Some Noob Student Some Noob Student - 1 month ago 12
Android Question

ActivityUnitTestCase throws RuntimeException when ran with AndroidJUnitRunner

I am trying to integrate Espresso 2.0's AndoridJUnitRunner with ActivityUnitTestCase. However, my tests are crashing when startActivity() tries to initialize mMockParent = new MockParent().

Here's what I did:

Create a new project with Intellij 14 CE and make some changes to build.gradle.

android{
defaultConfig {
applicationId "com.noob.testing"
minSdkVersion 9
targetSdkVersion 21
versionCode 1
versionName "1.0"

testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_7
targetCompatibility JavaVersion.VERSION_1_7
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:21.0.+'

androidTestCompile('org.mockito:mockito-core:1.9.5')
androidTestCompile('com.google.dexmaker:dexmaker:1.2')
androidTestCompile('com.google.dexmaker:dexmaker-mockito:1.2')

androidTestCompile('com.android.support.test.espresso:espresso-core:2.0')
androidTestCompile('com.android.support.test:testing-support-lib:0.1')
}


Write a JUnit4-style unit test.

@RunWith(AndroidJUnit4.class)
public class MainActivityJUnit4Test extends ActivityUnitTestCase<MainActivity> {
public MainActivityJUnit4Test() {
super(MainActivity.class);
}

MainActivity activity;

@Before
public void setup() throws Exception {
injectInstrumentation(InstrumentationRegistry.getInstrumentation());
super.setUp();
ContextThemeWrapper context = new ContextThemeWrapper(getInstrumentation().getTargetContext(), R.style.AppTheme);
setActivityContext(context);
activity = startActivity(new Intent(Intent.ACTION_MAIN), null, null);
}

@Test
public void baseCase() {
TextView tv = (TextView) activity.findViewById(R.id.tv);
Assert.assertEquals("Hello World", tv.getText());

}
}


Run the test, getting a stack trace.

junit.framework.AssertionFailedError
at junit.framework.Assert.fail(Assert.java:48)
at junit.framework.Assert.assertTrue(Assert.java:20)
at junit.framework.Assert.assertNotNull(Assert.java:218)
at junit.framework.Assert.assertNotNull(Assert.java:211)
at android.test.ActivityUnitTestCase.startActivity(ActivityUnitTestCase.java:147)
at com.sdchang.testing.MainActivityJUnit4Test.setup(MainActivityJUnit4Test.java:32)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
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.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:24)
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$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:270)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)


This stack trace is actually a rethrow of

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()


that occurs when startActivity() tries to initialize mMockParent = new MockParent():

ComponentName cn = new ComponentName(mActivityClass.getPackage().getName(),
mActivityClass.getName());
intent.setComponent(cn);
ActivityInfo info = new ActivityInfo();
CharSequence title = mActivityClass.getName();
mMockParent = new MockParent();
String id = null;


Am I missing anything else to get AndroidJUnitRunner working with ActivityUnitTestCase? Any help would be greatly appreciated.

Answer

After banging my head against the wall, windows and various furniture, I finally got my tests working!

From a response on its issue tracker, I learned that no new Handlers can be created from the instrumentation thread. Which means startActivity() must be invoked in the UI thread. Which leads to 3 solutions.

1.Use Instrumentation's runOnMainSync()

getInstrumentation().runOnMainSync(new Runnable() {
    @Override
    public void run() {
        activity = startActivity(new Intent(Intent.ACTION_MAIN), null, null);
    }
});

2.Create your own base class that extends ActivityUnitTestCase and override startActivity

@Override
protected T startActivity(final Intent intent, final Bundle savedInstanceState,
        final Object lastNonConfigurationInstance) {
    return startActivityOnMainThread(intent, savedInstanceState, lastNonConfigurationInstance);
}

private T startActivityOnMainThread(final Intent intent, final Bundle savedInstanceState,
        final Object lastNonConfigurationInstance) {
    final AtomicReference<T> activityRef = new AtomicReference<>();
    final Runnable activityRunnable = new Runnable() {
        @Override
        public void run() {
            activityRef.set(YourBaseActivityUnitTestCase.super.startActivity(
                    intent, savedInstanceState, lastNonConfigurationInstance));
        }
    };

    if (Looper.myLooper() != Looper.getMainLooper()) {
        getInstrumentation().runOnMainSync(activityRunnable);
    } else {
        activityRunnable.run();
    }

    return activityRef.get();
}

3.If you call startActivity() in a test method and your entire test can run on the main thread, you can simply annotate your test method with @UiThreadTest.

In my testing, I've tried all 3 solutions, but only 1 & 2 will work.

Comments