feat(auth): Add API to look up users by federated ID.

src/main/java/com/google/firebase/auth/AbstractFirebaseAuth.java

@@ -553,6 +553,64 @@ protected UserRecord execute() throws FirebaseAuthException {
     };
   }
 
+  /**
+   * Gets the user data for the user corresponding to a given provider id.
+   *
+   * @param providerId Identifier for the given federated provider, for example,
+   *     "google.com" for the Google provider.
+   * @param uid The user identifier with the given provider.
+   * @return A {@link UserRecord} instance.
+   * @throws IllegalArgumentException If the uid is null or empty, or if
+   *     the providerId is null, empty, or does not belong to a federated provider.
+   * @throws FirebaseAuthException If an error occurs while retrieving user data.
+   */
+  public UserRecord getUserByProviderUid(
+      @NonNull String providerId, @NonNull String uid) throws FirebaseAuthException {
+    return getUserByProviderUidOp(providerId, uid).call();
+  }
+
+  /**
+   * Gets the user data for the user corresponding to a given provider id.
+   *
+   * @param providerId Identifer for the given federated provider, for example,
+   *     "google.com" for the Google provider.
+   * @param uid The user identifier with the given provider.
+   * @return An {@code ApiFuture} which will complete successfully with a {@link UserRecord}
+   *     instance. If an error occurs while retrieving user data or if the provider ID and uid
+   *     do not correspond to a user, the future throws a {@link FirebaseAuthException}.
+   * @throws IllegalArgumentException If the uid is null or empty, or if
+   *     the provider ID is null, empty, or does not belong to a federated provider.
+   */
+  public ApiFuture<UserRecord> getUserByProviderUidAsync(
+      @NonNull String providerId, @NonNull String uid) {
+    return getUserByProviderUidOp(providerId, uid).callAsync(firebaseApp);
+  }
+
+  private CallableOperation<UserRecord, FirebaseAuthException> getUserByProviderUidOp(
+      final String providerId, final String uid) {
+    checkArgument(!Strings.isNullOrEmpty(providerId), "providerId must not be null or empty");
+    checkArgument(!Strings.isNullOrEmpty(uid), "uid must not be null or empty");
+
+    // Although we don't really advertise it, we want to also handle
+    // non-federated idps with this call. So if we detect one of them, we'll
+    // reroute this request appropriately.
+    if (providerId == "phone") {
+      return this.getUserByPhoneNumberOp(uid);
+    } else if (providerId == "email") {
+      return this.getUserByEmailOp(uid);
+    }
+
+    checkArgument(!providerId.equals("password")
+        && !providerId.equals("anonymous"), "providerId must belong to a federated provider");
+    final FirebaseUserManager userManager = getUserManager();
+    return new CallableOperation<UserRecord, FirebaseAuthException>() {
+      @Override
+      protected UserRecord execute() throws FirebaseAuthException {
+        return userManager.getUserByProviderUid(providerId, uid);
+      }
+    };
+  }
+
   /**
    * Gets a page of users starting from the specified {@code pageToken}. Page size is limited to
    * 1000 users.

src/main/java/com/google/firebase/auth/FirebaseUserManager.java

@@ -145,6 +145,15 @@ Set<UserRecord> getAccountInfo(@NonNull Collection<UserIdentifier> identifiers)
     return results;
   }
 
+  UserRecord getUserByProviderUid(
+      String providerId, String uid) throws FirebaseAuthException {
+    final Map<String, Object> payload = ImmutableMap.<String, Object>of(
+        "federatedUserId", ImmutableList.of(
+            ImmutableMap.<String, Object>builder()
+            .put("rawId", uid).put("providerId", providerId).build()));
+    return lookupUserAccount(payload, uid);
+  }
+
   String createUser(UserRecord.CreateRequest request) throws FirebaseAuthException {
     GenericJson response = post("/accounts", request.getProperties(), GenericJson.class);
     return (String) response.get("localId");

src/test/java/com/google/firebase/auth/FirebaseAuthIT.java

@@ -265,6 +265,35 @@ public void testCreateUserWithParams() throws Exception {
     checkRecreateUser(randomUser.getUid());
   }
 
