A modern programming language that makes developers happier.

kotlinlang

Hi all, how do you guys test a StateFlow in Android, for example, a ViewModel?

with LiveData, it was easy, as we could observer forever but with a StateFlow, I don’t see any way of doing something similar

take a look at `Turbine` by square. It's fantastic. <https://github.com/cashapp/turbine>

also you'll probably want to be looking at `runBlocking` for your tests

...and also avoiding `viewModelScope`. Testing becomes a bit easier if you inject a scope into the viewmodel via dependency injection and then implement `CoroutineScope` via interface delegation

```class MyViewModel @Inject constructor(
    @Named("viewModelScope") scope: CoroutineScope
) : ViewModel(), CoroutineScope by scope {

    override fun onCleared() {
        super.onCleared()
        cancel()
    }
}

@Test fun testFoo() = runBlocking { // this: CoroutineScope
    val viewModel = MyViewModel(this)

    viewModel.someFlow.test { ... }
}```

thanks <@U5D6V79TL>! I tried but I get this:

```java.lang.NoSuchMethodError: app.cash.turbine.FlowTurbineKt.test-f_gJSvk$default(Lkotlinx/coroutines/flow/Flow;DLkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;ILjava/lang/Object;)Ljava/lang/Object;```

That's strange. Did you add is as a `testImplementstion`? Also you can try asking questions over at <#C5HT9AL7Q|squarelibraries>