Develop Reference

How do I check the value changed in unit test (Android)

`I am having a hard time getting the middle? value of a stateFlow and checking using assertTrue
Here is my code for testing
fun initData() = viewModelScope.launch {
modifiableUiState.emit(UiState.Loading)
try {
testSomeThing()
modifiableUiState.emit(UiState.Loaded)
} catch (e: Exception) {
modifiableUiState.emit(UiState.Error(e))
} finally {
modifiableUiState.emit(UiState.Idle)
}
}
and my test code
#Test
fun load_store_data_succeed() = runTest {
// given
var uiState: PaySettingBalanceNotificationViewModel.UiState? = null
val collectJob = launch {
viewModel.uiState.collect { uiState = it }
}
// when
viewModel.initMandatoryData()
runCurrent()
// then
assertTrue(uiState is PaySettingBalanceNotificationViewModel.UiState.InitialDataLoaded)
collectJob.cancel()
}
since in finally block it will emit Idle, I can't check if the value has changed to InitialDataLoaded. Is there a way I can check the history? of a value for testing?`

calling an api multiple times using WorkManager in android

I want to call an api multiple times using WorkManager.
where idsArrayList is a list of ids.
I send each id in the api as Path to get response and similarly for other ids.
I want the workManager to return success after it has called api for all ids.
But the problem is WorkManager only returns SUCCESS for one id from the list. This is the first time I'm using WorkManager and I tried starting work manager for every id too by iterating over idsList one by one and making instance of workManger for every id in the for loop. But I thought sending the idsList as data in the workmanager and then itering over ids from inside doWork() would be better, but it's not working like I want and I don't understand why. Here's my code:
class MyWorkManager(appContext: Context, workerParams: WorkerParameters):
Worker(appContext, workerParams) {
private lateinit var callGrabShifts: Call<ConfirmStatus>
override fun doWork(): Result {
val idsList = inputData.getStringArray("IDS_LIST")
val idsArrayList = idsList?.toCollection(ArrayList())
var response = ""
if (idsArrayList != null) {
try {
response = callConfirmShiftApi(idsArrayList)
if (response.contains("CONFIRM")) {
return Result.success()
}
} catch (e: Exception) {
e.printStackTrace()
return Result.failure()
}
}
return Result.retry()
}
private fun callConfirmShiftApi(idsArrayList: ArrayList<String>): String {
var response = ""
for ((index, id) in idsArrayList.withIndex()) {
response = callApiForId(id)
if(index == idsArrayList.lastIndex) {
response = "CONFIRM"
}
}
return response
}
private fun callApiForId(id: String): String {
var shiftGrabStatus = ""
callGrabShifts = BaseApp.apiInterface.confirmGrabAllShifts(BaseApp.userId, id)
callGrabShifts.enqueue(object : Callback<ConfirmStatus> {
override fun onResponse(call: Call<ConfirmStatus>, response: Response<ConfirmStatus>) {
if (response.body() != null) {
shiftGrabStatus = response.body()!!.status
if (shiftGrabStatus != null) {
if (shiftGrabStatus.contains("CONFIRM")) {
val shiftNumber = ++BaseApp.noOfShiftsGrabbed
sendNotification(applicationContext)
shiftGrabStatus = "CONFIRM"
return
} else {
shiftGrabStatus = "NOT CONFIRM"
return
}
} else {
shiftGrabStatus = "NULL"
return
}
} else {
shiftGrabStatus = "NULL"
return
}
}
override fun onFailure(call: Call<ConfirmStatus>, t: Throwable) {
shiftGrabStatus = "FAILURE"
return
}
})
return shiftGrabStatus
}
}
And this is the code where I'm starting the WorkManager:
private fun confirmShiftApi(availableShiftsIdList: ArrayList<String>) {
val data = Data.Builder()
data.putStringArray("IDS_LIST", availableShiftsIdList.toArray(arrayOfNulls<String>(availableShiftsIdList.size)))
val oneTimeWorkRequest = OneTimeWorkRequestBuilder<MyWorkManager>().setInputData(data.build())
.build()
WorkManager.getInstance(applicationContext).enqueue(oneTimeWorkRequest)
WorkManager.getInstance(this).getWorkInfoByIdLiveData(oneTimeWorkRequest.id)
.observe(this, Observer { workInfo: WorkInfo? ->
if (workInfo != null && workInfo.state.isFinished) {
val progress = workInfo.progress
}
Log.d("TESTING", "(MainActivity) : observing work manager - workInfo?.state - ${workInfo?.state}")
})
}
Any suggestions what I might be doing wrong or any other alternative to perform the same? I chose workmanager basicaly to perform this task even when app is closed and for learning purposes as I haven't used WorkManager before. But would switch to other options if this doesn't work.

