Address review comments.

Author: rosalyntan

appcheck/firebase-appcheck/firebase-appcheck.gradle

@@ -50,6 +50,7 @@ dependencies {
 
     javadocClasspath 'com.google.auto.value:auto-value-annotations:1.6.6'
 
+    testImplementation project(':integ-testing')
     testImplementation 'junit:junit:4.13-beta-2'
     testImplementation 'org.mockito:mockito-core:2.25.0'
     testImplementation 'org.mockito:mockito-inline:2.25.0'

appcheck/firebase-appcheck/src/main/java/com/google/firebase/appcheck/FirebaseAppCheckRegistrar.java

@@ -29,7 +29,7 @@
 import com.google.firebase.platforminfo.LibraryVersionComponent;
 import java.util.Arrays;
 import java.util.List;
-import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 
 /**
@@ -44,24 +44,23 @@ public class FirebaseAppCheckRegistrar implements ComponentRegistrar {
 
   @Override
   public List<Component<?>> getComponents() {
-    Qualified<ExecutorService> backgroundExecutorService =
-        Qualified.qualified(Background.class, ExecutorService.class);
+    Qualified<Executor> backgroundExecutor = Qualified.qualified(Background.class, Executor.class);
     Qualified<ScheduledExecutorService> blockingScheduledExecutorService =
         Qualified.qualified(Blocking.class, ScheduledExecutorService.class);
 
     return Arrays.asList(
         Component.builder(FirebaseAppCheck.class, (InternalAppCheckTokenProvider.class))
             .name(LIBRARY_NAME)
             .add(Dependency.required(FirebaseApp.class))
-            .add(Dependency.required(backgroundExecutorService))
+            .add(Dependency.required(backgroundExecutor))
             .add(Dependency.required(blockingScheduledExecutorService))
             .add(Dependency.optionalProvider(HeartBeatController.class))
             .factory(
                 (container) ->
                     new DefaultFirebaseAppCheck(
                         container.get(FirebaseApp.class),
                         container.getProvider(HeartBeatController.class),
-                        container.get(backgroundExecutorService),
+                        container.get(backgroundExecutor),
                         container.get(blockingScheduledExecutorService)))
             .alwaysEager()
             .build(),

appcheck/firebase-appcheck/src/main/java/com/google/firebase/appcheck/internal/DefaultFirebaseAppCheck.java

@@ -38,7 +38,7 @@
 import com.google.firebase.inject.Provider;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 
 public class DefaultFirebaseAppCheck extends FirebaseAppCheck {
@@ -51,7 +51,7 @@ public class DefaultFirebaseAppCheck extends FirebaseAppCheck {
   private final List<AppCheckListener> appCheckListenerList;
   private final StorageHelper storageHelper;
   private final TokenRefreshManager tokenRefreshManager;
-  private final ExecutorService backgroundExecutor;
+  private final Executor backgroundExecutor;
   private final ScheduledExecutorService scheduledExecutorService;
   private final Task<Void> retrieveStoredTokenTask;
   private final Clock clock;
@@ -63,7 +63,7 @@ public class DefaultFirebaseAppCheck extends FirebaseAppCheck {
   public DefaultFirebaseAppCheck(
       @NonNull FirebaseApp firebaseApp,
       @NonNull Provider<HeartBeatController> heartBeatController,
-      @Background ExecutorService backgroundExecutor,
+      @Background Executor backgroundExecutor,
       @Blocking ScheduledExecutorService scheduledExecutorService) {
     checkNotNull(firebaseApp);
     checkNotNull(heartBeatController);
@@ -81,7 +81,7 @@ public DefaultFirebaseAppCheck(
     this.clock = new Clock.DefaultClock();
   }
 
-  private Task<Void> retrieveStoredAppCheckTokenInBackground(@NonNull ExecutorService executor) {
+  private Task<Void> retrieveStoredAppCheckTokenInBackground(@NonNull Executor executor) {
     TaskCompletionSource<Void> taskCompletionSource = new TaskCompletionSource<>();
     executor.execute(
         () -> {

appcheck/firebase-appcheck/src/test/java/com/google/firebase/appcheck/FirebaseAppCheckRegistrarTest.java

