A test that finds all of my app's Activitys and then ensures the tracking annotation @ScreenView exists. Friendly error message when you miss one.

TestActivityAnalytics.java

package com.brantapps.oceanlife.activity;

import android.app.Activity;

import com.brantapps.oceanlife.analytics.aop.ScreenView;
import com.brantapps.oceanlife.analytics.event.Tags;
import com.brantapps.oceanlife.domain.activity.SplashActivity;
import com.brantapps.oceanlife.preference.activity.AboutActivity;
import com.brantapps.oceanlife.preference.activity.ApplicationPreferencesActivity;
import com.brantapps.oceanlife.preference.activity.DisclaimerActivity;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import com.google.common.reflect.ClassPath;

import org.apache.commons.lang3.StringUtils;
import org.junit.Test;

import java.io.IOException;
import java.lang.reflect.Modifier;
import java.util.Set;

import static org.hamcrest.core.Is.is;
import static org.hamcrest.core.IsEqual.equalTo;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;

/**
 * Test to ensure that subclasses of {@link android.app.Activity}
 * are annotated with the correct analytics tracking events & properties.
 *
 * Created by david.branton on 18/07/2017.
 */
public class TestActivityAnalytics {

  /**
   * Check that each of the sub-classes of activity override the
   * {@linkplain Activity#onResume()} method and have annotated it
   * with the {@link com.brantapps.oceanlife.analytics.aop.ScreenView}
   * tag.
   */
  @Test
  public void haveScreenViewAnnotationOnResume() throws IOException {
    // Given - load the classes on the classpath.
    final ClassPath classPath = ClassPath.from(ClassLoader.getSystemClassLoader());

    // When - a class that subclasses Activity (that isn't abstract) is found...
    final Set<Class<?>> concreteActivities = Sets.newHashSet();
    for (ClassPath.ClassInfo classInfo : classPath.getTopLevelClassesRecursive("com.brantapps.oceanlife")) {
      final Class clazz = classInfo.load();
      if (Activity.class.isAssignableFrom(clazz) && !Modifier.isAbstract(clazz.getModifiers())) {
        concreteActivities.add(clazz);
      }
    }

    // Then - find the onResume() method and check the method is annotated.
    concreteActivities.stream().allMatch(input -> {
      try {
        final ScreenView[] screenViewAnnotations = input.getDeclaredMethod("onResume").getAnnotationsByType(ScreenView.class);
        assertThat(screenViewAnnotations.length, is(equalTo(1)));
        assertThat(screenViewAnnotations[0].screenName(), is(equalTo(activityToCurrentScreenParameter.get(input.getName()))));
        assertThat(screenViewAnnotations[0].screenClassOverride(), is(equalTo(StringUtils.EMPTY)));
        return true;
      } catch (NoSuchMethodException e) {
        fail(String.format("Missing onResume screen view tracking for activity [%s]", input.getSimpleName()));
        return false;
      }
    });
  }


  private ImmutableMap<String, String> activityToCurrentScreenParameter = ImmutableMap.<String, String>builder()
      .put(AboutActivity.class.getName(), Tags.ScreenView.ABOUT)
      .put(AddSpotActivity.class.getName(), Tags.ScreenView.ADD_SPOT)
      .put(DisclaimerActivity.class.getName(), Tags.ScreenView.DISCLAIMER)
      .put(SplashActivity.class.getName(), Tags.ScreenView.SPLASH)
      .put(SpotDetailActivity.class.getName(), Tags.ScreenView.SPOT_DETAIL)
      .put(SpotListActivity.class.getName(), Tags.ScreenView.SPOT_LIST)
      .put(ApplicationPreferencesActivity.class.getName(), Tags.ScreenView.PREFERENCES)
    .build();
}