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How to test Coroutines
in ViewModel
2019.11.11 potatotips #66
Hiroyuki Kusu ( @hkusu_ )
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About me
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class MainViewModel(private val itemRepository: ItemRepository) : ViewModel() {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() {
viewModelScope.launch {
_itemListStatus.value = Status.Loading
runCatching {
withContext(Dispatchers.IO) {
itemRepository.getItemList()
}
}
.onSuccess {
_itemListStatus.value = Status.Success(it)
}
.onFailure {
_itemListStatus.value = Status.Failure(it)
}
}
}
}
// ...
sealed class Status {
object Loading : Status()
data class Success(val data: T) : Status()
data class Failure(val throwable: Throwable) : Status()
}
MainViewModel
͜ͷ ViewModel ͷςετίʔυΛॻ͍ͯΈΔ
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@ExperimentalCoroutinesApi
class TestCoroutinesRule : TestWatcher() {
override fun starting(description: Description?) {
super.starting(description)
Dispatchers.setMain(Dispatchers.Unconfined)
}
override fun finished(description: Description?) {
super.finished(description)
Dispatchers.resetMain()
}
}
ϝΠϯεϨουΛࠩ͠ସ͑Δ
(ରviewModelScope༻)
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@ExperimentalCoroutinesApi
class MainViewModelTest {
@get:Rule
val instantTaskExecutorRule = InstantTaskExecutorRule()
@get:Rule
var testCoroutinesRule = TestCoroutinesRule()
private lateinit var mainViewModel: MainViewModel
@MockK
private lateinit var itemRepository: ItemRepository
@Before
fun setUp() {
MockKAnnotations.init(this, relaxed = true)
mainViewModel = MainViewModel(itemRepository)
}
@Test
fun `MainViewModel#loadItemList()`() {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mockk>>>(relaxUnitFun = true)
mainViewModel.itemListStatus.observeForever(observer)
// When
mainViewModel.loadItemList()
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
}
MainViewModelTest
← ඪ४ͷϧʔϧ(ରLiveData༻)
← ઌ΄Ͳ࡞ͬͨϧʔϧ
← RepositoryϞοΫ͢Δ
← LiveDataͷObserverϞοΫ
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No content
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class MainViewModel(private val itemRepository: ItemRepository) : ViewModel() {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() {
viewModelScope.launch {
_itemListStatus.value = Status.Loading
delay(5000) // dleay
runCatching {
withContext(Dispatchers.IO) {
Thread.sleep(2000) // ॏ͍ॲཧ
delay(4000) // delay
itemRepository.getItemList()
}
}
.onSuccess {
_itemListStatus.value = Status.Success(it)
}
.onFailure {
_itemListStatus.value = Status.Failure(it)
}
}
}
}
ͨͩ͠..
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No content
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// ...
@Test
fun `MainViewModel#loadItemList()`() {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mockk>>>(relaxUnitFun = true)
mainViewModel.itemListStatus.observeForever(observer)
// When
mainViewModel.loadItemList()
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
MainViewModelTest
← ϝιουͷॲཧ͕ऴΘΔͷΛͯͯͳ͍
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class MainViewModel(private val itemRepository: ItemRepository) : ViewModel() {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() {
viewModelScope.launch {
_itemListStatus.value = Status.Loading
delay(5000) // dleay
runCatching {
withContext(Dispatchers.IO) {
Thread.sleep(2000) // ॏ͍ॲཧ
delay(4000) // delay
itemRepository.getItemList()
}
}
.onSuccess {
_itemListStatus.value = Status.Success(it)
}
.onFailure {
_itemListStatus.value = Status.Failure(it)
}
}
}
}
← MVVMͰઃܭ͢Δͱવϝιουͷ ΓUnit
MainViewModel
Ͳ͏ରࡦ͢Δ͔ʁ
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ํ๏ᶃ
ViewModelͷϝιουͷ
ΓͷܕΛ Job ܕʹ͢Δ
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class MainViewModel(private val itemRepository: ItemRepository) : ViewModel() {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() = viewModelScope.launch {
_itemListStatus.value = Status.Loading
Thread.sleep(2000) // ॏ͍ॲཧ
delay(5000) // dleay
runCatching {
withContext(Dispatchers.IO) {
Thread.sleep(2000) // ॏ͍ॲཧ
delay(4000) // delay
itemRepository.getItemList()
}
}
.onSuccess {
_itemListStatus.value = Status.Success(it)
}
.onFailure {
_itemListStatus.value = Status.Failure(it)
}
}
}
MainViewModel
← JobܕΛฦ͢
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// ...
