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