@@ -24,7 +24,7 @@
 import com.google.firebase.components.Qualified;
 import com.google.firebase.heartbeatinfo.HeartBeatController;
 import java.util.List;
-import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -44,7 +44,7 @@ public void testGetComponents() {
     assertThat(firebaseAppCheckComponent.getDependencies())
         .containsExactly(
             Dependency.required(FirebaseApp.class),
-            Dependency.required(Qualified.qualified(Background.class, ExecutorService.class)),
+            Dependency.required(Qualified.qualified(Background.class, Executor.class)),
             Dependency.required(
                 Qualified.qualified(Blocking.class, ScheduledExecutorService.class)),
             Dependency.optionalProvider(HeartBeatController.class));

appcheck/firebase-appcheck/src/test/java/com/google/firebase/appcheck/internal/DefaultFirebaseAppCheckTest.java

@@ -17,24 +17,24 @@
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static org.robolectric.Shadows.shadowOf;
 
+import android.os.Looper;
 import androidx.test.core.app.ApplicationProvider;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
-import com.google.common.util.concurrent.MoreExecutors;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.appcheck.AppCheckProvider;
 import com.google.firebase.appcheck.AppCheckProviderFactory;
 import com.google.firebase.appcheck.AppCheckToken;
 import com.google.firebase.appcheck.AppCheckTokenResult;
 import com.google.firebase.appcheck.FirebaseAppCheck.AppCheckListener;
 import com.google.firebase.appcheck.interop.AppCheckTokenListener;
+import com.google.firebase.concurrent.TestOnlyExecutors;
 import com.google.firebase.heartbeatinfo.HeartBeatController;
-import java.util.concurrent.ScheduledExecutorService;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -44,11 +44,12 @@
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 import org.robolectric.annotation.LooperMode;
+import org.robolectric.annotation.LooperMode.Mode;
 
 /** Tests for {@link DefaultFirebaseAppCheck}. */
 @RunWith(RobolectricTestRunner.class)
 @Config(manifest = Config.NONE)
-@LooperMode(LooperMode.Mode.LEGACY)
+@LooperMode(Mode.PAUSED)
 public class DefaultFirebaseAppCheckTest {
 
   private static final String EXCEPTION_TEXT = "exceptionText";
@@ -82,8 +83,10 @@ public void setup() {
         new DefaultFirebaseAppCheck(
             mockFirebaseApp,
             () -> mockHeartBeatController,
-            MoreExecutors.newDirectExecutorService(),
-            mock(ScheduledExecutorService.class));
+            TestOnlyExecutors.background(),
+            TestOnlyExecutors.blocking());
+
+    shadowOf(Looper.getMainLooper()).idle();
   }
 
   @Test
@@ -94,8 +97,8 @@ public void testConstructor_nullFirebaseApp_expectThrows() {
           new DefaultFirebaseAppCheck(
               null,
               () -> mockHeartBeatController,
-              MoreExecutors.newDirectExecutorService(),
-              mock(ScheduledExecutorService.class));
+              TestOnlyExecutors.background(),
+              TestOnlyExecutors.blocking());
         });
   }
 
@@ -105,10 +108,7 @@ public void testConstructor_nullHeartBeatControllerProvider_expectThrows() {
         NullPointerException.class,
         () -> {
           new DefaultFirebaseAppCheck(
-              mockFirebaseApp,
-              null,
-              MoreExecutors.newDirectExecutorService(),
-              mock(ScheduledExecutorService.class));
+              mockFirebaseApp, null, TestOnlyExecutors.background(), TestOnlyExecutors.blocking());
         });
   }
 
@@ -343,6 +343,7 @@ public void testGetToken_existingValidToken_forceRefresh_requestsNewToken() {
     defaultFirebaseAppCheck.installAppCheckProviderFactory(mockAppCheckProviderFactory);
 
     defaultFirebaseAppCheck.getToken(/* forceRefresh= */ true);
+    shadowOf(Looper.getMainLooper()).idle();
 
     verify(mockAppCheckProvider).getToken();
   }