+  @Test
+  public void testLookupUserByPhone() throws Exception {
+    UserRecord user1 = createTemporaryUser();
+    UserRecord user2 = importTemporaryUser();
+
+    UserRecord lookedUpRecord = auth.getUserByPhoneNumberAsync(
+        user1.getPhoneNumber()).get();
+    assertEquals(user1.getUid(), lookedUpRecord.getUid());
+
+    lookedUpRecord = auth.getUserByPhoneNumberAsync(user2.getPhoneNumber()).get();
+    assertEquals(user2.getUid(), lookedUpRecord.getUid());
+  }
+
+  @Test
+  public void testLookupUserByProviderUid() throws Exception {
+    UserRecord user = importTemporaryUser();
+
+    UserRecord lookedUpRecord = auth.getUserByProviderUidAsync(
+        "google.com", user.getUid() + "_google.com").get();
+    assertEquals(user.getUid(), lookedUpRecord.getUid());
+    assertEquals(2, lookedUpRecord.getProviderData().length);
+    List<String> providers = new ArrayList<>();
+    for (UserInfo provider : lookedUpRecord.getProviderData()) {
+      providers.add(provider.getProviderId());
+    }
+    assertTrue(providers.contains("phone"));
+    assertTrue(providers.contains("google.com"));
+  }
+
   @Test
   public void testUserLifecycle() throws Exception {
     // Create user
@@ -929,6 +958,54 @@ public void onSuccess(ListProviderConfigsPage<SamlProviderConfig> result) {
     assertNull(error.get());
   }
 
+  /**
+   * Create a temporary user. This user will automatically be cleaned up after testing completes.
+   */
+  private UserRecord createTemporaryUser() throws Exception {
+    RandomUser randomUser = UserTestUtils.generateRandomUserInfo();
+
+    UserRecord.CreateRequest user = new UserRecord.CreateRequest()
+        .setUid(randomUser.getUid())
+        .setDisplayName("Random User")
+        .setEmail(randomUser.getEmail())
+        .setEmailVerified(true)
+        .setPhoneNumber(randomUser.getPhoneNumber())
+        .setPhotoUrl("https://example.com/photo.png")
+        .setPassword("password");
+
+    return temporaryUser.create(user);
+  }
+
+  /**
+   * Import a temporary user. This user will automatically be cleaned up after testing completes.
+   */
+  private UserRecord importTemporaryUser() throws Exception {
+    RandomUser randomUser = UserTestUtils.generateRandomUserInfo();
+
+    ImportUserRecord.Builder builder = ImportUserRecord.builder()
+        .setUid(randomUser.getUid())
+        .setDisabled(false)
+        .setEmail(randomUser.getEmail())
+        .setEmailVerified(true)
+        .setPhoneNumber(randomUser.getPhoneNumber())
+        .setUserMetadata(
+            new UserMetadata(/* creationTimestamp= */ 20L, /* lastSignInTimestamp= */ 20L,
+                /* lastRefreshTimestamp= */ 20L))
+        .addUserProvider(
+            UserProvider.builder()
+            .setProviderId("google.com")
+            .setUid(randomUser.getUid() + "_google.com")
+            .build());
+
+    ImportUserRecord user = builder.build();
+    UserImportResult result = auth.importUsersAsync(ImmutableList.of(user)).get();
+    assertEquals(result.getSuccessCount(), 1);
+    assertEquals(result.getFailureCount(), 0);
+    temporaryUser.registerUid(randomUser.getUid());
+
+    return auth.getUserAsync(randomUser.getUid()).get();
+  }
+
   private Map<String, String> parseLinkParameters(String link) throws Exception {
     Map<String, String> result = new HashMap<>();
     int queryBegin = link.indexOf('?');

