optional

optional<T, O>(arbitrary, constraints): Nothing extends O ? Dependent<Maybe<T>> : Dependent<O | T>

optional takes an arbitrary and returns an arbitrary that is either the original arbitrary or the optional symbol

Example

random(optional(integer()))
// => Nothing

random(optional(integer()))
// => 1234

random(optional(integer({symbol: undefined})))
// => undefined

Type Parameters

• T

• O = typeof Nothing

Parameters

arbitrary

Arbitrary<T>

The arbitrary to make optional.

constraints

MaybePartial<OptionalGenerator<O>> = {}

The constraints used to generate arbitrary values.

Returns

Nothing extends O ? Dependent<Maybe<T>> : Dependent<O | T>

An optional version of the given arbitrary.