checkValues.kt

@OptIn(ExperimentalCoroutinesApi::class)
fun <T : Any> Flow<T>.checkValues(
    vararg actions: suspend () -> Unit,
    assert: List<T>.() -> Unit,
) = runTest {
    // replace main & viewModelScope with the standard test dispatcher
    Dispatchers.setMain(StandardTestDispatcher(testScheduler))
    val results = mutableListOf<T>()

    // collect the flow on an unconfined test dispatcher
    val job = this@checkValues
        .onEach { results.add(it) }
        .launchIn(this + UnconfinedTestDispatcher(testScheduler))

    actions.forEach { action ->
        action()
        // ensure any queued actions are run
        advanceUntilIdle()
    }

    results.assert()

    job.cancel()
    Dispatchers.resetMain()
}