {
       return object[key]
     },