@Test
fun `MainViewModel#loadItemList()`() {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mockk>>>(relaxUnitFun = true)
mainViewModel.itemListStatus.observeForever(observer)
// When
runBlocking {
mainViewModel.loadItemList().join()
}
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
MainViewModelTest
JobܕΛjoin()ͯ͠தஅؔԽ
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• ςετͷҝʹΓͷܕΛมߋ͢Δ͜ͱʹ߅͕
͋Δ
• 1ͭͷϝιουͰίϧʔνϯΛෳىಈ͍ͨ͠
߹ඍົʁ
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ํ๏ᶄ
ςετ࣌ʹ CoroutineScope
Λࠩ͠ସ͑Δ
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class MainViewModel(
private val itemRepository: ItemRepository,
coroutineScope: CoroutineScope = MainScope()
) : ViewModel(), CoroutineScope by coroutineScope {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() {
launch {
_itemListStatus.value = Status.Loading
Thread.sleep(2000) // ॏ͍ॲཧ
delay(5000) // dleay
runCatching {
withContext(Dispatchers.IO) {
Thread.sleep(2000) // ॏ͍ॲཧ
delay(4000) // delay
itemRepository.getItemList()
}
}
// ...
override fun onCleared() {
cancel()
}
// ...
MainViewModel
viewModelScopeΛར༻͍ͯ͠ͳ͍ͷͰࣗલͰί
ϧʔνϯΛΩϟϯηϧ͢Δίʔυ
ίϯετϥΫλͰCoroutineScopeΛࠩ
͠ม͑ΕΔΑ͏ʹ͓ͯ͘͠
.. লུͨ͠߹ MainScope()
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// ...
// @get:Rule
// var testCoroutinesRule = TestCoroutinesRule()
private lateinit var mainViewModel: MainViewModel
@MockK
private lateinit var itemRepository: ItemRepository
@Before
fun setUp() {
MockKAnnotations.init(this, relaxed = true)
// mainViewModel = MainViewModel(itemRepository)
}
@Test
fun `MainViewModel#loadItemList()`() {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mockk>>>(relaxUnitFun = true)
runBlocking {
mainViewModel = MainViewModel(itemRepository, this)
mainViewModel.itemListStatus.observeForever(observer)
// When
mainViewModel.loadItemList()
}
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
MainViewModelTest
← runBlockingͷείʔϓΛViewModel
͢
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• viewModelScope ͏͜ͱ͕Ͱ͖ͳ͍
• ςετίʔυͰ runBlocking ͷϒϩοΫͰ
ViewModel ͷΠϯελϯεΛ࡞͢Δඞཁ͕͋
Γςετίʔυ͕ॻ͖ͮΒ͍
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ํ๏ᶅ
TestCoroutineDispatcher
Λ͏
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open class DispatcherProvider {
open val main: CoroutineDispatcher = Dispatchers.Main
open val io: CoroutineDispatcher = Dispatchers.IO
}
// ...
class MainViewModel(
private val itemRepository: ItemRepository,
private val dispatcherProvider: DispatcherProvider = DispatcherProvider()
) : ViewModel() {
private val _itemListStatus = MutableLiveData>>()
val itemListStatus = _itemListStatus.distinctUntilChanged()
fun loadItemList() {
viewModelScope.launch {
_itemListStatus.value = Status.Loading
Thread.sleep(2000) // ॏ͍ॲཧ
delay(5000) // dleay
runCatching {
withContext(dispatcherProvider.io) {
Thread.sleep(2000) // ॏ͍ॲཧ
delay(4000) // delay
itemRepository.getItemList()
}
}
// ...
