[测试]我们如何为DiffUtil编写测试用例?
val oldList = listOf("a", "b", 0)
val newList = listOf("a", "c", 0, 1)
我们如何编写一个特定的测试用例,即尚未针对新列表中相对于oldList进行修改的项目调用我们的onBindViewHolder
,这基本上是DiffUtil
要做的一切顺利吗?
关于我们如何侦听回收者视图本身的更改的任何想法?
我正在考虑使用registerAdapterDataObserver(AdapterDataObserver)
,在这里我们可以覆盖onItemRangeChanged
并听取更改,但是在“测试”中使用这种方法并不好。
答案 0 :(得分:0)
DiffUtil不会再次重新绑定任何相同的项目,因此根据要求,如果此测试用例与DiffUtil以外的任何其他实现一起运行,它将失败。
@Test
fun testAdapter_noRebinding() {
val adapter = getAdapterObject()
lateinit var dataObserver: RecyclerView.AdapterDataObserver
var doesRebind = false
val oldList = listOf("a", "b", 0)
val newList = listOf("a", "b", 0)
ActivityScenario.launch(AdapterActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
dataObserver = object: RecyclerView.AdapterDataObserver(){
override fun onChanged() {
doesRebind = true
}
override fun onItemRangeInserted(positionStart: Int, itemCount: Int) {
assertThat(positionStart).isEqualTo(0)
assertThat(itemCount).isEqualTo(3)
}
override fun onItemRangeChanged(positionStart: Int, itemCount: Int) {
doesRebind = true
}
override fun onItemRangeChanged(positionStart: Int, itemCount: Int, payload: Any?) {
doesRebind = true
}
}
adapter.registerAdapterDataObserver(dataObserver)
}
scenario.onActivity { activity ->
val liveData = getList(activity)
liveData.value = oldList
}
scenario.onActivity { activity ->
val liveData = getList(activity)
liveData.value = newList
}
scenario.onActivity { activity ->
assertThat(doesRebind).isEqualTo(false)
adapter.unregisterAdapterDataObserver(dataObserver)
}
}
}
使用Mockito添加了测试用例,但这些测试用例仅在robolectric上通过,而不在意式浓缩咖啡上
@Test
fun testBindableAdapter_incomingSameData_noRebindingShouldHappen() {
val adapter = createMultiViewTypeNoDataBindingBindableAdapter()
BindableAdapterTestFragmentPresenter.testBindableAdapter = adapter
val oldList = listOf(STR_VALUE_1, STR_VALUE_0, INT_VALUE_1).toMutableList()
val newList = listOf(STR_VALUE_1, STR_VALUE_0, INT_VALUE_1).toMutableList()
val fakeObserver = mock(RecyclerView.AdapterDataObserver::class.java)
ActivityScenario.launch(BindableAdapterTestActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
adapter.registerAdapterDataObserver(fakeObserver)
val liveData = getRecyclerViewListLiveData(activity)
liveData.value = oldList
verify(fakeObserver, times(1)).onItemRangeInserted(0, 3)
val liveDataNew = getRecyclerViewListLiveData(activity)
liveDataNew.value = newList
verify(fakeObserver, never()).onChanged()
adapter.unregisterAdapterDataObserver(fakeObserver)
}
}
}
@Test
fun testBindableAdapter_removeOneItem_verifyChangeOnlyOneItem() {
val adapter = createMultiViewTypeNoDataBindingBindableAdapter()
BindableAdapterTestFragmentPresenter.testBindableAdapter = adapter
val oldList = listOf(STR_VALUE_1, STR_VALUE_1, INT_VALUE_1).toMutableList()
val newList = listOf(STR_VALUE_1, INT_VALUE_1).toMutableList()
val fakeObserver = mock(RecyclerView.AdapterDataObserver::class.java)
ActivityScenario.launch(BindableAdapterTestActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
adapter.registerAdapterDataObserver(fakeObserver)
val liveData = getRecyclerViewListLiveData(activity)
liveData.value = oldList
val liveDataNew = getRecyclerViewListLiveData(activity)
liveDataNew.value = newList
verify(fakeObserver, times(1)).onItemRangeRemoved(0, 1)
adapter.unregisterAdapterDataObserver(fakeObserver)
