One more continuation in firebase-appcheck.

Author: rosalyntan

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

@@ -78,6 +78,7 @@ public DefaultFirebaseAppCheck(
         new TokenRefreshManager(
             firebaseApp.getApplicationContext(),
             /* firebaseAppCheck= */ this,
+            liteExecutor,
             scheduledExecutorService);
     this.backgroundExecutor = backgroundExecutor;
     this.liteExecutor = liteExecutor;

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

@@ -18,10 +18,11 @@
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 
-import android.annotation.SuppressLint;
 import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
 import com.google.firebase.annotations.concurrent.Blocking;
+import com.google.firebase.annotations.concurrent.Lightweight;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 
@@ -36,15 +37,18 @@ public class DefaultTokenRefresher {
   @VisibleForTesting static final long MAX_DELAY_SECONDS = 16 * 60; // 16 minutes
 
   private final DefaultFirebaseAppCheck firebaseAppCheck;
+  private final Executor liteExecutor;
   private final ScheduledExecutorService scheduledExecutorService;
 
   private volatile ScheduledFuture<?> refreshFuture;
   private volatile long delayAfterFailureSeconds;
 
   DefaultTokenRefresher(
       @NonNull DefaultFirebaseAppCheck firebaseAppCheck,
+      @Lightweight Executor liteExecutor,
       @Blocking ScheduledExecutorService scheduledExecutorService) {
     this.firebaseAppCheck = checkNotNull(firebaseAppCheck);
+    this.liteExecutor = liteExecutor;
     this.scheduledExecutorService = scheduledExecutorService;
     this.delayAfterFailureSeconds = UNSET_DELAY;
   }
@@ -86,12 +90,10 @@ private long getNextRefreshMillis() {
     }
   }
 
-  // TODO(b/261013814): Use an explicit executor in continuations.
-  @SuppressLint("TaskMainThread")
   private void onRefresh() {
     firebaseAppCheck
         .fetchTokenFromProvider()
-        .addOnFailureListener(e -> scheduleRefreshAfterFailure());
+        .addOnFailureListener(liteExecutor, e -> scheduleRefreshAfterFailure());
   }
 
   /** Cancels the in-flight scheduled refresh. */

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

@@ -23,8 +23,10 @@
 import com.google.android.gms.common.api.internal.BackgroundDetector;
 import com.google.android.gms.common.api.internal.BackgroundDetector.BackgroundStateChangeListener;
 import com.google.firebase.annotations.concurrent.Blocking;
+import com.google.firebase.annotations.concurrent.Lightweight;
 import com.google.firebase.appcheck.AppCheckToken;
 import com.google.firebase.appcheck.internal.util.Clock;
+import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 
 /** Class to manage whether or not to schedule an {@link AppCheckToken} refresh attempt. */
@@ -46,10 +48,12 @@ public final class TokenRefreshManager {
   TokenRefreshManager(
       @NonNull Context context,
       @NonNull DefaultFirebaseAppCheck firebaseAppCheck,
+      @Lightweight Executor liteExecutor,
       @Blocking ScheduledExecutorService scheduledExecutorService) {
     this(
         checkNotNull(context),
-        new DefaultTokenRefresher(checkNotNull(firebaseAppCheck), scheduledExecutorService),
+        new DefaultTokenRefresher(
+            checkNotNull(firebaseAppCheck), liteExecutor, scheduledExecutorService),
         new Clock.DefaultClock());
   }
 

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

@@ -24,6 +24,7 @@
 import static org.mockito.Mockito.when;
 
 import com.google.android.gms.tasks.Tasks;
+import com.google.common.util.concurrent.MoreExecutors;
 import com.google.firebase.appcheck.AppCheckToken;
 import java.util.concurrent.ScheduledExecutorService;
 import org.junit.Before;
@@ -44,7 +45,6 @@ public class DefaultTokenRefresherTest {
   private static final long TWO_MINUTES_SECONDS = 2L * 60L;
   private static final long FOUR_MINUTES_SECONDS = 4L * 60L;
   private static final long EIGHT_MINUTES_SECONDS = 8L * 60L;
-  private static final String ERROR = "error";
 
   @Mock DefaultFirebaseAppCheck mockFirebaseAppCheck;
   @Mock ScheduledExecutorService mockScheduledExecutorService;
@@ -59,8 +59,10 @@ public void setUp() {
     when(mockFirebaseAppCheck.fetchTokenFromProvider())
         .thenReturn(Tasks.forResult(mockAppCheckToken));
 
+    // TODO(b/258273630): Use TestOnlyExecutors.
     defaultTokenRefresher =
-        new DefaultTokenRefresher(mockFirebaseAppCheck, mockScheduledExecutorService);
+        new DefaultTokenRefresher(
+            mockFirebaseAppCheck, MoreExecutors.directExecutor(), mockScheduledExecutorService);
   }
 
   @Test