setup-php/node_modules/has-symbols/index.js

'use strict';

var origSymbol = global.Symbol;
var hasSymbolSham = require('./shams');

module.exports = function hasNativeSymbols() {
	if (typeof origSymbol !== 'function') { return false; }
	if (typeof Symbol !== 'function') { return false; }
	if (typeof origSymbol('foo') !== 'symbol') { return false; }
	if (typeof Symbol('bar') !== 'symbol') { return false; }

	return hasSymbolSham();
};