I tried the following things:
removed the 'var response line in every method that I'm using to set the response, though I added it temporarily just for debugging earlier but it was causing an issue.
I removed the check for "CONFIRM" in doWork() method and just made the api calls, removed the extra return lines.
I tried adding manual delay in between api calls for each id.
I removed the code where I'm sending the ids data from my activity before calling workmanager and made the api call to fetch those ids inside workmanager and added more delay in between those calls to that keep running in background to check for data one round completes(to call api for all ids that were fetched earlier, it had to call api again to check for more ids on repeat)
I removed the extra api calls from onRestart() and from other conditons that were required to call api again.
I tested only one round of api calls for all ids with delay and removed the repeated call part just to test first. Didn't work.
None of the above worked, it just removed extra lines of code.
This is my final code that is tested and It cleared my doubt. Though it didn't fix this issue as the problem was because of backend server and Apis were returning failure in onResponse callback for most ids(when calls are made repeatedly using a for loop for each id) except first id and randomly last id from the list sometimes(with delay) for the rest of the ids it didn't return CONFIRM status message from api using Workmanager. Adding delay didn't make much difference.
Here's my Workmanager code:
class MyWorkManager(appContext: Context, workerParams: WorkerParameters):
Worker(appContext, workerParams) {
private lateinit var callGrabShifts: Call<ConfirmStatus>
override fun doWork(): Result {
val idsList = inputData.getStringArray("IDS_LIST")
val idsArrayList = idsList?.toCollection(ArrayList())
if (idsArrayList != null) {
try {
response = callConfirmShiftApi(idsArrayList)
if (response.contains("CONFIRM")) {
return Result.success()
}
} catch (e: Exception) {
e.printStackTrace()
return Result.failure()
}
}
return Result.success()
}
private fun callConfirmShiftApi(idsArrayList: ArrayList<String>): String {
for ((index, id) in idsArrayList.withIndex()) {
response = callApiForId(id)
Thread.sleep(800)
if(index == idsArrayList.lastIndex) {
response = "CONFIRM"
}
}
return response
}
private fun callApiForId(id: String): String {
callGrabShifts = BaseApp.apiInterface.confirmGrabAllShifts(BaseApp.userId, id)
callGrabShifts.enqueue(object : Callback<ConfirmStatus> {
override fun onResponse(call: Call<ConfirmStatus>, response: Response<ConfirmStatus>) {
if (response.body() != null) {
shiftGrabStatus = response.body()!!.status
if (shiftGrabStatus != null) {
if (shiftGrabStatus.contains("CONFIRM")) {
return
} else {
return
}
} else {
return
}
} else {
return
}
}
override fun onFailure(call: Call<ConfirmStatus>, t: Throwable) {
return
}
})
return shiftGrabStatus
}
Eventually this problem(when an individual call is made for an id, it always returns success but when i call the api for every id using a loop, it only returns success for first call and failure for others) was solved using Service, it didn't have a complete success rate from apis either, but for 6/11 ids the api returned success(400ms delay between each api call), so it served the purpose for now.

