validateWeakSet

Validates that a value is a WeakSet instance. This helper uses the isWeakSet type guard internally. Only native WeakSet instances and wrapper objects created with Object(...) pass this check.

It never throws and never mutates input. Use it when you need to validate object‑keyed sets before applying further structural or element‑level validation.

Signature

function validateWeakSet(
  value: unknown,
  field: string
): ValidationResult<WeakSet<object>>

Parameters

Name	Data type	Description
value	unknown	The value to validate.
field	string	The name of the field being validated, used in error reporting.

Returns

One of:

• { ok: true, value: WeakSet }: If value is a WeakSet.
• { ok: false, field: string, message: string }: If value is not a WeakSet.

Behavior

• Uses isWeakSet internally.
• Accepts:
• new WeakSet().
• new WeakSet([object]).
• Object(new WeakSet()).
• Subclasses of WeakSet.
• Rejects:
• Set, Map, WeakMap.
• plain objects.
• Arrays and primitives.
• Never throws or mutates input.

Examples

const key = {};
validateWeakSet(new WeakSet([key]), "cache")
// { ok: true, value: WeakSet { [object Object] } }

validateWeakSet({}, "obj")
// { ok: false, field: "obj", message: "Value must be a WeakSet" }

Notes

• This validator checks only that the value is a WeakSet. It does not validate element types. For that, use higher‑level helpers.