# is-weakset [![Version Badge][2]][1] [![Build Status][3]][4] [![dependency status][5]][6] [![dev dependency status][7]][8] [![License][license-image]][license-url] [![Downloads][downloads-image]][downloads-url] [![npm badge][11]][1] Is this value a JS WeakSet? This module works cross-realm/iframe, and despite ES6 @@toStringTag. ## Example ```js var isWeakSet = require('is-weakset'); assert(!isWeakSet(function () {})); assert(!isWeakSet(null)); assert(!isWeakSet(function* () { yield 42; return Infinity; }); assert(!isWeakSet(Symbol('foo'))); assert(!isWeakSet(1n)); assert(!isWeakSet(Object(1n))); assert(!isWeakSet(new Set())); assert(!isWeakSet(new WeakMap())); assert(!isWeakSet(new Map())); assert(isWeakSet(new WeakSet())); class MyWeakSet extends WeakSet {} assert(isWeakSet(new MyWeakSet())); ``` ## Tests Simply clone the repo, `npm install`, and run `npm test` [1]: https://npmjs.org/package/is-weakset [2]: http://versionbadg.es/inspect-js/is-weakset.svg [3]: https://travis-ci.org/inspect-js/is-weakset.svg [4]: https://travis-ci.org/inspect-js/is-weakset [5]: https://david-dm.org/inspect-js/is-weakset.svg [6]: https://david-dm.org/inspect-js/is-weakset [7]: https://david-dm.org/inspect-js/is-weakset/dev-status.svg [8]: https://david-dm.org/inspect-js/is-weakset#info=devDependencies [11]: https://nodei.co/npm/is-weakset.png?downloads=true&stars=true [license-image]: http://img.shields.io/npm/l/is-weakset.svg [license-url]: LICENSE [downloads-image]: http://img.shields.io/npm/dm/is-weakset.svg [downloads-url]: http://npm-stat.com/charts.html?package=is-weakset