No exception/error when no internet coroutine + retrofit

I have the following setup
Service
// ItunesService
suspend fun searchItunesPodcast(#Query("term") term: String): Response<PodcastResponse>
Repository
// ItunesRepo
override suspend fun searchByTerm(term: String) = withContext(ioDispatcher) {
return#withContext itunesService.searchItunesPodcast(term)
}
ViewModel
fun searchPodcasts(term: String) {
viewModelScope.launch {
_res.value = Result.loading()
try {
val response = itunesRepo.searchByTerm(term)
if (response.isSuccessful) { // Nothing from here when no internet
_res.value = Result.success(response.body())
} else {
_res.value = Result.error(response.errorBody().toString())
}
} catch (e: Exception) {
_res.value = Result.exception(e)
}
}
}
Everything works great until i turn off mobile data/internet on my testing device. _res value stuck on Loading state. I have tried adding break point at if (response.isSuccessful) when there is no internet and it seams like val response = itunesRepo.searchByTerm(term) never returns how can I fix this

I switched to using Flow api on my Repository
override suspend fun searchPodcasts(term: String) = flow {
emit(Result.Loading)
try {
val res = itunesService.searchItunesPodcast(term)
if (res.isSuccessful)
emit(Result.Success(res.body()))
else
emit(Result.Error("Generic error: ${res.code()}"))
} catch (e: Exception) {
emit(Result.Error("Unexpected error", e))
}
}.flowOn(ioDispatcher)
Then collect the results on my ViewModels

Fragment popbackstack trigger lifecyclescope collect

Situation
I submit data setTripDeliver, the collect works fine (trigger LOADING and then SUCCESS). I pressed a button go to next fragment B (using replace). After that, I press back button (using popbackstack). the collect SUCCESS triggered.
Codes Related
These codes at the FragmentA.kt inside onViewCreated.
private fun startLifeCycle() {
viewLifecycleOwner.lifecycleScope.launch {
viewLifecycleOwner.lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
launch {
collectTripDeliver()
}
launch {
collectTripReattempt()
}
}
}
}
These codes when to submit data at a button setOnClickListener.
viewLifecycleOwner.lifecycleScope.launchWhenStarted {
viewModel.setTripDeliver(
verificationCode,
remark
)
}
Method to collect flow collectTripReattempt()
private suspend fun collectTripReattempt() {
viewModel.tripReattempt.collect {
when (it) {
is Resource.Initialize -> {
}
is Resource.Loading -> {
Log.i("???","collectTripReattempt loading")
handleSaveEarly()
}
is Resource.Success -> {
val error = it.data?.error
if (error == null) {
Tools.showToast(requireContext(), "Success Reattempt")
Log.i("???","collectTripReattempt Success")
} else {
Tools.showToast(requireContext(), "$error")
}
handleSaveEnding()
}
is Resource.Error -> {
handleSaveEnding()
}
}
}
}
Below codes are from ViewModel.
private val _tripDeliver =
MutableStateFlow<Resource<TripDeliverResponse>>(Resource.Initialize())
val tripDeliver: StateFlow<Resource<TripDeliverResponse>> = _tripDeliver
This method to call repository.
suspend fun setTripDeliver(
verificationCode: String?,
remark: String?
) {
_tripDeliver.value = Resource.Loading()
try {
val result = withContext(ioDispatcher) {
val tripDeliverParameter = DeliverParameter(
verificationCode,
remark
)
val response = appRepository.setTripDeliver(tripDeliverParameter)
Resource.getResponse { response }
}
_tripDeliver.value = result
} catch (e: Exception) {
when (e) {
is IOException -> _tripDeliver.value =
Resource.Error(messageInt = R.string.no_internet_connection)
else -> _tripDeliver.value =
Resource.Error("Trip Deliver Error: " + e.message)
}
}
}
Logcat
2021-07-09 19:56:10.946 7446-7446/com.package.app I/???: collectTripReattempt loading
2021-07-09 19:56:11.172 7446-7446/com.package.app I/???: collectTripReattempt Success
2021-07-09 19:56:17.703 7446-7446/com.package.app I/???: collectTripReattempt Success
As you can see, the last Success is called again AFTER I pressed back button (popbackstack)
Question
How to make it trigger once only? Is it the way I implement it is wrong? Thank you in advance.

This is not problem of your implementation this is happening because of stateIn() which use used in your viewModel to convert regular flow into stateFlow
If according to your code snippet the success is triggered once again, then why not loading has triggered?
as per article, it is showing the latest cached value when you left the screen and came back you got the latest cached value on view.
Resource:
https://medium.com/androiddevelopers/migrating-from-livedata-to-kotlins-flow-379292f419fb
The latest value will still be cached so that when the user comes back to it, the view will have some data immediately.

