android - Robolectric:如何测试包含 SherlockFragment 的 Activity ？

Question

我已经从这里、github 和 robolectric 博客阅读了很多链接，但还没有找到可行的解决方案(已经使用 Robolectric 2.0 alpha 2)。

更新:即使我们将 SherlockFragment 替换为 android.support.v4.app.Fragment 也会出现此问题。

遵循此 tip 后，我能够测试 SherlockFragmentActivity ，但是当我将这个 fragment (即 SherlockFragment)添加到我的 Activity xml 时:

<fragment 
    android:name="com.marcelopazzo.fragmentapplication.ExampleFragment" 
    android:id="@+id/example_fragment"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" />

SherlockFragment 类:

public class ExampleFragment extends SherlockFragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.example_fragment, container, false);
    }
}

这是被 fragment 膨胀的布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/hello_again"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_again" />

</LinearLayout>

我收到以下错误:

java.lang.NullPointerException
    at org.robolectric.shadows.ShadowViewGroup.addView(ShadowViewGroup.java:69)
    at android.view.ViewGroup.addView(ViewGroup.java)
    at org.robolectric.res.builder.LayoutBuilder.constructFragment(LayoutBuilder.java:150)
    at org.robolectric.res.builder.LayoutBuilder.create(LayoutBuilder.java:104)
    at org.robolectric.res.builder.LayoutBuilder.doInflate(LayoutBuilder.java:42)
    at org.robolectric.res.builder.LayoutBuilder.doInflate(LayoutBuilder.java:45)
    at org.robolectric.res.builder.LayoutBuilder.inflateView(LayoutBuilder.java:62)
    at org.robolectric.shadows.ShadowLayoutInflater.inflate(ShadowLayoutInflater.java:50)
    at org.robolectric.shadows.ShadowLayoutInflater.inflate(ShadowLayoutInflater.java:55)
    at android.view.LayoutInflater.inflate(LayoutInflater.java)
    at com.squareup.test.ActionBarSherlockRobolectric.setContentView(ActionBarSherlockRobolectric.java:38)
    at com.actionbarsherlock.app.SherlockFragmentActivity.setContentView(SherlockFragmentActivity.java:262)
    at com.marcelopazzo.fragmentapplication.MainActivity.onCreate(MainActivity.java:13)
    at com.marcelopazzo.fragmentapplication.MainActivityTest.setUp(MainActivityTest.java:33)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
    at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:110)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:234)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:133)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:114)
    at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:188)
    at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:166)
    at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:86)
    at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:101)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:74)

这是我正在使用的测试类:

@RunWith(RobolectricTestRunner.class)
public class MainActivityTest {

    private MainActivity activity;
    private TextView textView;

    public static final String GREETINGS = "Hello world!";  

    @Before
    public void setUp() {

        ActionBarSherlock.registerImplementation(ActionBarSherlockRobolectric.class);
        ActionBarSherlock.unregisterImplementation(ActionBarSherlockNative.class);
        ActionBarSherlock.unregisterImplementation(ActionBarSherlockCompat.class);

        activity = new MainActivity();
        activity.onCreate(null);

        textView = (TextView) activity.findViewById(R.id.hello);
    }

    @Test
    public void shouldGreet() {
        assertEquals(GREETINGS, textView.getText());
    }
}

应用程序在设备上运行良好。

我在这里错过了什么？

ps:完整的源代码可以在github上找到。

编辑:还使用 square/master (2.0 alpha 3 square 5) 分支的代码进行了测试并遇到了同样的问题。检查 LayoutBuilder.constructFragment，我认为问题是 activity.getSupportFragmentManager().beginTransaction().add(fragment, tag).commit() 无法使用SherlockFragment，所以 fragment.getView() 返回 null。

我不确定我是否可以做任何事情来解决这个问题......我已经在检查我是否可以在 robolectric 方面修复它，如果有人对此有任何提示，请告诉我。

Answer 1

您可以尝试使用 Robolectric 2.0 的新 ActivityController，它修复了一些经常出现的调度/操作顺序问题。

MainActivity activity = Robolectric.buildActivity(MainActivity.class)
                                    .create().get();

它安排主循环程序在调用 onCreate() 期间暂时暂停。