Android JUnitRunner Empty Test Suite: No Test Results

Issue

I'm having trouble running tests in Android Studio. I've read through a load of posts with the same problem here on Stack Overflow, but to no avail. Just to be clear, I want to test in the emulator and not in the JVM.

Run configuration:

Output:

Running tests
Test running startedTest running failed: No test results
Empty test suite.

Build.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.0"

    defaultConfig {
        applicationId "ntnu.stud.markul.crowdshelf"
        minSdkVersion 19
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.0.1'
    // Unit testing dependencies
    androidTestCompile ('com.android.support.test:rules:0.3') {
        exclude group: 'com.android.support', module: 'support-annotations'
    }
    androidTestCompile('com.android.support.test:runner:0.3') {
        // Necessary if your app targets Marshmallow (since the test runner
        // hasn't moved to Marshmallow yet)
        exclude group: 'com.android.support', module: 'support-annotations'
    }
    androidTestCompile 'junit:junit:4.12'
    testCompile 'junit:junit:4.12'
}

The test class (located in /src/androidTest/java/com/appname/app/):

@RunWith(AndroidJUnit4.class)
public class NetworkAndDBInstrumentationTest extends ActivityInstrumentationTestCase2<MainActivity> {
    private MainActivity mActivity;
    public NetworkAndDBInstrumentationTest() {
        super(MainActivity.class);
    }

    @Before
    public void setUp() throws Exception {
        super.setUp();

        // Injecting the Instrumentation instance is required
        // for your test to run with AndroidJUnitRunner.
        injectInstrumentation(InstrumentationRegistry.getInstrumentation());
        mActivity = getActivity();
    }

    @Test
    public void typeOperandsAndPerformAddOperation() {
        NetworkController.getCrowd("55f01f29f0a5fad2120bb1db");
        System.out.print("ok");
        Log.d("1TEST", "1TEST");
    }

    @After
    public void tearDown() throws Exception {
        super.tearDown();
    }
}

Solution

I got it to work using this:

@RunWith(AndroidJUnit4.class)
@LargeTest
public class NetworkAndDBInstrumentationTest {
    //use the following annotation and declare an ActivityTestRule for your activity under test
    @Rule
    public ActivityTestRule<RealmActivity> mActivityRule = new ActivityTestRule(RealmActivity.class);

    //use @Before to setup your test fixture
    @Before
    public void setUp() {  }

    //annotate all test methods with
    @Test
    public void testGetCrowd() {
        Assert.assertEquals(1, 1);
    }
    @After
    public void tearDown() {  }
}

Where RealmActivity is the Activity I want to test. Build.gradle and everything else is as in the question post. Now, a follow-up question: What does it matter that I make the @Rule with RealmActivity? Can't I use other Activities in that test? Can I make a Activity-independent test?

Answered By - tsorn