From bacb911f7df09ff4868b4c848a6d7778872dff5c Mon Sep 17 00:00:00 2001
From: Herrington Darkholme <HerringtonDarkholme@users.noreply.github.com>
Date: Tue, 19 Dec 2017 22:35:50 +0800
Subject: [PATCH] fix(warning): allow symbol as vdom key (#7271)

---
 src/core/vdom/patch.js                        | 2 +-
 src/shared/util.js                            | 2 ++
 test/unit/modules/vdom/create-element.spec.js | 9 +++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/core/vdom/patch.js b/src/core/vdom/patch.js
index b5296db3c..00c67a5b1 100644
--- a/src/core/vdom/patch.js
+++ b/src/core/vdom/patch.js
@@ -270,7 +270,7 @@ export function createPatchFunction (backend) {
         createElm(children[i], insertedVnodeQueue, vnode.elm, null, true)
       }
     } else if (isPrimitive(vnode.text)) {
-      nodeOps.appendChild(vnode.elm, nodeOps.createTextNode(vnode.text))
+      nodeOps.appendChild(vnode.elm, nodeOps.createTextNode(String(vnode.text)))
     }
   }
 
diff --git a/src/shared/util.js b/src/shared/util.js
index fe1c025e4..a0bc957ee 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -27,6 +27,8 @@ export function isPrimitive (value: any): boolean %checks {
   return (
     typeof value === 'string' ||
     typeof value === 'number' ||
+    // $flow-disable-line
+    typeof value === 'symbol' ||
     typeof value === 'boolean'
   )
 }
diff --git a/test/unit/modules/vdom/create-element.spec.js b/test/unit/modules/vdom/create-element.spec.js
index 3bec065f3..f2fddcf6d 100644
--- a/test/unit/modules/vdom/create-element.spec.js
+++ b/test/unit/modules/vdom/create-element.spec.js
@@ -215,6 +215,15 @@ describe('create-element', () => {
     expect('Avoid using non-primitive value as key').not.toHaveBeenWarned()
   })
 
+  it('doesn\'t warn symbol key', () => {
+    new Vue({
+      render (h) {
+        return h('div', { key: Symbol('symbol') })
+      }
+    }).$mount()
+    expect('Avoid using non-primitive value as key').not.toHaveBeenWarned()
+  })
+
   it('nested child elements should be updated correctly', done => {
     const vm = new Vue({
       data: { n: 1 },