isWeakMap

Checks if a value is a WeakMap instance.

Available since v3.0.0

Import

import { isWeakMap } from '@helpers4/guard';
// or, from the all-in-one package (same code, one install):
import { isWeakMap } from 'helpers4/guard';

isWeakMap(value: unknown): value is WeakMap<object, unknown>

Parameter	Type	Description
`value`	`unknown`	The value to check

value is WeakMap<object, unknown> — True if value is a WeakMap

Distinguishes WeakMap from the regular (iterable) Map.

isWeakMap(new WeakMap()) // => true
isWeakMap(new Map())     // => false

Only real WeakMap instances pass, not objects that merely look like one.

isWeakMap({ get: () => undefined, set: () => {} })
// => false