src/test/java/com/google/firebase/auth/FirebaseUserManagerTest.java

@@ -349,6 +349,56 @@ public void testInvalidProviderIdentifier() {
     }
   }
 
+  @Test
+  public void testGetUserByProviderUidWithInvalidProviderId() throws Exception {
+    initializeAppForUserManagement();
+    try {
+      FirebaseAuth.getInstance().getUserByProviderUidAsync("", "uid").get();
+      fail("No error thrown for invalid request");
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
+  @Test
+  public void testGetUserByProviderUidWithInvalidProviderUid() throws Exception {
+    initializeAppForUserManagement();
+    try {
+      FirebaseAuth.getInstance().getUserByProviderUidAsync("id", "").get();
+      fail("No error thrown for invalid request");
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
+  @Test
+  public void testGetUserByProviderUidWithValidInput() throws Exception {
+    TestResponseInterceptor interceptor = initializeAppForUserManagement(
+        TestUtils.loadResource("getUser.json"));
+    UserRecord userRecord = FirebaseAuth.getInstance()
+        .getUserByProviderUidAsync("google.com", "google_uid").get();
+    checkUserRecord(userRecord);
+    checkRequestHeaders(interceptor);
+  }
+
+  @Test
+  public void testGetUserByProviderUidWithPhone() throws Exception {
+    TestResponseInterceptor interceptor = initializeAppForUserManagement(
+        TestUtils.loadResource("getUser.json"));
+    UserRecord userRecord = FirebaseAuth.getInstance()
+        .getUserByProviderUidAsync("phone", "+1234567890").get();
+    checkUserRecord(userRecord);
+    checkRequestHeaders(interceptor);
+  }
+
+  @Test
+  public void testGetUserByProviderUidWithEmail() throws Exception {
+    TestResponseInterceptor interceptor = initializeAppForUserManagement(
+        TestUtils.loadResource("getUser.json"));
+    UserRecord userRecord = FirebaseAuth.getInstance()
+        .getUserByProviderUidAsync("email", "[email protected]").get();
+    checkUserRecord(userRecord);
+    checkRequestHeaders(interceptor);
+  }
+
   @Test
   public void testListUsers() throws Exception {
     final TestResponseInterceptor interceptor = initializeAppForUserManagement(
@@ -2761,7 +2811,7 @@ private static void checkUserRecord(UserRecord userRecord) {
     assertEquals("http://www.example.com/testuser/photo.png", userRecord.getPhotoUrl());
     assertEquals(1234567890, userRecord.getUserMetadata().getCreationTimestamp());
     assertEquals(0, userRecord.getUserMetadata().getLastSignInTimestamp());
-    assertEquals(2, userRecord.getProviderData().length);
+    assertEquals(3, userRecord.getProviderData().length);
     assertFalse(userRecord.isDisabled());
     assertTrue(userRecord.isEmailVerified());
     assertEquals(1494364393000L, userRecord.getTokensValidAfterTimestamp());
@@ -2781,6 +2831,10 @@ private static void checkUserRecord(UserRecord userRecord) {
     assertEquals("+1234567890", provider.getPhoneNumber());
     assertEquals("phone", provider.getProviderId());
 
+    provider = userRecord.getProviderData()[2];
+    assertEquals("google_uid", provider.getUid());
+    assertEquals("google.com", provider.getProviderId());
+
     Map<String, Object> claims = userRecord.getCustomClaims();
     assertEquals(2, claims.size());
     assertTrue((boolean) claims.get("admin"));

src/test/java/com/google/firebase/snippets/FirebaseAuthSnippets.java

@@ -94,6 +94,16 @@ public static void getUserByPhoneNumber(
     // [END get_user_by_phone]
   }
 
+  public static void getUserByProviderUId(
+      String providerId, String uid) throws FirebaseAuthException {
+    // [START get_user_by_provider_uid]
+    UserRecord userRecord = FirebaseAuth.getInstance().getUserByProviderUid(
+        providerId, uid);
+    // See the UserRecord reference doc for the contents of userRecord.
+    System.out.println("Successfully fetched user data: " + userRecord.getUid());
+    // [END get_user_by_provider_uid]
+  }
+
   public static void createUser() throws FirebaseAuthException {
     // [START create_user]
     CreateRequest request = new CreateRequest()

src/test/resources/getUser.json

@@ -17,6 +17,9 @@
       "providerId" : "phone",
       "phoneNumber" : "+1234567890",
       "rawId" : "+1234567890"
+    }, {
+      "providerId" : "google.com",
+      "rawId" : "google_uid"
     } ],
     "photoUrl" : "http://www.example.com/testuser/photo.png",
     "passwordHash" : "passwordhash",

src/test/resources/listUsers.json

@@ -16,6 +16,9 @@
       "providerId" : "phone",
       "phoneNumber" : "+1234567890",
       "rawId" : "+1234567890"
+    }, {
+      "providerId" : "google.com",
+      "rawId" : "google_uid"
     } ],
     "photoUrl" : "http://www.example.com/testuser/photo.png",
     "passwordHash" : "passwordHash",
@@ -43,6 +46,9 @@
       "providerId" : "phone",
       "phoneNumber" : "+1234567890",
       "rawId" : "+1234567890"
+    }, {
+      "providerId" : "google.com",
+      "rawId" : "google_uid"
     } ],
     "photoUrl" : "http://www.example.com/testuser/photo.png",
     "passwordHash" : "passwordHash",