I configured Robolectric as on their website:

android {
  testOptions {
    unitTests {
      includeAndroidResources = true
    }
  }
}

dependencies {
  testImplementation 'junit:junit:4.13.2'
  testImplementation 'org.robolectric:robolectric:4.12.2'
}

And created my first test:

@RunWith(RobolectricTestRunner.class)
public class MyTest {
    @Test
    public void testMethod() {
        try(ActivityController<MyActivity> controller = Robolectric.buildActivity(MyActivity.class)) {
            controller.setup();
        }
    }
}

However, when running the test, it gives an error at buildActivity:

java.lang.RuntimeException: Method getMainLooper in android.os.Looper not mocked. See https://developer.android.com/r/studio-ui/build/not-mocked for details.

The corresponding site says that adding returnDefaultValues = true fixes it:

android {
  ...
  testOptions {
    unitTests.returnDefaultValues = true
  }

And that’s also true. But then I get another error:

java.lang.NullPointerException: Cannot invoke “android.os.Looper.getThread()” because the return value of “android.os.Looper.getMainLooper()” is null

So I think there is a more deeper problem as to why Robolectric doesn’t work. The error makes sense, as probably the default return value is null. But I have no other idea on how to fix it.

Does anybody know as to why Robolectric doesn’t run?