How to test Application class with Robolectric?

Question

I am trying to test push notification with Parse.com using Robolectric. As the initialization has to be done in an Application class, I need to test it. So far, the app is working fine on emulator but I am not able to test it with Robolectric.

My onCreate of application class:

public void onCreate() {
            super.onCreate();

            // Add your initialization code here
            Parse.initialize(this, APP_KEY,
                            CLIENT_ID);

            // Specify an Activity to handle all pushes by default.
            PushService.setDefaultPushCallback(this, MainActivity.class);

            // Save the current Installation to Parse.
            //This is null on test
            android_id = Secure.getString(getApplicationContext()
                            .getContentResolver(), Secure.ANDROID_ID);

            System.out.println("android id >>" + android_id);

            ParseInstallation installation = ParseInstallation
                            .getCurrentInstallation();
            installation.put("UniqueId", android_id);
            installation.saveInBackground();

            ParseUser.enableAutomaticUser();
            ParseACL defaultACL = new ParseACL();

            // If you would like all objects to be private by default, remove this
            // line.
            defaultACL.setPublicReadAccess(true);
            Parse.setLogLevel(Parse.LOG_LEVEL_VERBOSE);
            ParseACL.setDefaultACL(defaultACL, true);
    }

Test

@RunWith(RobolectricTestRunner.class)
public class TestParseApplication extends Application {
private ParseApplication parseApplication;

@Before
public void setup() {

    parseApplication = new ParseApplication();
    parseApplication.android_id = "123";

    Robolectric.application = parseApplication;
}

@Test
public void shouldPass() {
    assertTrue(true);
}

}

StackTrace

WARNING: no system properties value for ro.build.date.utc
android id >>null

java.lang.IllegalArgumentException: Must subscribe to channel with a valid icon identifier.
        at com.parse.PushService.setDefaultPushCallback(PushService.java:298)
        at com.parse.PushService.setDefaultPushCallback(PushService.java:277)
        at com.parse.starter.ParseApplication.onCreate(ParseApplication.java:30)
        at org.robolectric.internal.ParallelUniverse.setUpApplicationState(ParallelUniverse.java:164)
        at org.robolectric.RobolectricTestRunner.setUpApplicationState(RobolectricTestRunner.java:430)
        at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:236)
        at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
        at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
        at org.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:177)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
        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)

Answer 1

You should wrap Parse API to some class and mock it:

public class ParseAPI {
   public void init(Context context, String key, String id) {
        // Add your initialization code here
        Parse.initialize(context, key,
                        id);
   }

   public void initPush(Context context, Class pushCallbackClass) {
        // Specify an Activity to handle all pushes by default.
        PushService.setDefaultPushCallback(context, puchCallbackClass);
   }
}

Modify your app:

public void onCreate() {
    super.onCreate();

    ParseAPI api = getParseAPI();

    api.init(this, APP_KEY, CLIENT_ID)
    api.initPush(this, MainActivity.class);
}

protected ParseAPI getParseAPI() {
    return new ParseAPI();
}

Modify your test app and tests:

@RunWith(RobolectricTestRunner.class)
public class TestParseApplication extends ParseApplication {
private ParseApplication parseApplication;

@Before
public void setup() {

    parseApplication = new TestParseApplication();
    parseApplication.android_id = "123";

    Robolectric.application = parseApplication;
}

protected ParseAPI getParseAPI() {
    return new ParseAPI() {
               public void init(Context context, String key, String id) {
               }

               public void initPush(Context context, Class pushCallbackClass) {
               }
    };
}

@Test
public void shouldPass() {
    assertTrue(true);
}

}

This should work if I don't make any error while typing.

Of course this is rough idea. It is better to use some mock library instead of writing anonymous classes in tests (My favourite is Mockito ). Please also read about dependency inversion and injection ( IoC ). And last it is much better to separate Robolectric test application from application tests (please read http://robolectric.blogspot.nl/2013/04/the-test-lifecycle-in-20.html )

Answer 2

public class TestParseApplication extends Application

This should be a test set or a test suite, not the actual class you are testing.

For each test, you need to instantiate the Application class. Actually, Robolectric does that for you if you have properly declared Application class in your manifest, and you can get current application instance (with enhanced testing facilities) from robolectric api: getShadowApplication().