is-finalizationregistry Version Badge

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Is this value a JS FinalizationRegistry? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Example

```js var isFinalizationRegistry = require('is-finalizationregistry'); assert(!isFinalizationRegistry(function () {})); assert(!isFinalizationRegistry(null)); assert(!isFinalizationRegistry(function* () { yield 42; return Infinity; }); assert(!isFinalizationRegistry(Symbol('foo'))); assert(!isFinalizationRegistry(1n)); assert(!isFinalizationRegistry(Object(1n)));

assert(!isFinalizationRegistry(new Set())); assert(!isFinalizationRegistry(new WeakSet())); assert(!isFinalizationRegistry(new Map())); assert(!isFinalizationRegistry(new WeakMap())); assert(!isFinalizationRegistry(new WeakRef({})));

assert(isFinalizationRegistry(new FinalizationRegistry(function () {})));

class MyFinalizationRegistry extends FinalizationRegistry {} assert(isFinalizationRegistry(new MyFinalizationRegistry(function () {}))); ```

Tests

Simply clone the repo, npm install, and run npm test