无法在 Robolectric 中单击 RecyclerView 子项

Question

我正在为 MVP android 应用中的视图编写测试。在这些测试中，我使用的是 Robolectric 3.6.1。我运行遇到的问题是当我尝试使用 getChildAt() 单击 RecyclerView 内的视图时出现 NullPointerException。这只发生在整个测试 class 是运行时，而不是测试是孤立的运行时，这让我觉得我的设置有问题。如果我运行整个class第一个测试没有这个问题，但是其他的都有，所以这个问题似乎是在多次调用setUp()函数时出现的。

我做了一些研究并发现了 this post，但将其放入我的代码中并没有帮助。

@RunWith(RobolectricTestRunner.class)
public class MainActivityTest {

    private List<Measurement> measurements = Arrays.asList(new Measurement("Object A", Unit.CM), new Measurement("Object B", Unit.KG));
    private final int POSITION = 0;

    @Mock
    private MainMvpPresenter mainMvpPresenter;

    private MainActivity mainActivity;

    private RecyclerView measurementsRecyclerView;

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
        mainActivity = Robolectric.buildActivity(MainActivity.class).create().visible().get();
        mainActivity.setMainMvpPresenter(mainMvpPresenter);

        measurementsRecyclerView = mainActivity.findViewById(R.id.measurementsList);
        mainActivity.updateMeasurements(measurements);
    }

    @Test
    public void setUpCorrectly(){
        assertThat(measurementsRecyclerView.getChildCount(), is(measurements.size()));
    }

    @Test
    public void onItemClicked_ShouldCallPresenter() {
        measurementsRecyclerView.findViewHolderForAdapterPosition(POSITION).itemView.performClick();
        verify(mainMvpPresenter).measurementClicked(POSITION);
    }
}

这是我得到的错误：

java.lang.NullPointerException
    at com.jakkaps.body_measurements.ui.main.MainActivityTest.onItemClicked_ShouldCallPresenter(MainActivityTest.java:64)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.robolectric.RobolectricTestRunner$HelperTestRunner.evaluate(RobolectricTestRunner.java:535)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.robolectric.internal.SandboxTestRunner.evaluate(SandboxTestRunner.java:249)
    at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:123)
    at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:42)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access[=12=]0(ParentRunner.java:58)
    at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268)
    at org.robolectric.internal.SandboxTestRunner.evaluate(SandboxTestRunner.java:77)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131

)

Answer 1

我并没有真正找到解决实际问题的方法，我只是试了一下直到它起作用。我必须做的是不要在 setUp() 函数中调用 measurementsRecyclerView = mainActivity.findViewById(R.id.measurementsList);，而是在每个测试中单独调用。我还必须调用 mainActivity.updateMeasurements(measurements); 两次。

结果很乱，所以我建议任何人找到自己的解决方案。

无法在 Robolectric 中单击 RecyclerView 子项

Can't click on RecyclerView child in Robolectric

android

android-recyclerview

robolectric