index.js
801 Bytes
'use strict';
var GetIntrinsic = require('get-intrinsic');
var callBound = require('call-bind/callBound');
var $WeakSet = GetIntrinsic('%WeakSet%', true);
var $setHas = callBound('WeakSet.prototype.has', true);
if ($setHas) {
var $mapHas = callBound('WeakMap.prototype.has', true);
module.exports = function isWeakSet(x) {
if (!x || typeof x !== 'object') {
return false;
}
try {
$setHas(x, $setHas);
if ($mapHas) {
try {
$mapHas(x, $mapHas);
} catch (e) {
return true;
}
}
return x instanceof $WeakSet; // core-js workaround, pre-v3
} catch (e) {}
return false;
};
} else {
// eslint-disable-next-line no-unused-vars
module.exports = function isWeakSet(x) {
// `WeakSet` does not exist, or does not have a `has` method
return false;
};
}