测试协程中的可观察字段更改

Question

我正在编写单元测试，当我在执行挂起函数之前和之后立即更改可观察值时，我遇到了这种特殊情况。我想编写一个单元测试来检查该值是否正确更改了两次。

这是方法：

fun doSomething() {
viewModelScope.launch(ioDispatcher) {
try {
viewModelScope.launch(Dispatchers.Main) {
commandLiveData.value = Pair(CANCEL_TIMER, null)
}
isProgress.set(true) //need to test it was set to true in one test
checkoutInteractor.doSomethingElse().run {
handleResult(this)
}
isProgress.set(false) //need to test it was set to false here in another test
} catch (ex: java.lang.Exception) {
handleHttpError(ex)
isProgress.set(false)
}
}
}

编写测试时，我调用doSomething()但我不确定如何检测该值在checkoutInteractor.doSomethingElse调用之前设置为 true，在调用之后设置为 false。

这是我的测试

@Test
fun `test doSomething enables progress`() {
runBlockingTest {
doReturn(Response()).`when`(checkoutInteractor). checkoutInteractor.doSomethingElse()
viewModel.doSomething()
assertTrue(viewModel.isProgress.get()) //fails obviously as the value was already set to false after the `doSomethingElse` was executed. 
}
}

顺便说一句，isProgress是一个ObservableBoolean

Answer 1

您需要模拟或监视isProgress和checkoutInteractor字段，以记录和验证其方法的执行。

1. 通过模拟或间谍isProcess并checkoutInteractor进入您的班级。
2. 执行doSomething()
3. 验证set()和doSomethingElse()功能的顺序

例：

@Test
fun `test doSomething enables progress`() {
runBlockingTest {
val checkoutInteractor = Mockito.spy(CheckoutInteractor())
val isProcess = Mockito.spy(ObservableBoolean(true))
val viewModel = ViewModel(isProcess, checkoutInteractor)
viewModel.doSomething()
val inOrder = inOrder(isProcess, checkoutInteractor)
inOrder.verify(isProcess).set(true)
inOrder.verify(checkoutInteractor).doSomethingElse()
inOrder.verify(isProcess).set(false)
}
}