Add dynamic module support to Firestore (#2432)

Author: dconeybe

firebase-firestore/firebase-firestore.gradle

@@ -129,7 +129,7 @@ dependencies {
     implementation 'com.google.android.gms:play-services-base:17.0.0'
 
     implementation 'com.squareup.okhttp:okhttp:2.7.5'
-    implementation('com.google.firebase:firebase-auth-interop:18.0.0') {
+    implementation('com.google.firebase:firebase-auth-interop:19.0.2') {
         exclude group: "com.google.firebase", module: "firebase-common"
     }
 

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/remote/StreamTest.java

@@ -29,10 +29,10 @@
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.gms.tasks.Task;
-import com.google.firebase.firestore.auth.EmptyCredentialsProvider;
 import com.google.firebase.firestore.model.SnapshotVersion;
 import com.google.firebase.firestore.model.mutation.Mutation;
 import com.google.firebase.firestore.model.mutation.MutationResult;
+import com.google.firebase.firestore.testutil.EmptyCredentialsProvider;
 import com.google.firebase.firestore.testutil.IntegrationTestUtil;
 import com.google.firebase.firestore.util.AsyncQueue;
 import com.google.firebase.firestore.util.AsyncQueue.TimerId;

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/testutil/IntegrationTestUtil.java

@@ -36,7 +36,6 @@
 import com.google.firebase.firestore.ListenerRegistration;
 import com.google.firebase.firestore.MetadataChanges;
 import com.google.firebase.firestore.QuerySnapshot;
-import com.google.firebase.firestore.auth.EmptyCredentialsProvider;
 import com.google.firebase.firestore.auth.User;
 import com.google.firebase.firestore.core.DatabaseInfo;
 import com.google.firebase.firestore.local.Persistence;

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestore.java

@@ -31,7 +31,6 @@
 import com.google.firebase.emulators.EmulatedServiceSettings;
 import com.google.firebase.firestore.FirebaseFirestoreException.Code;
 import com.google.firebase.firestore.auth.CredentialsProvider;
-import com.google.firebase.firestore.auth.EmptyCredentialsProvider;
 import com.google.firebase.firestore.auth.FirebaseAuthCredentialsProvider;
 import com.google.firebase.firestore.core.ActivityScope;
 import com.google.firebase.firestore.core.AsyncEventListener;
@@ -48,6 +47,7 @@
 import com.google.firebase.firestore.util.Function;
 import com.google.firebase.firestore.util.Logger;
 import com.google.firebase.firestore.util.Logger.Level;
+import com.google.firebase.inject.Deferred;
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
@@ -117,7 +117,7 @@ private static FirebaseFirestore getInstance(@NonNull FirebaseApp app, @NonNull
   static FirebaseFirestore newInstance(
       @NonNull Context context,
       @NonNull FirebaseApp app,
-      @Nullable InternalAuthProvider authProvider,
+      @NonNull Deferred<InternalAuthProvider> authProvider,
       @NonNull String database,
       @NonNull InstanceRegistry instanceRegistry,
       @Nullable GrpcMetadataProvider metadataProvider) {
@@ -129,13 +129,7 @@ static FirebaseFirestore newInstance(
 
     AsyncQueue queue = new AsyncQueue();
 
-    CredentialsProvider provider;
-    if (authProvider == null) {
-      Logger.debug(TAG, "Firebase Auth not available, falling back to unauthenticated usage.");
-      provider = new EmptyCredentialsProvider();
-    } else {
-      provider = new FirebaseAuthCredentialsProvider(authProvider);
-    }
+    CredentialsProvider provider = new FirebaseAuthCredentialsProvider(authProvider);
 
     // Firestore uses a different database for each app name. Note that we don't use
     // app.getPersistenceKey() here because it includes the application ID which is related

firebase-firestore/src/main/java/com/google/firebase/firestore/FirestoreMultiDbComponent.java

