Sha256: a717ad59c4c930631c0dc207bea045ebd4f4902a19c46f228547ef619ee56177
Contents?: true
Size: 1.58 KB
Versions: 60
Compression:
Stored size: 1.58 KB
Contents
'use strict';
var keys = require('object-keys');
module.exports = function hasSymbols() {
if (typeof Symbol !== 'function' || typeof Object.getOwnPropertySymbols !== 'function') { return false; }
if (typeof Symbol.iterator === 'symbol') { return true; }
var obj = {};
var sym = Symbol('test');
var symObj = Object(sym);
if (typeof sym === 'string') { return false; }
if (Object.prototype.toString.call(sym) !== '[object Symbol]') { return false; }
if (Object.prototype.toString.call(symObj) !== '[object Symbol]') { return false; }
/*
* temp disabled per https://github.com/ljharb/object.assign/issues/17
* if (sym instanceof Symbol) { return false; }
* temp disabled per https://github.com/WebReflection/get-own-property-symbols/issues/4
* if (!(symObj instanceof Symbol)) { return false; }
*/
var symVal = 42;
obj[sym] = symVal;
for (sym in obj) { return false; } // eslint-disable-line no-unreachable-loop
if (keys(obj).length !== 0) { return false; }
if (typeof Object.keys === 'function' && Object.keys(obj).length !== 0) { return false; }
if (typeof Object.getOwnPropertyNames === 'function' && Object.getOwnPropertyNames(obj).length !== 0) { return false; }
var syms = Object.getOwnPropertySymbols(obj);
if (syms.length !== 1 || syms[0] !== sym) { return false; }
if (!Object.prototype.propertyIsEnumerable.call(obj, sym)) { return false; }
if (typeof Object.getOwnPropertyDescriptor === 'function') {
var descriptor = Object.getOwnPropertyDescriptor(obj, sym);
if (descriptor.value !== symVal || descriptor.enumerable !== true) { return false; }
}
return true;
};
Version data entries
60 entries across 59 versions & 5 rubygems