Propagating the exceptions to the clients. (#856)

* Propagating the exceptions to the clients.

* Adding javadocs for StateListener class.

Author: ankitaj224

firebase-installations/src/androidTest/java/com/google/firebase/installations/FirebaseInstallationsInstrumentedTest.java

@@ -386,7 +386,7 @@ public void testGetAuthToken_PersistedFidError_failure() throws Exception {
           .isInstanceOf(FirebaseInstallationsException.class);
       assertWithMessage("Exception status doesn't match")
           .that(((FirebaseInstallationsException) expected.getCause()).getStatus())
-          .isEqualTo(FirebaseInstallationsException.Status.SDK_INTERNAL_ERROR);
+          .isEqualTo(FirebaseInstallationsException.Status.CLIENT_ERROR);
     }
   }
 

firebase-installations/src/main/java/com/google/firebase/installations/FirebaseInstallations.java

@@ -197,6 +197,19 @@ private void triggerOnStateReached(PersistedFidEntry persistedFidEntry) {
     }
   }
 
+  private void triggerOnException(PersistedFidEntry persistedFidEntry, Exception exception) {
+    synchronized (lock) {
+      Iterator<StateListener> it = listeners.iterator();
+      while (it.hasNext()) {
+        StateListener l = it.next();
+        boolean doneListening = l.onException(persistedFidEntry, exception);
+        if (doneListening) {
+          it.remove();
+        }
+      }
+    }
+  }
+
   private final void doRegistration() {
     try {
       PersistedFidEntry persistedFidEntry = persistedFid.readPersistedFidEntryValue();
@@ -248,7 +261,7 @@ private final void doRegistration() {
               .setRegistrationStatus(RegistrationStatus.REGISTER_ERROR)
               .build();
       persistedFid.insertOrUpdatePersistedFidEntry(errorFidEntry);
-      triggerOnStateReached(errorFidEntry);
+      triggerOnException(errorFidEntry, e);
     }
   }
 

firebase-installations/src/main/java/com/google/firebase/installations/GetAuthTokenListener.java

@@ -42,12 +42,13 @@ public boolean onStateReached(
               .build());
       return true;
     }
+    return false;
+  }
 
+  @Override
+  public boolean onException(PersistedFidEntry persistedFidEntry, Exception exception) {
     if (persistedFidEntry.isErrored()) {
-      resultTaskCompletionSource.setException(
-          new FirebaseInstallationsException(
-              "Firebase Installation is not registered.",
-              FirebaseInstallationsException.Status.SDK_INTERNAL_ERROR));
+      resultTaskCompletionSource.trySetException(exception);
       return true;
     }
     return false;

firebase-installations/src/main/java/com/google/firebase/installations/GetIdListener.java

@@ -27,15 +27,16 @@ public GetIdListener(TaskCompletionSource<String> taskCompletionSource) {
   @Override
   public boolean onStateReached(PersistedFidEntry persistedFidEntry, boolean unused) {
     if (persistedFidEntry.isUnregistered() || persistedFidEntry.isRegistered()) {
-      taskCompletionSource.setResult(persistedFidEntry.getFirebaseInstallationId());
+      taskCompletionSource.trySetResult(persistedFidEntry.getFirebaseInstallationId());
       return true;
     }
+    return false;
+  }
 
+  @Override
+  public boolean onException(PersistedFidEntry persistedFidEntry, Exception exception) {
     if (persistedFidEntry.isErrored()) {
-      taskCompletionSource.setException(
-          new FirebaseInstallationsException(
-              "Failed to update client side cache.",
-              FirebaseInstallationsException.Status.CLIENT_ERROR));
+      taskCompletionSource.trySetException(exception);
       return true;
     }
     return false;

firebase-installations/src/main/java/com/google/firebase/installations/StateListener.java

@@ -17,5 +17,15 @@
 import com.google.firebase.installations.local.PersistedFidEntry;
 
 interface StateListener {
+  /**
+   * Returns {@code true} if the defined {@link PersistedFidEntry} state is reached, {@code false}
+   * otherwise.
+   */
   boolean onStateReached(PersistedFidEntry persistedFidEntry, boolean shouldRefreshAuthToken);
+
+  /**
+   * Returns {@code true} if an exception is thrown while registering a Firebase Installation,
+   * {@code false} otherwise.
+   */
+  boolean onException(PersistedFidEntry persistedFidEntry, Exception exception);
 }