medium_TokenDataProvider

TokenDataProvider.kt

class TokenDataProvider {
    fun getToken(): Observable<Result<String>> {
        // Just return sample string
        return Observable.just("token")
            .toResult()
    }
}

/**
 * Just an handful extension function which wraps any value or error produced by [Observable] into [Result].
 */
fun <T : Any> Observable<T>.toResult(): Observable<Result<T>> {
    return compose(ObservableToResultTransformer())
}

class ObservableToResultTransformer<T : Any> : ObservableTransformer<T, Result<T>> {
    override fun apply(upstream: Observable<T>): ObservableSource<Result<T>> {
        return upstream.map { Result.success(it) }
            .onErrorReturn { Result.failure(it) }
    }
}