I have 2 flows, one of them is cold, another is hot. The goal is to

merge

them, and collect all values they produce(and complete them all when the resulting flow completes). Issue: no items emitted, when hot one is idle. What is the nice way to combine two flows, making the resulting one - cold? where: • banEvents: MutableStateFlow • chatMessagesOutput: Flow

What do you mean merge them? • pair them together (one emission everytime both of them emit): https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/zip.html • all values one after the other (unknown order): https://kotlinlang.org/api/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.corout[…]%20%3CT%3E%20Iterable%3CFlow%3CT%3E%3E.merge():%20Flow%3CT%3E

I mean all values from both without any order

Then you can use the second link

I've tried that out at first place, but my Turbine tests fails after using that operator. Says "no values produced in 10s"(our timeout for flow testing)

You can add

.onEach { println("some message: $it") }

to both of your flows (before the merge) to check that they do emit values

onEach

prints whatever goes through the flow without impacting it

Yes, Ivan, that's the point, the StateFlow emits nothing in this particular case

From the screen shot, is

chatMessages

the

StateFlow

?

@Kevin Worth no, it is cold

Flow

banEvents

, then?

yes

And

filterNotNull().onEach { println(it) }

prints nothing? Are you sure there’s an

emit

somewhere on

banEvents

?

Seems like I'm missing something

I think it would help to see more of the code, to try to get to an answer.

OK, guys, seems like the resulting flow (after

merge

) just never completes, that's why I'm catching the error in Turbine test(yes, I still receive chat messages, no bans since they are null)