我正在使用自定义 FragmentTestRule 和 Espresso 来单独测试我的每个 Fragments。
我有一个专用的TestActivity,它在我的应用程序中显示经过测试的Fragments。在我的情况下,Activity 仅存在于debug 变体中,因为我的仪器测试针对debug 运行。
TL;DR 使用 @brais-gabin 提供的很棒的 FragmentTestRule 库。
1.在 src/debug/java/your/package/TestActivity.java 中创建一个 TestActivity,并在其中添加测试的 Fragment 的内容视图:
@VisibleForTesting
public class TestActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FrameLayout frameLayout = new FrameLayout(this);
frameLayout.setId(R.id.container);
setContentView(frameLayout);
}
}
2。为debug 变体创建一个AndroidManifest.xml 并声明TestActivity。这是在测试时启动TestActivity 所必需的。将此 Manifest 添加到 src/debug/AndroidManifest.xml 中的 debug 变体中:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<application>
<activity android:name="your.package.TestActivity"/>
</application>
</manifest>
3.在androidTest 变体src/androidTest/java/your/test/package/FragmentTestRule.java 中创建FragmentTestRule:
public class FragmentTestRule<F extends Fragment> extends ActivityTestRule<TestActivity> {
private final Class<F> mFragmentClass;
private F mFragment;
public FragmentTestRule(final Class<F> fragmentClass) {
super(TestActivity.class, true, false);
mFragmentClass = fragmentClass;
}
@Override
protected void afterActivityLaunched() {
super.afterActivityLaunched();
getActivity().runOnUiThread(() -> {
try {
//Instantiate and insert the fragment into the container layout
FragmentManager manager = getActivity().getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
mFragment = mFragmentClass.newInstance();
transaction.replace(R.id.container, mFragment);
transaction.commit();
} catch (InstantiationException | IllegalAccessException e) {
Assert.fail(String.format("%s: Could not insert %s into TestActivity: %s",
getClass().getSimpleName(),
mFragmentClass.getSimpleName(),
e.getMessage()));
}
});
}
public F getFragment(){
return mFragment;
}
}
4.然后你可以单独测试Fragments:
public class MyFragmentTest {
@Rule
public FragmentTestRule<MyFragment> mFragmentTestRule = new FragmentTestRule<>(MyFragment.class);
@Test
public void fragment_can_be_instantiated() {
// Launch the activity to make the fragment visible
mFragmentTestRule.launchActivity(null);
// Then use Espresso to test the Fragment
onView(withId(R.id.an_id_in_the_fragment)).check(matches(isDisplayed()));
}
}