Android Studio running unit test shows 'Empty test suite'

Question

I want to start writing unit tests for my applications but I cannot get one simple test to run. I have created a small application just to try how the unit test should be setup and run, but no test is actually run and I get 'Empty test suite'.

I am using Android Studio 0.6.1 with gradle 1.12

Here is my folder structure:

MyActivityTest.java

package com.vist.testableapp.tests;

import android.content.Intent;
import android.test.ActivityUnitTestCase;
import android.test.suitebuilder.annotation.SmallTest;
import android.widget.Button;

import com.vist.testableapp.MyActivity;
import com.vist.testableapp.R;

public class MyActivityTest extends ActivityUnitTestCase<MyActivity>
{
    public MyActivityTest(Class<MyActivity> activityClass)
    {
        super(activityClass);
    }
    Button btn1;

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

        startActivity(new Intent(getInstrumentation().getTargetContext(), MyActivity.class), null, null);
        btn1 = (Button)getActivity().findViewById(R.id.button1);
    }

    @SmallTest
    public void testFirst()
    {
        assertEquals("Btn1",btn1.getText());
    }
}

application's build.gradle

apply plugin: 'android'

android {
    compileSdkVersion 19
    buildToolsVersion "19.1.0"

    defaultConfig {
        applicationId "com.vist.testableapp"
        minSdkVersion 15
        targetSdkVersion 15
        versionCode 1
        versionName "1.0"
        testApplicationId "com.vist.testableapp.tests"

    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
}

Could anyone point out what am I doing wrong or what I am missing? I searched in SO but none of the answers helped me.

Answer 1

The constructor should look like this:

public MyActivityTest()
{
    super(MyActivity.class);
}

I will need to learn not to rely so much on the IDE's code template that provided constructor with parameter. This was resolved thanks to a colleague and http://siemprepreguntando.blogspot.de/2013/07/running-tests-test-running-startedtest.html

Answer 2

I also ran into "empty test suite" problem recently. After checking a few similar questions and answers, and my problem, I can possibly conclude that the problem results from an error preventing the tests being added to the test suite, such as an error in static initialization.

For example I'm using a popular approach to adding all tests as shown below, but it's the same scenario with different approaches to adding test cases to the suite:

public class FullTestSuite extends TestSuite {
public static Test suite() {
    return new TestSuiteBuilder(FullTestSuite.class)
            .includeAllPackagesUnderHere().build();
}

public FullTestSuite() {
    super();
}
}

And apparently my test file had a problem in a static {} block which prevented .includeAllPackagesUnderHere() to run successfully.

So I would suggest anyone facing this error to first check your app logs to see if your test runs into a problem that prevents test cases being added to the test suite (like similar examples of wrong constructor being called or static initialization problems).

Answer 3

In my case, the "empty test suite" message was directly related to the target API Level of the Android Emulator I was running. I had set up an emulator with API level 19 and was using that while trying to run my instrumentation tests. I also had just recently migrated my codebase to use the JUnit4 framework along with the AndroidJUnitRunner instrumentation runner.

I was banging my head against the wall for a while before I started to look into issues with the actual emulator. Sure enough, as soon as I set up an emulator with API Level 23, the tests started to run fine.

Further experimentation found that my tests ran fine on API Level 22 & 23 emulators, but not on anything below that. I suspect it has something to do with my test dependencies and minimum API level requirements.

I'll update this answer if I discover more.