RxJava+Kotlinでログを吐かせる便利拡張関数

fun <T> Observable<T>.logging(tag: String = Throwable().stackTrace[1].methodName): Observable<T> = this
    .doOnSubscribe {
        Log.d(tag, "doOnSubscribe")
    }
    .doOnNext {
        Log.d(tag, "doOnNext = $it")
    }
    .doOnError {
        Log.d(tag, "doOnError = $it")
    }
    .doOnComplete {
        Log.d(tag, "doOnComplete")
    }
    .doOnDispose {
        Log.d(tag, "doOnDispose")
    }

使うとき

rxObject
  .map { /* something to do */ }
  .logging("rxObject")
  .subscribeBy { /* something to do */ }

みたいにすれば、ログが吐かれる