JoseAlcerreca

// Copyright 2022 Google LLC.
// SPDX-License-Identifier: Apache-2.0

fun ComposeContentTestRule.waitUntilNodeCount(
    matcher: SemanticsMatcher,
    count: Int,
    timeoutMillis: Long = 1_000L
) {
    this.waitUntil(timeoutMillis) {
        this.onAllNodes(matcher).fetchSemanticsNodes().size == count

JoseAlcerreca

// Click on a button
composeTestRule.onNodeWithText("Continue").performClick()

// Wait until there's one element with a "Welcome" text
composeTestRule.waitUntil {
    composeTestRule
        .onAllNodesWithText("Welcome")
        .fetchSemanticsNodes().size == 1
}

JoseAlcerreca

composeTestRule.onNodeWithText("Continue¨) .performClick()
Thread.sleep(2000)  // don't do this
composeTestRule.onNodeWithText("Welcome").assertExists()

JoseAlcerreca

class MyRepo(dataSource: MyDataSource) {
    suspend fun getItems() {
        idlingResource.setBusy() // App is busy… test must wait.

        val result = dataSource.getTasks()

        idlingResource.setIdle() // App is idle, ready for next operation.
        return result
    }
}

JoseAlcerreca

val wrapped: IdlingResourceScheduler = Rx3Idler.wrap(myScheduler, "My Scheduler")
IdlingRegistry.getInstance().register(wrapped)

JoseAlcerreca

    @Test
    fun channelShareInTest() {

        val scope = TestCoroutineScope()
        val _channel = Channel<Int>(capacity = 2, onBufferOverflow = BufferOverflow.DROP_OLDEST)
        val exposedFlow: SharedFlow<Int> = _channel
            .consumeAsFlow().shareIn(scope, SharingStarted.WhileSubscribed())

        val testResults = mutableListOf<Int>()

JoseAlcerreca

    @Test
    fun channelConflatedTest() {

        val _channel = Channel<Int>(capacity = CONFLATED)
        val exposedFlow: Flow<Int> = _channel.receiveAsFlow()

        val testResults = mutableListOf<Int>()
        val testResults2 = mutableListOf<Int>()
        val testResults3 = mutableListOf<Int>()

JoseAlcerreca

onCreateView(...) {
    viewLifecycleOwner.lifecycleScope.launch {
        viewLifecycleOwner.lifecycle.repeatOnLifecycle(STARTED) {
            myViewModel.myUiState.collect { ... }
        }
    }
}

JoseAlcerreca

class MyViewModel(...) : ViewModel() {
    val result = userId.mapLatest { newUserId ->
        repository.observeItem(newUserId)
    }.stateIn(
        scope = viewModelScope, 
        started = WhileSubscribed(5000), 
        initialValue = Result.Loading
    )
}

JoseAlcerreca

val result: StateFlow<Result<UiState>> = someFlow
    .stateIn(
        scope = viewModelScope, 
        started = WhileSubscribed(5000), 
        initialValue = Result.Loading
    )