Espresso 2.0 - Method annotated with @Test inside class extending junit3 testcase

Question

I got a weird warning Method annotated with @Test inside class extending junit3 testcase when using the new ActivityInstrumentationTestCase2 class shipped with Espresso 2.0.

My class looks just like the one that Google provided as an example:

import android.support.test.InstrumentationRegistry;
import android.support.test.runner.AndroidJUnit4;
import android.test.ActivityInstrumentationTestCase2;
import android.test.suitebuilder.annotation.LargeTest;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import static android.support.test.espresso.matcher.ViewMatchers.assertThat;
import static org.hamcrest.Matchers.notNullValue;

@RunWith(AndroidJUnit4.class)
@LargeTest
public class MyCoolActivityTests extends ActivityInstrumentationTestCase2<MyCoolActivity> {

    private MyCoolActivity mActivity;

    public MyCoolActivityTests() {
        super(MyCoolActivity.class);
    }

    @Before
    public void setUp() throws Exception {
        super.setUp();
        injectInstrumentation(InstrumentationRegistry.getInstrumentation());
        mActivity = getActivity();
    }

    @Test
    public void checkPreconditions() {
        assertThat(mActivity, notNullValue());
        // Check that Instrumentation was correctly injected in setUp()
        assertThat(getInstrumentation(), notNullValue());
    }

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

I've added all necessary things to the build.gradle:

android {
    defaultConfig {
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
}

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

Is there any way to get this warning away?

Answer 1

ActivityInstrumentationTestCase2 is a JUnit 3 test case because it extends from TestCase .

@Test annotation is a replacement for the test-prefix naming convention used in JUnit 3. JUnit 4 test classes no longer require to extend TestCase or any of its subclasses. In fact JUnit 4 tests cannot extend TestCase, otherwise AndroidJUnitRunner will treat them as JUnit 3 tests.

http://developer.android.com/tools/testing-support-library/index.html#AndroidJUnitRunner

You could either migrate to ActivityTestRule provided by com.android.support.test:rules:0.4 (or later), or stick with JUnit 3.

Another option is InstrumentationRegistry , provided by Espresso 2, which has getInstrumentation() , getContext() , getTargetContext() (and more). These methods provide access to the current instrumentation, test context, and target context in a static manner. This makes it possible to write your own static utility methods for use in JUnit 4 test case classes. These utilities would mimic functionality that is currently only available in the base JUnit 3 test case classes. (This is no longer necessary.)