internal-slot (1.1.0)
Published 2026-02-24 13:58:11 +00:00 by atheaadmin
Installation
registry=npm install internal-slot@1.1.0"internal-slot": "1.1.0"About this package
internal-slot 
Truly private storage, akin to the JS spec’s concept of internal slots.
Uses a WeakMap when available; a Map when not; and a regular object in even older engines. Performance and garbage collection behavior will reflect the environment’s capabilities accordingly.
Example
var SLOT = require('internal-slot');
var assert = require('assert');
var o = {};
assert.throws(function () { SLOT.assert(o, 'foo'); });
assert.equal(SLOT.has(o, 'foo'), false);
assert.equal(SLOT.get(o, 'foo'), undefined);
SLOT.set(o, 'foo', 42);
assert.equal(SLOT.has(o, 'foo'), true);
assert.equal(SLOT.get(o, 'foo'), 42);
assert.doesNotThrow(function () { SLOT.assert(o, 'foo'); });
Tests
Simply clone the repo, npm install, and run npm test
Security
Please email @ljharb or see https://tidelift.com/security if you have a potential security vulnerability to report.
Dependencies
Dependencies
| ID | Version |
|---|---|
| es-errors | ^1.3.0 |
| hasown | ^2.0.2 |
| side-channel | ^1.1.0 |
Development Dependencies
| ID | Version |
|---|---|
| @arethetypeswrong/cli | ^0.17.1 |
| @ljharb/eslint-config | ^21.1.1 |
| @ljharb/tsconfig | ^0.2.2 |
| @types/for-each | ^0.3.3 |
| @types/object-inspect | ^1.13.0 |
| @types/tape | ^5.6.5 |
| auto-changelog | ^2.5.0 |
| encoding | ^0.1.13 |
| eslint | =8.8.0 |
| for-each | ^0.3.3 |
| in-publish | ^2.0.1 |
| npmignore | ^0.3.1 |
| nyc | ^10.3.2 |
| object-inspect | ^1.13.3 |
| safe-publish-latest | ^2.0.0 |
| tape | ^5.9.0 |
| typescript | next |
Keywords
internal
slot
internal slot
ecmascript
es
spec
private
data
private data
weakmap