@@ -24,6 +24,7 @@
 import com.google.firebase.FirebaseOptions;
 import com.google.firebase.auth.internal.InternalAuthProvider;
 import com.google.firebase.firestore.remote.GrpcMetadataProvider;
+import com.google.firebase.inject.Deferred;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
@@ -40,13 +41,13 @@ class FirestoreMultiDbComponent
 
   private final FirebaseApp app;
   private final Context context;
-  private final InternalAuthProvider authProvider;
+  private final Deferred<InternalAuthProvider> authProvider;
   private final GrpcMetadataProvider metadataProvider;
 
   FirestoreMultiDbComponent(
       @NonNull Context context,
       @NonNull FirebaseApp app,
-      @Nullable InternalAuthProvider authProvider,
+      @NonNull Deferred<InternalAuthProvider> authProvider,
       @Nullable GrpcMetadataProvider metadataProvider) {
     this.context = context;
     this.app = app;

firebase-firestore/src/main/java/com/google/firebase/firestore/FirestoreRegistrar.java

@@ -47,14 +47,14 @@ public List<Component<?>> getComponents() {
             .add(Dependency.required(Context.class))
             .add(Dependency.optionalProvider(HeartBeatInfo.class))
             .add(Dependency.optionalProvider(UserAgentPublisher.class))
-            .add(Dependency.optional(InternalAuthProvider.class))
+            .add(Dependency.deferred(InternalAuthProvider.class))
             .add(Dependency.optional(FirebaseOptions.class))
             .factory(
                 c ->
                     new FirestoreMultiDbComponent(
                         c.get(Context.class),
                         c.get(FirebaseApp.class),
-                        c.get(InternalAuthProvider.class),
+                        c.getDeferred(InternalAuthProvider.class),
                         new FirebaseClientGrpcMetadataProvider(
                             c.getProvider(UserAgentPublisher.class),
                             c.getProvider(HeartBeatInfo.class),

firebase-firestore/src/main/java/com/google/firebase/firestore/auth/FirebaseAuthCredentialsProvider.java

@@ -14,17 +14,22 @@
 
 package com.google.firebase.firestore.auth;
 
+import android.annotation.SuppressLint;
+import androidx.annotation.GuardedBy;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
+import com.google.firebase.FirebaseApiNotAvailableException;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.auth.GetTokenResult;
 import com.google.firebase.auth.internal.IdTokenListener;
 import com.google.firebase.auth.internal.InternalAuthProvider;
 import com.google.firebase.firestore.util.Executors;
 import com.google.firebase.firestore.util.Listener;
 import com.google.firebase.firestore.util.Logger;
+import com.google.firebase.inject.Deferred;
+import com.google.firebase.inject.Provider;
 
 /**
  * FirebaseAuthCredentialsProvider uses Firebase Auth via {@link FirebaseApp} to get an auth token.
@@ -40,50 +45,54 @@ public final class FirebaseAuthCredentialsProvider extends CredentialsProvider {
 
   private static final String LOG_TAG = "FirebaseAuthCredentialsProvider";
 
-  private final InternalAuthProvider authProvider;
-
   /**
    * The listener registered with FirebaseApp; used to stop receiving auth changes once
    * changeListener is removed.
    */
-  private final IdTokenListener idTokenListener;
+  private final IdTokenListener idTokenListener = result -> onIdTokenChanged();
 
-  /** The listener to be notified of credential changes (sign-in / sign-out, token changes). */
-  @Nullable private Listener<User> changeListener;
+  /**
+   * The {@link Provider} that gives access to the {@link InternalAuthProvider} instance; initially,
+   * its {@link Provider#get} method returns {@code null}, but will be changed to a new {@link
+   * Provider} once the "auth" module becomes available.
+   */
+  @Nullable
+  @GuardedBy("this")
+  private InternalAuthProvider internalAuthProvider;
 
-  /** The current user as reported to us via our IdTokenListener. */
-  private User currentUser;
+  /** The listener to be notified of credential changes (sign-in / sign-out, token changes). */
+  @Nullable
+  @GuardedBy("this")
+  private Listener<User> changeListener;
 
   /** Counter used to detect if the token changed while a getToken request was outstanding. */
+  @GuardedBy("this")
   private int tokenCounter;
 
+  @GuardedBy("this")
   private boolean forceRefresh;
 
