isOk - API reference

API reference › @evolu/common › Result › isOk

function isOk<T, E>(result: Result<T, E>): result is Ok<T>;

Defined in: packages/common/src/Result.ts:376

Type guard for Ok results.

Example

import {
  assertEqual,
  assertType,
  isOk,
  ok,
  type Ok,
  type Result,
  type Typed,
} from "@evolu/common";

const getCount = (): Result<number, CountUnavailableError> => ok(2);

interface CountUnavailableError extends Typed<"CountUnavailable"> {}

const count = getCount();
if (isOk(count)) {
  assertType<Ok<number>, typeof count>();
  assertEqual(count.value, 2);
}