From 4fd2ce813cd0a59bd544defe07f44a5731e45f84 Mon Sep 17 00:00:00 2001
From: Derek Kent <derek.a.kent@gmail.com>
Date: Thu, 28 Sep 2017 10:53:40 -0400
Subject: [PATCH] fix: allow an object's Symbols to be observed (#6704)

Attempting to parseFloat on a Symbol throws the error
`Cannot convert a Symbol value to a string`.

A Symbol can be cast to a string using `.toString()` or `String()` though,
so explicitly casting before parsing resolves the issue, allowing `Vue.set` to
be called on Symbols.
---
 src/shared/util.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/shared/util.js b/src/shared/util.js
index 709fe14640..b6b3eb5dcb 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -56,7 +56,7 @@ export function isRegExp (v: any): boolean {
  * Check if val is a valid array index.
  */
 export function isValidArrayIndex (val: any): boolean {
-  const n = parseFloat(val)
+  const n = parseFloat(String(val))
   return n >= 0 && Math.floor(n) === n && isFinite(val)
 }