44 lines
1.2 KiB
JavaScript
44 lines
1.2 KiB
JavaScript
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'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var callBound = require('call-bound');
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var $WeakSet = GetIntrinsic('%WeakSet%', true);
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/** @type {undefined | (<V>(thisArg: Set<V>, value: V) => boolean)} */
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var $setHas = callBound('WeakSet.prototype.has', true);
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if ($setHas) {
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/** @type {undefined | (<K extends object, V>(thisArg: WeakMap<K, V>, key: K) => boolean)} */
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var $mapHas = callBound('WeakMap.prototype.has', true);
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/** @type {import('.')} */
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module.exports = function isWeakSet(x) {
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if (!x || typeof x !== 'object') {
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return false;
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}
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try {
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// @ts-expect-error TS can't figure out that $setHas is always truthy here
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$setHas(x, $setHas);
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if ($mapHas) {
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try {
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// @ts-expect-error this indeed might not be a weak collection
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$mapHas(x, $mapHas);
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} catch (e) {
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return true;
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}
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}
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// @ts-expect-error TS can't figure out that $WeakSet is always truthy here
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return x instanceof $WeakSet; // core-js workaround, pre-v3
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} catch (e) {}
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return false;
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};
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} else {
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/** @type {import('.')} */
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// @ts-expect-error
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module.exports = function isWeakSet(x) { // eslint-disable-line no-unused-vars
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// `WeakSet` does not exist, or does not have a `has` method
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return false;
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};
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}
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