retrywhen.js

Rx.Observable.create(o => {
      console.log("subscribing");
      o.onError(new Error("always fails"));
  }).retryWhen(attempts -> {
      return attempts.zip(Rx.Observable.range(1, 3), (n, i) => i).flatMap(i => {
          console.log("delay retry by " + i + " second(s)");
          return Rx.Observable.timer(i * 1000);
      });
  }).subscribe();
  
  /*
subscribing
delay retry by 1 second(s)
subscribing
delay retry by 2 second(s)
subscribing
delay retry by 3 second(s)
subscribing
*/