| # which-collection <sup>[![Version Badge][2]][1]</sup> |
| |
| [![github actions][actions-image]][actions-url] |
| [![coverage][codecov-image]][codecov-url] |
| [![dependency status][5]][6] |
| [![dev dependency status][7]][8] |
| [![License][license-image]][license-url] |
| [![Downloads][downloads-image]][downloads-url] |
| |
| [![npm badge][11]][1] |
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| Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag. |
| |
| ## Example |
| |
| ```js |
| var whichCollection = require('which-collection'); |
| var assert = require('assert'); |
| |
| assert.equal(false, whichCollection(undefined)); |
| assert.equal(false, whichCollection(null)); |
| assert.equal(false, whichCollection(false)); |
| assert.equal(false, whichCollection(true)); |
| assert.equal(false, whichCollection([])); |
| assert.equal(false, whichCollection({})); |
| assert.equal(false, whichCollection(/a/g)); |
| assert.equal(false, whichCollection(new RegExp('a', 'g'))); |
| assert.equal(false, whichCollection(new Date())); |
| assert.equal(false, whichCollection(42)); |
| assert.equal(false, whichCollection(NaN)); |
| assert.equal(false, whichCollection(Infinity)); |
| assert.equal(false, whichCollection(new Number(42))); |
| assert.equal(false, whichCollection(42n)); |
| assert.equal(false, whichCollection(Object(42n))); |
| assert.equal(false, whichCollection('foo')); |
| assert.equal(false, whichCollection(Object('foo'))); |
| assert.equal(false, whichCollection(function () {})); |
| assert.equal(false, whichCollection(function* () {})); |
| assert.equal(false, whichCollection(x => x * x)); |
| assert.equal(false, whichCollection([])); |
| |
| assert.equal('Map', whichCollection(new Map())); |
| assert.equal('Set', whichCollection(new Set())); |
| assert.equal('WeakMap', whichCollection(new WeakMap())); |
| assert.equal('WeakSet', whichCollection(new WeakSet())); |
| ``` |
| |
| ## Tests |
| Simply clone the repo, `npm install`, and run `npm test` |
| |
| [1]: https://npmjs.org/package/which-collection |
| [2]: https://versionbadg.es/inspect-js/which-collection.svg |
| [5]: https://david-dm.org/inspect-js/which-collection.svg |
| [6]: https://david-dm.org/inspect-js/which-collection |
| [7]: https://david-dm.org/inspect-js/which-collection/dev-status.svg |
| [8]: https://david-dm.org/inspect-js/which-collection#info=devDependencies |
| [11]: https://nodei.co/npm/which-collection.png?downloads=true&stars=true |
| [license-image]: https://img.shields.io/npm/l/which-collection.svg |
| [license-url]: LICENSE |
| [downloads-image]: https://img.shields.io/npm/dm/which-collection.svg |
| [downloads-url]: https://npm-stat.com/charts.html?package=which-collection |
| [codecov-image]: https://codecov.io/gh/inspect-js/which-collection/branch/main/graphs/badge.svg |
| [codecov-url]: https://app.codecov.io/gh/inspect-js/which-collection/ |
| [actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/inspect-js/which-collection |
| [actions-url]: https://github.com/inspect-js/which-collection/actions |