Unsubscribe from takeLast

[samuelgruetter]

When I unsubscribe from an Observable which emits the last value of an infinite stream, I expect to get no element. This is the case in C#:

var o = Observable.Interval(TimeSpan.FromMilliseconds(200)).TakeLast(1);
var s = o.Subscribe(i => Console.WriteLine("Interesting: Infinity = " + i));
Thread.Sleep(1000);
s.Dispose();
Thread.Sleep(1000);
Console.WriteLine("Press any key...");
Console.ReadKey();

outputs

Press any key...

But with RxJava, it's different (note that Scala's takeRight calls Java's takeLast):

val o = Observable.interval(200 millis).takeRight(1)
val s = o.subscribe(i => println(s"Interesting: Infinity = $i"))
Thread.sleep(1000)
s.unsubscribe()
Thread.sleep(1000)  

outputs

Interesting: Infinity = 4

[zsxwing]

It's an issue of interval. Here is the unit test to reveal it:

    @Test
    public void testIssue521() throws InterruptedException {
        Observable<Long> o = Observable.interval(200, TimeUnit.MILLISECONDS);
        Subscription s = o.subscribe(new Observer<Long>() {

            @Override
            public void onCompleted() {
                System.out.println("onCompleted");
            }

            @Override
            public void onError(Throwable e) {
            }

            @Override
            public void onNext(Long args) {
                System.out.println(args);
            }
        });
        Thread.sleep(1000);
        s.unsubscribe();
    }

Output:

1
2
3
4
onCompleted

I think unsubscribe should not call onCompleted.

[zsxwing]

Here is the case in Rx.Net:

            var o = Observable.Interval(TimeSpan.FromMilliseconds(200));
            var s = o.Subscribe(
                i => Console.WriteLine("Interesting: Infinity = " + i),
                e =>  Console.WriteLine(e),
                () => Console.WriteLine("onCompleted")
                );
            Thread.Sleep(1000);
            s.Dispose();
            Console.WriteLine("Press any key...");
            Console.ReadKey();

Output is:

Interesting: Infinity = 0
Interesting: Infinity = 1
Interesting: Infinity = 2
Interesting: Infinity = 3
Press any key...

[benjchristensen]

Fixed in #522