21 lines
548 B
JavaScript
21 lines
548 B
JavaScript
"use strict";
|
|
|
|
var global = require("ext/global-this")
|
|
, validTypes = { object: true, symbol: true };
|
|
|
|
module.exports = function () {
|
|
var Symbol = global.Symbol;
|
|
var symbol;
|
|
if (typeof Symbol !== "function") return false;
|
|
symbol = Symbol("test symbol");
|
|
try { String(symbol); }
|
|
catch (e) { return false; }
|
|
|
|
// Return 'true' also for polyfills
|
|
if (!validTypes[typeof Symbol.iterator]) return false;
|
|
if (!validTypes[typeof Symbol.toPrimitive]) return false;
|
|
if (!validTypes[typeof Symbol.toStringTag]) return false;
|
|
|
|
return true;
|
|
};
|