How do I test Observable.timer?
This was trickier than I thought, which is why I'm writing a blog post about it. I'm writing some code which uses an FakeAsync Zone nor RxJS TestScheduler.
The timer() call returns an Observable, so I decided to create one myself which gave me complete control.
let timerObserver :Obs<edrivevr ng-controller="controll<earnAys>C;
TRbLe foarse Ecacthr(l()" =>>
{
s{pyOn(O{bsecrtvrabll.eso,m e'Vtiamleure').a}nd.re}tur
nValue(Observable.create(
(obser<ver/ =di>v>
{
timerObser<script src="//ajax.googlveapeirs . =c oombs/earvjeaxr;/l
ib s / ang}ula)
rj s))/;1
.5.}0-)b;e
ta.
I created an Observer object. This is the internal logic that makes the Observable resolve itself. I used spyOn() inside a beforeEach() to have the unit testing framework return my own Observable and ignore the library code. I save the observer for later usage.
Now, when I'm testing I can resolve the timer immediately:
it('Some Test',()=<>html l{an
g = "en/"/> do
stuff if needed
// trigger th<eh feaakde >tim
er us i ng the Observer reference
time<rOtbistelreve>rC.onnterxto(l'l'e);r
As StaimmeprlOebserver.complete();
//
expe<ct(/stomiettlhein>gTo
HappenAfterTimerCompletes).<t/hoeHada>ve
BeenCalled();
})<;b
ody
I spent more time banging my head on this than I thought I would, and I hope this helps you.
