I want to create a library with a custom time-based operator extension on Flow, such as for example

Flow<T>.throttleFirst()

here. @elizarov wrote that to test such an operator we would have to use the

DelayController

if available instead of

System.currentTimeMills()

, which of course makes total sense. My question: How could I publish this library without having

kotlinx-coroutines-test

in the release dependencies? Meaning how would I prevent the user of my library having

kotlinx-coroutines-test

in their release binaries when they use my dependency?

You can just use

TimeSource.Monotonic

and

delay

(experimental time API). Then, if users use delay controlling dispatcher, it will just work, without you having to do anything special.

Thanks! That would mean I would require the library user to use an experimental api, which is fine for my use-case. But is there a way that this could be implemented without this experimental API and not publishing it with test dependencies in release?

@flosch Yes, you can use

System.nanoTime()

yourself (on JVM/ART, other platforms have different APIs), and count milliseconds after converting from nanos, or count it all in nanoseconds.

Sure, yes, that is what I am currently doing! However this does not let me use the

DelayController

, when testing my custom operator. Or am I missing something?

You can use

delay

which is controlled by

DelayController

in test conditions.

Ahh okay, yea that actually makes sense! Thank you very much