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#coroutines
Title
# coroutines
s

Shashank

10/02/2020, 11:21 AM
How are you testing
StateFlow
? If I have a data class
Copy code
data class ProfileState(val isLoading: Boolean, val userName: String?)
and I have the following states which are being emitted 1. ProfileState(true, null) 2. ProfileState(false, “John Doe”) So how do I that I received the states in the correct order while accounting for the conflation which is done by
StateFlow
?
j

Javier

10/02/2020, 11:24 AM
Have you tried Turbine by Square?
s

Shashank

10/02/2020, 11:30 AM
Nope but I have been using this library to collect all states. However, it fails me in case of conflation as I can receive a single conflated state instead of 2 separate states which I am expecting. This is why I wanted to understand how to test
StateFlow
t

taer

10/02/2020, 3:04 PM
I ahve a similar test case. I kinda hacked my way in w/ a
flow.onStart
that unlocks a pre-locked semaphore. Then I had code that was trying to lock the semaphore. So when the flow test code starts consuming, I know the event capturing is happening. Then I think you could update the MutableState. I didn't use these libs though, I just called flow.toList() in a async job and made my assertions on them.
that way you at least know someone is consuming the flow(and thus possibly helping missing the conflation)
I guess you could use that lib to update the mutableState inside the test method instead. That might be cleaner
s

Shashank

10/02/2020, 3:08 PM
I can’t help but wonder if there is a simpler solution. If we are needing to jump through so many hoops then we might be doing something wrong 🤔
t

taer

10/02/2020, 3:09 PM
Copy code
flow.test(this) {
        assertValues(ProfileState(true, null))
        doTheThingThatChangesTheState()
        assertValues(ProfileState(false, "John Doe"))        
    }
That feels better to me(if you only have one flow)
At least in my case, I needed the collectors to run in a different coroutine so I could tweak their inputs in the main test thread.
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