I have found the solution, thanks to #Nurseyit Tursunkulov for giving me a clue. I have to use SharedFlow.
At the ViewModel, I replace the initialize with these:
private val _tripDeliver = MutableSharedFlow<Resource<TripDeliverResponse>>(replay = 0)
val tripDeliver: SharedFlow<Resource<TripDeliverResponse>> = _tripDeliver
At the replay I have to use 0, so this SharedFlow will trigger once. Next, change _tripDeliver.value to _tripDeliver.emit() like the codes below:
fun setTripDeliver(
verificationCode: String?,
remark: String?
) = viewModelScope.launch {
_tripDeliver.emit(Resource.Loading())
if (verificationCode == null && remark == null) {
_tripDeliver.emit(Resource.Error("Remark cannot be empty if verification is empty"))
return#launch
}
try {
val result = withContext(ioDispatcher) {
val tripDeliverParameter = DeliverParameter(
verificationCode,
remark,
)
val response = appRepository.setTripDeliver(tripDeliverParameter)
Resource.getResponse { response }
}
_tripDeliver.emit(result)
} catch (e: Exception) {
when (e) {
is IOException -> _tripDeliver.emit(Resource.Error(messageInt = R.string.no_internet_connection))
else -> _tripDeliver.emit(Resource.Error("Trip Deliver Error: " + e.message))
}
}
}
I hope this answer will help the others also.

I think this is because of coldFlow, you need a HotFlow. Another option is to try to hide and show fragment, instead of replacing. And yet another solution is to keep this code in viewModel.

In my opinion, I think your way of using coroutines in lifeScope is incorrect. After the lifeScope status of FragmentA is at Started again, the coroutine will be restarted:
launch {
collectTripDeliver()
}
launch {
collectTripReattempt()
}
So I think: You need to modify this way:
private fun startLifeCycle() {
viewLifecycleOwner.lifecycleScope.launch {
launch {
collectTripDeliver()
}
launch {
collectTripReattempt()
}
}
}

How to launch a coroutine from within a class without using init?

I've got the following class:
class SomeApiRemoteSource (private var someApi: SomeApi)
{
private val someData = MutableLiveData<Map<String, String>>()
init
{
GlobalScope.launch(Dispatchers.IO)
{
try
{
val response = someApi.getSomeData(SomeApi.API_KEY).awaitResponse()
if(response.isSuccessful)
someData.postValue(response.body()?.data)
else
someData.postValue(emptyMap())
}
catch (e: Exception)
{
Log.e("ds error", e.message!!)
someData.postValue(emptyMap())
}
}
}
fun getSomeData(): MutableLiveData<Map<String, String>>
{
return someData
}
}
Everything works fine, but is there a way to get the same result without using the init? What if I need to run another API getter call? Should I just run another coroutine right below that 1st one? That seems inefficient.

You can create a function containing your coroutine and you can call it any number of times.
class SomeApiRemoteSource (private var someApi: SomeApi)
{
private val someData = MutableLiveData<Map<String, String>>()
private var apiJob: Job? = null
init
{
getDataFromAPI()
}
fun getDataFromAPI(){
// Cancel previous job if already running
apiJob?.cancel()
apiJob = GlobalScope.launch(Dispatchers.IO)
{
try
{
val response = someApi.getSomeData(SomeApi.API_KEY).awaitResponse()
if(response.isSuccessful)
someData.postValue(response.body()?.data)
else
someData.postValue(emptyMap())
}
catch (e: Exception)
{
Log.e("ds error", e.message!!)
someData.postValue(emptyMap())
}
}
}
fun getSomeData(): MutableLiveData<Map<String, String>>
{
return someData
}
}

I got it. Took some inspiration from previous answers.
class FixerRemoteSource (private var fixerApi: FixerApi)
{
suspend fun getAllSupportedSymbols(): Map<String, String>
{
val response = fixerApi.getAllSupportedSymbols(FixerApi.API_KEY)
return if(response.isSuccessful) response.body()?.symbols!! else emptyMap()
}
}
The problem that was blocking me was that the app kept crashing while I debugged the coroutine stuff. Removed the breaking points out of the coroutines and everything was fine.