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43 lines
1.2 KiB
43 lines
1.2 KiB
'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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