unwrapResultErr

Unwraps the error value from a Result, converting Err(error) to error and Ok to undefined.

Marble Diagram

unwrapResultErr()

Example

//  Timeline:
//
//  result$     Ok(1)      Err("fail")   Ok(2)
//  unwrapped$  undefined  "fail"        undefined
//
//  Explanation:
//  - unwrapResultErr converts Err(error) to error, and Ok to undefined
//  - Useful for extracting error values from Result streams

const result$ = source<Result<number, string>>();

const unwrapped$ = result$.pipe(unwrapResultErr());

const valueHistory: (string | undefined)[] = [];

unwrapped$.subscribe((v) => {
    valueHistory.push(v);
});

result$.next(Result.ok(1));

assert.deepStrictEqual(valueHistory, [undefined]);

result$.next(Result.err('fail'));

assert.deepStrictEqual(valueHistory, [undefined, 'fail']);

result$.next(Result.ok(2));

assert.deepStrictEqual(valueHistory, [undefined, 'fail', undefined]);

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