side-channel-weakmap ^{[![Version Badge][npm-version-svg]][package-url]}

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[![License][license-image]][license-url]
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[![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 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