https://github.com/webreflection/not-so-weak

Iterable WeakMap, WeakSet and WeakValue
https://github.com/webreflection/not-so-weak

Last synced: over 1 year ago
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Iterable WeakMap, WeakSet and WeakValue

• Host: GitHub
• URL: https://github.com/webreflection/not-so-weak
• Owner: WebReflection
• License: isc
• Created: 2023-01-26T09:54:54.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2023-07-14T13:52:47.000Z (about 3 years ago)
• Last Synced: 2025-03-27T14:11:17.155Z (over 1 year ago)
• Language: JavaScript
• Homepage:
• Size: 53.7 KB
• Stars: 37
• Watchers: 2
• Forks: 1
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# Not So Weak

[![build status](https://github.com/WebReflection/not-so-weak/actions/workflows/node.js.yml/badge.svg)](https://github.com/WebReflection/not-so-weak/actions) [![Coverage Status](https://coveralls.io/repos/github/WebReflection/not-so-weak/badge.svg?branch=main)](https://coveralls.io/github/WebReflection/not-so-weak?branch=main)

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Iterable [WeakMap](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap) (*WKey*) and [WeakSet](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakSet) (*WSet*) through [FinalizationRegistry](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry) and [WeakRef](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakRef) primitives, reimplementing also the [WeakValue](https://github.com/WebReflection/weak-value#readme) (*WValue*) module, including the optional *callback* for collected values.

```js

// const {WSet, WKey, WValue} = require('not-so-weak');

import {WSet, WKey, WValue} from 'not-so-weak';

// class WSet extends WeakSet implements Set {}

// class WKey extends WeakMap implements Map {}

// class WValue extends Map {}

// node --expose-gc example

const ws = new WSet([{}]);

const wm = new WKey([[{}, 'value']]);

const wv = new WValue;

wv.set('value', {}, function (key) {

  console.assert(this === wv);

  console.assert(key === 'value');

  console.log(key, 'value collected');

});

console.assert(ws.size === 1);

console.assert(wm.size === 1);

console.assert([...wm.values()][0] === 'value');

console.assert([...wv.keys()][0] === 'value');

setTimeout(() => {

  gc();

  console.assert(ws.size === 0);

  console.assert(wm.size === 0);

  console.assert(wv.size === 0);

});

```

### Suitable For

  * Weak key/value based state/store

  * Server Side related tasks that can't bother with manual removal of weakly referenced entries

  * every case where you end up swapping to `Map` or `Set` because you realize you cannot iterate over their *Weak* counterpart

  * every case where you think there's a memory leak due possibly missing `weakThing.delete(ref)` operations

### Not Suitable For

  * raw performance or benchmarks against `Map` or `Set`

  * every case where `weakThing.delete(ref)` is already handled by the library or framework logic