isOption

@ts-rust/std

---

@ts-rust/std / Option / isOption

Function: isOption()

function isOption(x): x is Option<unknown>;

Defined in: packages/std/src/option/option.ts:175

Checks if a value is an Option, narrowing its type to Option<unknown>.

This type guard verifies whether the input conforms to the Optional interface, indicating it is either a Some or None.

Parameters

Parameter	Type	Description
x	unknown	The value to check.

Returns

x is Option<unknown>

true if the value is an Option, narrowing to Option<unknown>.

Example

const x: unknown = some(42);
const y: unknown = none<number>();
const z: unknown = "not an option";

expect(isOption(x)).toBe(true);
expect(isOption(y)).toBe(true);
expect(isOption(z)).toBe(false);

if (isOption(x)) {
  expect(x.isSome()).toBe(true); // Type narrowed to Option<unknown>
}