RxSwift Observable Retry When with Count

RxSwift_Observable_RetryCountWhen.swift

extension ObservableType {
    func retry(_ maxAttemptCount: Int = 1, when: @escaping (Error) -> Observable<Void>) -> Observable<E> {
        return retryWhen { errorObservable -> Observable<Void> in
            var retries = maxAttemptCount
            return errorObservable.flatMap { error -> Observable<Void> in
                guard retries > 0 else { return Observable.error(error) }
                retries -= 1
                return when(error)
            }
        }
    }
}

// Example usage:

func fetchSomething() -> Observable<String> { ... }

fetchSomething()
    .retry(2, when: { error -> Observable<Void> in
        print("^^^ RETRYING AFTER ERROR: \(error)")
        return Observable.just(()) // just retry
    })
    .subscribe(
        onNext: { print("^^^ NEXT: \($0)") },
        onError: { print("^^^ ERROR: \($0)" )},
        onCompleted: { print("^^^ COMPLETED") },
        onDisposed: { print("^^^ DISPOSED") }
    )
    .disposed(by: disposeBag)