# side-channel-weakmap

> Store information about any JS value in a side channel. Uses WeakMap if available.

Latest version **1.0.2** (published 2024-12-11) · MIT license · 0 weekly downloads

## Install

```sh
npm install side-channel-weakmap
pnpm add side-channel-weakmap
yarn add side-channel-weakmap
bun add side-channel-weakmap
```

## Health

**Score 50/100 (C)** — status: stable.

Positive: has types; esm support; no vulnerabilities; high quality score.

Warnings: low downloads.

Negative: stale.

## Facts

| | |
|---|---|
| Version | 1.0.2 |
| Published | 2024-12-11 |
| First published | 2024-12-10 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Node | >= 0.4 |
| Dependencies | 5 |
| Unpacked size | 14.3 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 0 |
| Author | Jordan Harband |
| Maintainers | ljharb |
| Keywords | weakmap, map, side, channel, metadata |

## Links

- npm: https://www.npmjs.com/package/side-channel-weakmap
- Repository: https://github.com/ljharb/side-channel-weakmap
- Homepage: https://github.com/ljharb/side-channel-weakmap#readme
- Issues: https://github.com/ljharb/side-channel-weakmap/issues
- Funding: https://github.com/sponsors/ljharb
- npm.io page: https://npm.io/package/side-channel-weakmap

## Dependencies (5)

- [es-errors](https://npm.io/package/es-errors.md) ^1.3.0
- [call-bound](https://npm.io/package/call-bound.md) ^1.0.2
- [get-intrinsic](https://npm.io/package/get-intrinsic.md) ^1.2.5
- [object-inspect](https://npm.io/package/object-inspect.md) ^1.13.3
- [side-channel-map](https://npm.io/package/side-channel-map.md) ^1.0.1

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## Recent versions

- 1.0.2 (latest) — 2024-12-11
- 1.0.1 — 2024-12-11
- 1.0.0 — 2024-12-10

## README

# side-channel-weakmap <sup>[![Version Badge][npm-version-svg]][package-url]</sup>

[![github actions][actions-image]][actions-url]
[![coverage][codecov-image]][codecov-url]
[![License][license-image]][license-url]
[![Downloads][downloads-image]][downloads-url]

[![npm badge][npm-badge-png]][package-url]

Store information about any JS value in a side channel. Uses WeakMap if available.

Warning: this implementation will leak memory until you `delete` the `key`.
Use [`side-channel`](https://npmjs.com/side-channel) for the best available strategy.

## Getting started

```sh
npm install --save side-channel-weakmap
```

## Usage/Examples

```js
const assert = require('assert');
const getSideChannelList = require('side-channel-weakmap');

const channel = getSideChannelList();

const key = {};
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);

channel.set(key, 42);

channel.assert(key); // does not throw
assert.equal(channel.has(key), true);
assert.equal(channel.get(key), 42);

channel.delete(key);
assert.equal(channel.has(key), false);
assert.throws(() => channel.assert(key), TypeError);
```

## Tests

Clone the repo, `npm install`, and run `npm test`

[package-url]: https://npmjs.org/package/side-channel-weakmap
[npm-version-svg]: https://versionbadg.es/ljharb/side-channel-weakmap.svg
[deps-svg]: https://david-dm.org/ljharb/side-channel-weakmap.svg
[deps-url]: https://david-dm.org/ljharb/side-channel-weakmap
[dev-deps-svg]: https://david-dm.org/ljharb/side-channel-weakmap/dev-status.svg
[dev-deps-url]: https://david-dm.org/ljharb/side-channel-weakmap#info=devDependencies
[npm-badge-png]: https://nodei.co/npm/side-channel-weakmap.png?downloads=true&stars=true
[license-image]: https://img.shields.io/npm/l/side-channel-weakmap.svg
[license-url]: LICENSE
[downloads-image]: https://img.shields.io/npm/dm/side-channel-weakmap.svg
[downloads-url]: https://npm-stat.com/charts.html?package=side-channel-weakmap
[codecov-image]: https://codecov.io/gh/ljharb/side-channel-weakmap/branch/main/graphs/badge.svg
[codecov-url]: https://app.codecov.io/gh/ljharb/side-channel-weakmap/
[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/ljharb/side-channel-weakmap
[actions-url]: https://github.com/ljharb/side-channel-weakmap/actions

---
_Source: https://npm.io/package/side-channel-weakmap · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._