Nearly equal Unit tests behave differently - android-studio

Question

I wrote an unit test to test if a Map is updated every second. In the code I inserted some println statements to see if the function really is called. The test runs indefinitely until I abort the test, showing the println in system.out. So the function works correctly, but my test does not.
Testcode and programcode are below.
#Test
fun test_count_is_updated_using_turbine(){
runTest {
testScheduler.runCurrent()
viewmodelUnderTest.runningTaskMap.test(2.seconds){
val firstCount = awaitItem()
assertThat(firstCount).containsKey(1)
viewmodelUnderTest.startUpdates()
val secondCount = awaitItem()
viewmodelUnderTest.stopUpdates()
cancelAndIgnoreRemainingEvents()
assertThat(firstCount).isEqualTo(0)
assertThat(secondCount).isEqualTo(1)
}
}
}
Program code in viewmodel:( RunningMapState is initialized with a value when the viewmodel is initialized, so it is not an empty map.)
var runningTaskState:Map<Int, RunningTaskView> = mapOf()
private val _runningTaskMap = MutableStateFlow<Map<Int, RunningTaskView>>(mapOf())
val runningTaskMap: StateFlow<Map<Int, RunningTaskView>>
get()=_runningTaskMap
suspend fun updateRunningTasks() {
if (runningTaskState.isNotEmpty()) {
println("Before update:"+runningTaskState)
runningTaskState.forEach {
it.value.duration += 1000L
}
println("After update:"+runningTaskState)
//val tempMap = runningTaskState.toMap()
_runningTaskMap.update{ runningTaskState }
}
else{
println("map empty")
}
}
fun startUpdates(){
val previousJob = timerJob
timerJob = viewModelScope.launch (dispatcher){
previousJob?.cancelAndJoin()
while (isActive) {
delay(1000L)
updateRunningTasks()
}
}
}
fun stopUpdates(){
viewModelScope.launch(dispatcher) {
timerJob?.cancelAndJoin()
}
}
To test the testcode I wrote a sample program replacing the map with a Integer. This test functions as expected and passes. Viewmodelcode and testcode are nearly identical.
See below code:
#Test
fun test_count_is_updated_using_turbine(){
runTest {
testDispatcher.scheduler.runCurrent()
viewmodelUnderTest.countFlow.test(2.seconds){
val firstCount = awaitItem()
val started = viewmodelUnderTest.startTimer()
val secondCount = awaitItem()
viewmodelUnderTest.stoptimer()
cancelAndIgnoreRemainingEvents()
assertThat(started).isTrue()
assertThat(firstCount).isEqualTo(0)
assertThat(secondCount).isEqualTo(1)
}
}
}
Viewmodel:
var count = 0
var countFlow = MutableStateFlow<Int>(0)
fun updateTimer(){
count++
countFlow.update { count }
println("count updated to $count")
}
fun stoptimer(){
viewModelScope.launch {
timerJob?.cancelAndJoin()
}
}
fun startTimer():Boolean{
val previousJob = timerJob
timerJob = viewModelScope.launch(dispatcher) {
previousJob?.cancelAndJoin()
println("start updating")
while(isActive) {
delay(1000L)
println("calling update")
updateTimer()
println("update called")
}
}
println("TimerTest is active: "+timerJob?.isActive?.toString()?:"not initialized")
return timerJob?.isActive?:false
}
Can anyone explain why the first test is not finishing?