   /** Creates a new FirebaseAuthCredentialsProvider. */
-  public FirebaseAuthCredentialsProvider(InternalAuthProvider authProvider) {
-    this.authProvider = authProvider;
-    this.idTokenListener =
-        token -> {
+  @SuppressLint("ProviderAssignment") // TODO: Remove this @SuppressLint once b/181014061 is fixed.
+  public FirebaseAuthCredentialsProvider(Deferred<InternalAuthProvider> deferredAuthProvider) {
+    deferredAuthProvider.whenAvailable(
+        provider -> {
           synchronized (this) {
-            currentUser = getUser();
-            tokenCounter++;
-
-            if (changeListener != null) {
-              changeListener.onValue(currentUser);
-            }
+            internalAuthProvider = provider.get();
+            onIdTokenChanged();
+            internalAuthProvider.addIdTokenListener(idTokenListener);
           }
-        };
-    currentUser = getUser();
-    tokenCounter = 0;
-
-    authProvider.addIdTokenListener(idTokenListener);
+        });
   }
 
   @Override
   public synchronized Task<String> getToken() {
-    boolean doForceRefresh = forceRefresh;
+    if (internalAuthProvider == null) {
+      return Tasks.forException(new FirebaseApiNotAvailableException("auth is not available"));
+    }
+
+    Task<GetTokenResult> res = internalAuthProvider.getAccessToken(forceRefresh);
     forceRefresh = false;
-    Task<GetTokenResult> res = authProvider.getAccessToken(doForceRefresh);
 
     // Take note of the current value of the tokenCounter so that this method can fail (with a
     // FirebaseFirestoreException) if there is a token change while the request is outstanding.
@@ -118,18 +127,29 @@ public synchronized void setChangeListener(@NonNull Listener<User> changeListene
     this.changeListener = changeListener;
 
     // Fire the initial event.
-    changeListener.onValue(currentUser);
+    changeListener.onValue(getUser());
   }
 
   @Override
   public synchronized void removeChangeListener() {
     changeListener = null;
-    authProvider.removeIdTokenListener(idTokenListener);
+
+    if (internalAuthProvider != null) {
+      internalAuthProvider.removeIdTokenListener(idTokenListener);
+    }
+  }
+
+  /** Invoked when the auth token changes. */
+  private synchronized void onIdTokenChanged() {
+    tokenCounter++;
+    if (changeListener != null) {
+      changeListener.onValue(getUser());
+    }
   }
 
-  /** Returns the current {@link User} as obtained from the given FirebaseApp instance. */
-  private User getUser() {
-    @Nullable String uid = authProvider.getUid();
+  /** Returns the current {@link User} as obtained from the given InternalAuthProvider. */
+  private synchronized User getUser() {
+    @Nullable String uid = (internalAuthProvider == null) ? null : internalAuthProvider.getUid();
     return uid != null ? new User(uid) : User.UNAUTHENTICATED;
   }
 }

firebase-firestore/src/test/java/com/google/firebase/firestore/FirestoreMultiDbComponentTest.java

@@ -24,6 +24,8 @@
 import com.google.firebase.FirebaseOptions;
 import com.google.firebase.auth.internal.InternalAuthProvider;
 import com.google.firebase.firestore.remote.GrpcMetadataProvider;
+import com.google.firebase.firestore.testutil.ImmediateDeferred;
+import com.google.firebase.inject.Deferred;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricTestRunner;
@@ -58,7 +60,9 @@ private static FirebaseApp createApp(String appName) {
   private static FirestoreMultiDbComponent createComponent(FirebaseApp firebaseApp) {
     Context context = InstrumentationRegistry.getInstrumentation().getContext();
     InternalAuthProvider authProvider = mock(InternalAuthProvider.class);
+    Deferred<InternalAuthProvider> deferredAuthProvider = new ImmediateDeferred<>(authProvider);
     GrpcMetadataProvider metadataProvider = mock(GrpcMetadataProvider.class);
-    return new FirestoreMultiDbComponent(context, firebaseApp, authProvider, metadataProvider);
+    return new FirestoreMultiDbComponent(
+        context, firebaseApp, deferredAuthProvider, metadataProvider);
   }
 }