javatests/dagger/hilt/android/ActivityInjectedSavedStateViewModelTest.java

/*
 * Copyright (C) 2021 The Dagger Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dagger.hilt.android;

import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
import static com.google.common.truth.Truth.assertThat;

import androidx.lifecycle.SavedStateHandle;
import androidx.lifecycle.ViewModel;
import androidx.lifecycle.ViewModelProvider;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import androidx.fragment.app.FragmentActivity;
import androidx.test.core.app.ActivityScenario;
import androidx.test.ext.junit.runners.AndroidJUnit4;
import dagger.Module;
import dagger.Provides;
import dagger.hilt.InstallIn;
import dagger.hilt.android.components.ActivityComponent;
import dagger.hilt.android.testing.HiltAndroidRule;
import dagger.hilt.android.testing.HiltAndroidTest;
import dagger.hilt.android.testing.HiltTestApplication;
import javax.inject.Inject;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.annotation.Config;

@HiltAndroidTest
@RunWith(AndroidJUnit4.class)
// Robolectric requires Java9 to run API 29 and above, so use API 28 instead
@Config(sdk = Build.VERSION_CODES.P, application = HiltTestApplication.class)
public class ActivityInjectedSavedStateViewModelTest {

  private static final String DATA_KEY = "TEST_KEY";

  @Rule public final HiltAndroidRule rule = new HiltAndroidRule(this);

  @Test
  public void memberInjectedViewModelWithSavedState() {
    Intent intent = new Intent(getApplicationContext(), TestActivity.class);
    intent.putExtra(DATA_KEY, "test data");
    try (ActivityScenario<TestActivity> scenario = ActivityScenario.launch(intent)) {
      scenario.onActivity(
          activity -> {
            String data = activity.myViewModel.handle.get(DATA_KEY);
            assertThat(data).isEqualTo("test data");
          });
    }
  }

  // Note that assertion of object not being yet injected is in the SuperActivity, while the
  // assertion in the scenario is confirming injection eventually does occur.
  @Test
  public void notYetMemberInjectedSuperActivity() {
    try (ActivityScenario<TestActivityWithSuperActivity> scenario =
        ActivityScenario.launch(TestActivityWithSuperActivity.class)) {
      scenario.onActivity(activity -> assertThat(activity.someObject).isNotNull());
    }
  }

  @AndroidEntryPoint(FragmentActivity.class)
  public static final class TestActivity
      extends Hilt_ActivityInjectedSavedStateViewModelTest_TestActivity {
    @Inject MyViewModel myViewModel;
  }

  @AndroidEntryPoint(SuperActivity.class)
  public static final class TestActivityWithSuperActivity
      extends Hilt_ActivityInjectedSavedStateViewModelTest_TestActivityWithSuperActivity {}

  public static class SuperActivity extends FragmentActivity {
    @Inject Object someObject;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
      assertThat(someObject).isNull(); // not yet injected
      super.onCreate(savedInstanceState);
    }
  }

  @Module
  @InstallIn(ActivityComponent.class)
  static final class MyViewModelModel {
    @Provides
    static MyViewModel provideModel(FragmentActivity activity) {
      return new ViewModelProvider(activity).get(MyViewModel.class);
    }

    @Provides
    static Object provideObject() {
      return new Object();
    }
  }

  public static final class MyViewModel extends ViewModel {
    final SavedStateHandle handle;

    public MyViewModel(SavedStateHandle handle) {
      this.handle = handle;
    }
  }
}