使用 Robolectric ClassCastException 进行 Android 测试：android.app.Application 无法转换为 MyApplication

Question

我正在用 Robolectric 测试我的 android 应用程序，但我正在努力解决这个问题：

 MyModel myModel = ((MyApplication) context.getApplicationContext()).getMyModel;

显然 Robolectric 抱怨这个错误：

 java.lang.RuntimeException: java.lang.ClassCastException: android.app.Application cannot be cast to com.reply.delhaize.common.DelhaizeApplication
    at org.robolectric.util.SimpleFuture.run(SimpleFuture.java:57)
    at org.robolectric.shadows.ShadowAsyncTask$2.run(ShadowAsyncTask.java:95)
    at org.robolectric.util.Scheduler.postDelayed(Scheduler.java:37)
    at org.robolectric.util.Scheduler.post(Scheduler.java:42)
    at org.robolectric.shadows.ShadowAsyncTask.execute(ShadowAsyncTask.java:92)
    at android.os.AsyncTask.execute(AsyncTask.java)
    at com.reply.delhaize.common.models.StoreModel.getStoreList(StoreModel.java:617)
    at com.reply.delhaize.common.models.StoreModel.fetchAllStores(StoreModel.java:107)
    at com.reply.delhaize.core.tests.storefinder.StoreFinderTest.fetchAllStoresWhenWifiIsOn(StoreFinderTest.java:84)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:234)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:175)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to com.reply.delhaize.common.DelhaizeApplication
    at com.my.package.name.models.GetApiModelTaskOtto.doInBackground(GetApiModelTaskOtto.java:74)
    at com.my.package.name.models.GetApiModelTaskOtto.doInBackground(GetApiModelTaskOtto.java:1)
    at android.os.ShadowAsyncTaskBridge.doInBackground(ShadowAsyncTaskBridge.java:14)
    at org.robolectric.shadows.ShadowAsyncTask$BackgroundWorker.call(ShadowAsyncTask.java:149)
    at org.robolectric.util.SimpleFuture.run(SimpleFuture.java:52)
    at org.robolectric.shadows.ShadowAsyncTask$2.run(ShadowAsyncTask.java:95)
    at org.robolectric.util.Scheduler.postDelayed(Scheduler.java:37)
    at org.robolectric.util.Scheduler.post(Scheduler.java:42)
    at org.robolectric.shadows.ShadowAsyncTask.execute(ShadowAsyncTask.java:92)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.robolectric.bytecode.ShadowWrangler$ShadowMethodPlan.run(ShadowWrangler.java:456)
    at android.os.AsyncTask.execute(AsyncTask.java)
    at com.my.package.name.models.StoreModel.getStoreList(StoreModel.java:617)
    at com.my.package.name.models.StoreModel.fetchAllStores(StoreModel.java:107)
    at com.reply.delhaize.core.tests.storefinder.StoreFinderTest.fetchAllStoresWhenWifiIsOn(StoreFinderTest.java:84)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    ... 22 more

我想找到一种适当的方法来测试它。

我已经在清单中声明了 MyApplication：

   <application
    android:name="com.my.package.name.MyApplication"
    android:allowBackup="false"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    ......

这些是测试

        @RunWith(RoboletricTestRunner.class)
        public class StoreFinderTest extends BaseTest {


    StoreListActivity storeListActivity;
    StoreModel storeModel;
    UserModel userModel;

 @Before
public void setUp() throws Exception {

    storeListActivity = Robolectric.buildActivity(StoreListActivity.class).get();
    storeModel = new StoreModel(storeListActivity.getApplicationContext());
    userModel = new UserModel(storeListActivity.getApplicationContext());

}

@Test
public void activityExists() {

     assertThat(storeListActivity).isNotNull();
}


   @Test
public void fetchAllStoresWhenWifiIsOn() {      

ConnectivityManager cm =(ConnectivityManager)Robolectric.application.getSystemService(Context.CONNECTIVITY_SERVICE);

    Robolectric.shadowOf(cm).setNetworkInfo(ConnectivityManager.TYPE_WIFI, cm.getActiveNetworkInfo()); 

    boolean result = storeModel.fetchAllStores();
    assertTrue(result);
}

storeModel.fetchAllStores() 实现有这个丑陋的演员：

     MyModel myModel = ((MyApplication) context.getApplicationContext()).getMyModel;

那么有没有办法使用包含这样的强制转换的代码的 Robolectric 部分进行测试？

     ((MyApplication) context.getApplicationContext())

Answer 1

您可能需要为您的测试指定 AndroidManifest.xml 的路径。您可以使用以下方法执行此操作：

@Config(manifest = "/path/to/your/AndroidManifest.xml")
@RunWith(RoboletricTestRunner.class)
public class StoreFinderTest extends BaseTest {
...
}

您可以让 Robolectric 使用您的应用程序的测试版本，只需在项目的测试目录中与 MyApplication 相同的包中创建一个 TestMyApplication 类（即在您的应用程序类名称前带有前缀“Test”的类）。要解决您的转换问题，TestMyApplication 应该扩展 MyApplication：

public class TestMyApplication extends MyApplication {
}