hatch-surf/node_modules/which-collection/README.md
Riley Zhang df378d33ef
Some checks failed
CI / go (push) Waiting to run
CI / docker (push) Waiting to run
CI / lint-go (push) Waiting to run
CI / lint-docs (push) Waiting to run
CI / check-paperclip (push) Waiting to run
Deploy static site / Deploy to GitHub Pages (push) Has been cancelled
Deploy static site / Deploy via Docker to hatch.surf (push) Has been cancelled
Merge GitHub main into Gitea repo (allow unrelated histories)
Resolved conflicts by taking GitHub versions for:
- .dockerignore, .gitignore, Dockerfile, README.md, docker-compose.yml

Kept deploy.sh updated to:
- Pull from GitHub (primary source)
- Push to Gitea (push-mirror)
- Build from site/ directory (GitHub structure)

Co-Authored-By: Paperclip <noreply@paperclip.ing>
2026-06-25 05:20:46 +02:00

2.8 KiB

which-collection Version Badge

github actions coverage dependency status dev dependency status License Downloads

npm badge

Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without instanceof, and despite Symbol.toStringTag.

Example

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