}
}
}
@Test
fun testBindableAdapter_insertOneItem_verifyChangeOnlyOneItem() {
val adapter = createMultiViewTypeNoDataBindingBindableAdapter()
BindableAdapterTestFragmentPresenter.testBindableAdapter = adapter
val oldList = listOf(STR_VALUE_1, INT_VALUE_1).toMutableList()
val newList = listOf(STR_VALUE_1, STR_VALUE_1, INT_VALUE_1).toMutableList()
val fakeObserver = mock(RecyclerView.AdapterDataObserver::class.java)
ActivityScenario.launch(BindableAdapterTestActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
adapter.registerAdapterDataObserver(fakeObserver)
val liveData = getRecyclerViewListLiveData(activity)
liveData.value = oldList
val liveDataNew = getRecyclerViewListLiveData(activity)
liveDataNew.value = newList
verify(fakeObserver, times(1)).onItemRangeInserted(0, 1)
adapter.unregisterAdapterDataObserver(fakeObserver)
}
}
}
@Test
fun testBindableAdapter_moveOneItem_verifyNoRecreatingWholeList() {
val adapter = createMultiViewTypeNoDataBindingBindableAdapter()
BindableAdapterTestFragmentPresenter.testBindableAdapter = adapter
val oldList = listOf(STR_VALUE_1, STR_VALUE_0, INT_VALUE_1).toMutableList()
val newList = listOf(INT_VALUE_1, STR_VALUE_0, STR_VALUE_1).toMutableList()
val fakeObserver = mock(RecyclerView.AdapterDataObserver::class.java)
ActivityScenario.launch(BindableAdapterTestActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
adapter.registerAdapterDataObserver(fakeObserver)
val liveData = getRecyclerViewListLiveData(activity)
liveData.value = oldList
val liveDataNew = getRecyclerViewListLiveData(activity)
liveDataNew.value = newList
verify(fakeObserver, times(1)).onItemRangeChanged(2, 1, null)
verify(fakeObserver, times(1)).onItemRangeChanged(0, 1, null)
adapter.unregisterAdapterDataObserver(fakeObserver)
}
}
}
@Test
fun testBindableAdapter_updateOneItemContent_verifyOneItemUpdated() {
val adapter = createMultiViewTypeNoDataBindingBindableAdapter()
BindableAdapterTestFragmentPresenter.testBindableAdapter = adapter
val oldList = listOf(STR_VALUE_1, STR_VALUE_0, INT_VALUE_1).toMutableList()
val newList = listOf(STR_VALUE_1, STR_VALUE_1, INT_VALUE_1).toMutableList()
val fakeObserver = mock(RecyclerView.AdapterDataObserver::class.java)
ActivityScenario.launch(BindableAdapterTestActivity::class.java).use { scenario ->
scenario.onActivity { activity ->
adapter.registerAdapterDataObserver(fakeObserver)
val liveData = getRecyclerViewListLiveData(activity)
liveData.value = oldList
val liveDataNew = getRecyclerViewListLiveData(activity)
liveDataNew.value = newList
verify(fakeObserver, times(1)).onItemRangeChanged(1, 1, null)
adapter.unregisterAdapterDataObserver(fakeObserver)
}
}
}
java.lang.RuntimeException: Wanted but not invoked:
adapterDataObserver.onItemRangeRemoved(0, 1);
-> at org.oppia.app.recyclerview.BindableAdapterTest$testBindableAdapter_removeOneItem_verifyChangeOnlyOneItem$$inlined$use$lambda$1.perform(BindableAdapterTest.kt:303)
Actually, there were zero interactions with this mock.
java.lang.RuntimeException: Wanted but not invoked:
adapterDataObserver.onItemRangeChanged(
2,
1,
null
);
-> at org.oppia.app.recyclerview.BindableAdapterTest$testBindableAdapter_moveOneItem_verifyNoRecreatingWholeList$$inlined$use$lambda$1.perform(BindableAdapterTest.kt:349)
Actually, there were zero interactions with this mock.