mapOrElse

function ResultAsync.mapOrElse(
    result: AwaitableResult<T, E>,
    transform: (value: T) => U | Promise<U>,
    orElse: (error: E) => F | Promise<F>
): Promise<U | F>

Unwraps the Ok value using the transform function, or transforms the Err value using the orElse function.

Example

data-first

await ResultAsync.mapOrElse(
    ok(5),
    (x) => x * 2,
    (e) => `Error: ${e}`,
);
// 10

await ResultAsync.mapOrElse(
    err("fail"),
    (x) => x * 2,
    (e) => `Error: ${e}`,
);
// "Error: fail"

data-last

await pipe(
    ok(5),
    ResultAsync.mapOrElse(
        (x) => x * 2,
        (e) => `Error: ${e}`,
    ),
);
// 10