Android Studio - test configuration starts up app

Issue

I've got a couple of AndroidTestCase subclasses in separate packages of my project:

However, whenever I run Android Tests configuration from Android Studio, I see that my regular app is starting as well. I see that the onCreate method is fired up inside my Application class (which is really bad since I am loading some additional resources there).
Why is Android Studio/gradle running my app as well?
Can I programatically detect if I am inside test or regular configuration?
Can I stop my regular app from being booted before running tests?
In addition, when I am running tests in debug mode it doesn't stop on breakpoints placed inside the application's onCreate method. Why is this happening?

Edit:
Body of test class doesn't really matter, it can be something like:

public class SimpleTest extends AndroidTestCase {
    public void testSample()
    {
        assertEquals(true, false);
    }
}

Executing only this simple test fires up onCreate method inside application class. Gradle console prints out:

Executing tasks: [:app:assembleDebug, :app:assembleDebugTest]

I guess that first task creates instance of my Application class - is it expected behavior?

Solution

Why is Android Studio/gradle running my app as well?

Can I stop my regular app from being booted before running tests?

AndroidTestCase is extension of JUnit TestCase which is aware of your android application. In case you don't need to test your android application and want to test plain java only you should use JUnit framework. Create regular JUnit tests, do not use android classes there and run JUnit test configuration like this:

You should treat AndroidTestCase as instrumentation tests which will build android app and run that tests on it. This is usefull with combination of Espresso and Robotium. Both are working on top of base android test classes and both will build and run your application before testing it. Real device or emulator is needed.

Use plain JUnit tests or Robolectric to test java on your desktop JVM.

Can I programatically detect if I am inside test or regular configuration?

You can use power of gradle to provide such info with autogenerated BuildConfig file.

At your build.gradle

android {
    defaultConfig {
        testPackageName "com.foo.test"
    }
}

At your code:

BuildConfig.PACKAGE_NAME.equals("com.foo.test")

Answered By - Sergii Pechenizkyi