MainViewModel
Dispatchers.XX ࠩ͠ସ͑ΕΔΑ͏ʹ
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@ExperimentalCoroutinesApi
class TestCoroutinesRule : TestWatcher() {
val testCoroutineDispatcher = TestCoroutineDispatcher()
override fun starting(description: Description?) {
super.starting(description)
Dispatchers.setMain(testCoroutineDispatcher)
}
override fun finished(description: Description?) {
super.finished(description)
Dispatchers.resetMain()
testCoroutineDispatcher.cleanupTestCoroutines()
}
}
@ExperimentalCoroutinesApi
class TestDispatcherProvider(testCoroutineDispatcher: TestCoroutineDispatcher) : DispatcherProvider() {
override val main: CoroutineDispatcher = testCoroutineDispatcher
override val io: CoroutineDispatcher = testCoroutineDispatcher
}
TestUtils.kt
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// ...
@Before
fun setUp() {
MockKAnnotations.init(this, relaxed = true)
mainViewModel = MainViewModel(itemRepository, TestDispatcherProvider(testCoroutinesRule.testCoroutineDispatcher))
}
@Test
fun `MainViewModel#loadItemList()`() = testCoroutinesRule.testCoroutineDispatcher.runBlockingTest {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mockk>>>(relaxUnitFun = true)
mainViewModel.itemListStatus.observeForever(observer)
// When
mainViewModel.loadItemList()
advanceUntilIdle() // ςετର͕delayΛར༻͍ͯ͠Δ߹ͷΈهड़
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
MainViewModelTest
ςετ༻ͷεϨουͷΈͰίϧʔνϯ
Λಈ͔ͭͭ͠delayΛίϯτϩʔϧ
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ͪΐͬͱศརʹ͢Δ
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@ExperimentalCoroutinesApi
class TestCoroutinesRule : TestWatcher() {
private val testCoroutineDispatcher = TestCoroutineDispatcher()
override fun starting(description: Description?) {
super.starting(description)
Dispatchers.setMain(testCoroutineDispatcher)
}
override fun finished(description: Description?) {
super.finished(description)
Dispatchers.resetMain()
testCoroutineDispatcher.cleanupTestCoroutines()
}
fun runBlockingTest(block: suspend TestCoroutineScope.() -> Unit) {
testCoroutineDispatcher.runBlockingTest {
block.invoke(this)
}
}
val dispatcherProvider: DispatcherProvider
get() = TestDispatcherProvider(testCoroutineDispatcher)
}
@ExperimentalCoroutinesApi
class TestDispatcherProvider(testCoroutineDispatcher: TestCoroutineDispatcher) : DispatcherProvider() {
override val main: CoroutineDispatcher = testCoroutineDispatcher
override val io: CoroutineDispatcher = testCoroutineDispatcher
}
fun LiveData.createTestObserver(): Observer {
val observer: Observer = mockk(relaxUnitFun = true)
this.observeForever(observer)
return observer
}
TestUtils.kt
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// ...
@Before
fun setUp() {
MockKAnnotations.init(this, relaxed = true)
mainViewModel = MainViewModel(itemRepository, testCoroutinesRule.dispatcherProvider)
}
@Test
fun `MainViewModel#loadItemList()`() = testCoroutinesRule.runBlockingTest {
// Given
val expectItemList = listOf(Item(1, "item1"), Item(2, "item2"))
coEvery { itemRepository.getItemList() } answers { expectItemList }
val observer = mainViewModel.itemListStatus.createTestObserver()
// When
mainViewModel.loadItemList()
advanceUntilIdle()
// Then
coVerify(exactly = 1) { itemRepository.getItemList() }
verifySequence {
observer.onChanged(Status.Loading)
observer.onChanged(Status.Success(expectItemList))
}
}
MainViewModelTest
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·ͱΊ
• ViewModel ্ͷ Coroutines ͷॲཧͷྃΛͬ
ͯςετͷ݁ՌΛݕূ͢Δํ๏Λ̏௨Γઆ໌ͨ͠
• جຊతʹ ํ๏ᶅ Ͱςετ͢ΕΑͦ͞͏
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Thank you !
@hkusu_
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ࢀߟ: build.gradle
implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0-rc01'
implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0-rc01'
implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-rc01'
// ...
testImplementation 'junit:junit:4.12'
testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.2.2'
testImplementation 'androidx.arch.core:core-testing:2.1.0'
testImplementation 'io.mockk:mockk:1.9.3'
testImplementation 'com.google.truth:truth:1.0'