https://github.com/inspect-js/which-collection

Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.
https://github.com/inspect-js/which-collection

collection javascript map set weakmap weakset which

Last synced: 3 months ago
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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.

• Host: GitHub
• URL: https://github.com/inspect-js/which-collection
• Owner: inspect-js
• License: mit
• Created: 2019-11-13T07:47:13.000Z (almost 5 years ago)
• Default Branch: main
• Last Pushed: 2024-03-10T22:08:01.000Z (8 months ago)
• Last Synced: 2024-07-18T05:40:46.708Z (4 months ago)
• Topics: collection, javascript, map, set, weakmap, weakset, which
• Language: JavaScript
• Homepage:
• Size: 64.5 KB
• Stars: 10
• Watchers: 4
• Forks: 2
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# which-collection [![Version Badge][2]][1]

[![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]

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