Java 使用instrumentation和JUnit4测试重新创建Android活动

我想为重新创建活动编写测试。执行旋转是可选的

我希望测试是用谷歌“祝福”的测试框架的最新版本编写的。我不熟悉编写测试，所以我想学习基本的、主流的、支持良好的工具。只要我掌握了基本知识，任何第三方测试框架都可以。既然我想测试非常基本的，经常发生的场景，基本的工具就足够了，对吗

最小测试代码：

public class MainActivity extends AppCompatActivity {

    static int creationCounter = 0;
    Integer instanceId;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ++creationCounter;
        instanceId = new Integer(creationCounter);
        Log.d("TEST", "creating activity " + this + ", has id " + instanceId);
    }
}

测试级别：

@RunWith(AndroidJUnit4.class)
public class ExampleInstrumentedTest {

    @Rule
    public ActivityTestRule<MainActivity> mActivityTestRule = new ActivityTestRule<>(MainActivity.class);

    @Test
    public void useAppContext() throws Exception {

        MainActivity activity1 = mActivityTestRule.getActivity();
        int act1 = activity1.instanceId.intValue();
        int counter1 = MainActivity.creationCounter;
        assertEquals(1, counter1);
        assertEquals(1, act1);


        Log.d("TEST", "requesting rotation");
        // method 1
         activity1.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        // method 2 //https://gist.github.com/nbarraille/03e8910dc1d415ed9740#file-orientationchangeaction-java
        // onView(isRoot()).perform(orientationLandscape());

        getInstrumentation().waitForIdleSync(); // I thought this should suffice
        // How to do this?
        //somehowRefreshActivityInstanceInsideTestRule();

        MainActivity activity2 = mActivityTestRule.getActivity();
        int act2 = activity2.instanceId.intValue();
        int counter2 = MainActivity.creationCounter;
        Log.d("TEST", "newly acquired activity " + activity2 + " has id " + act2 + "/" + counter2);

        assertEquals(2, counter2);
        assertEquals(2, act2);
    }
}

但我不知道如何把它翻译成新版本

编辑：

上述两种方法都使活动处于销毁状态：assertFalse（mactivityTesture.getActivity（）.isDestroyed（））；失败了

---

我找到了另一个方法（），它重新创建活动实例，但不通过onSaveInstanceState保持其状态

我终于在这里找到了有效的解决方案：

在适应我的需要后，代码如下所示：

public class CurrentActivityTestRule<T extends Activity> extends ActivityTestRule<T> {
    public CurrentActivityTestRule(Class<T> activityClass) {
        super(activityClass, false);
    }

    public CurrentActivityTestRule(Class<T> activityClass, boolean initialTouchMode) {
        super(activityClass, initialTouchMode, true);
    }

    public CurrentActivityTestRule(Class<T> activityClass, boolean initialTouchMode, boolean launchActivity) {
        super(activityClass, initialTouchMode, launchActivity);
    }

    public T getCurrentActivity() {
        getInstrumentation().waitForIdleSync();
        final Activity[] activity = new Activity[1];
        getInstrumentation().runOnMainSync(new Runnable() {
            @Override
            public void run() {
                java.util.Collection<Activity> activities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(Stage.RESUMED);
                activity[0] = Iterables.getOnlyElement(activities);
            }});
        T current = (T) activity[0];
        return current;
    }
}

onView(isRoot()).perform(orientationLandscape());
Activity oldActivityInstance = mActivityTestRule.getActivity();
Activity currentActivityInstance = mActivityTestRule.getCurrentActivity();

我在使用库版本时遇到了以下问题：

androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
androidTestCompile('com.android.support.test:runner:0.5', {
    exclude group: 'com.android.support', module: 'support-annotations'
})

---

当前版本的

android.test.rule

解决了这个问题。

---

在调用

activityTestRule.getActivity（）

@MateuszL的解决方案现在仍然可以与androidx测试编排器和Kotlin一起使用，以防此版本对任何人都有帮助：

import androidx.test.espresso.core.internal.deps.guava.collect.Iterables
import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
import androidx.test.rule.ActivityTestRule
import androidx.test.runner.lifecycle.ActivityLifecycleMonitorRegistry
import androidx.test.runner.lifecycle.Stage

class CurrentActivityTestRule<T : Activity> : ActivityTestRule<T> {

    val currentActivity: T
        get() {
            getInstrumentation().waitForIdleSync()
            val activity = arrayOfNulls<Activity>(1)
            getInstrumentation().runOnMainSync(Runnable {
                val activities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(Stage.RESUMED)
                activity[0] = Iterables.getOnlyElement(activities)
            })
            @Suppress("UNCHECKED_CAST")
            return activity[0] as T
        }

    constructor(activityClass: Class<T>) : super(activityClass, false)

    constructor(activityClass: Class<T>, initialTouchMode: Boolean) : super(activityClass, initialTouchMode, true)

    constructor(activityClass: Class<T>, initialTouchMode: Boolean, launchActivity: Boolean) : super(
        activityClass,
        initialTouchMode,
        launchActivity
    )
}

---

ActivityTestRule.getActivity不会创建新的活动，只是为您提供相同的实例。我知道这不起作用。我想知道如何使其工作，而不一定使用ActivityTestRule这仍然适用于androidx和androidx测试编排器，以及Kotlin。添加答案以防对任何人都有帮助，并引用您的答案作为来源。

androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
androidTestCompile('com.android.support.test:runner:0.5', {
    exclude group: 'com.android.support', module: 'support-annotations'
})

import androidx.test.espresso.core.internal.deps.guava.collect.Iterables
import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
import androidx.test.rule.ActivityTestRule
import androidx.test.runner.lifecycle.ActivityLifecycleMonitorRegistry
import androidx.test.runner.lifecycle.Stage

class CurrentActivityTestRule<T : Activity> : ActivityTestRule<T> {

    val currentActivity: T
        get() {
            getInstrumentation().waitForIdleSync()
            val activity = arrayOfNulls<Activity>(1)
            getInstrumentation().runOnMainSync(Runnable {
                val activities = ActivityLifecycleMonitorRegistry.getInstance().getActivitiesInStage(Stage.RESUMED)
                activity[0] = Iterables.getOnlyElement(activities)
            })
            @Suppress("UNCHECKED_CAST")
            return activity[0] as T
        }

    constructor(activityClass: Class<T>) : super(activityClass, false)

    constructor(activityClass: Class<T>, initialTouchMode: Boolean) : super(activityClass, initialTouchMode, true)

    constructor(activityClass: Class<T>, initialTouchMode: Boolean, launchActivity: Boolean) : super(
        activityClass,
        initialTouchMode,
        launchActivity
    )
}

@Suppress("CAST_NEVER_SUCCEEDS")
private fun getRegistrationActivity()= activityTestRule.currentActivity as RegistrationActivity