Why can't I import AndroidJUnit4 and ActivityTestRule into my unit test class?

Question

I'm having trouble importing some of the Android UI testing framework classes - I just can't figure out what is going wrong!

This is my class:

@RunWith(AndroidJUnit4.class)
@LargeTest
public class ExampleUnitTest {

@Rule
public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule(MainActivity.class);

@Test
public void listGoesOverTheFold() {
    onView(withText("Hello world!")).check(matches(isDisplayed()));
  }
}

But for some reason I get the errors 'cannot find symbol ActivityTestRule' and 'cannot find symbol AndroidJUnit4'. I've tried to import them but they cannot be found.

The dependencies in build.gradle are set to:

compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.4.0'
androidTestCompile 'com.android.support:support-annotations:23.4.0'

androidTestCompile 'com.android.support.test:runner:0.4'
androidTestCompile 'com.android.support.test:rules:0.4'
androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1'
androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'

So I think I have all the dependencies setup - I've been trying many things but with no luck.

Anyone have any ideas?

Answer 1

There are two different types of tests you can set up in Android

Unit Tests

• These run directly on the JVM and do not have access to the Android framework classes.
• They are kept in the test/java package
• Dependencies need to added in the build.gradle file with the command testCompile
• You generally use Mockito, Robolectric & JUnit for these tests

Instrumentation Tests

• These run on an Android emulator and have full access to all the Android classes
• They are kept in the androidTest/java package
• Dependencies need to be added to build.gradle with androidTestCompile
• You generally use Espresso and JUnit for these tests

From what I can tell you are trying to write instrumentation tests with Espresso but have your test in the test/java package which is for unit tests. In that case you need to move your test class to the androidTest/java package.