Add operation phone auth (#309)

* Adds operation to verify PhoneNumber requests

* Improvements and unit tests

* Fixes typo

* Addresses comments

- Removes the FIRAuthOperation class.
- Defines the FIRAuthOperationType as an enum in a class of the same name.
- Passes the FIRAuthOperationType value down to the verifyPhoneNumber RPC where it is translated to a string.

* Fixes unit tests

* Actually fixes the unit tests.

10 files changed, 215 insertions, 17 deletions

diff --git a/Example/Auth/Tests/FIRAuthTests.m b/Example/Auth/Tests/FIRAuthTests.m
index 8513063..8e00284 100644
--- a/Example/Auth/Tests/FIRAuthTests.m
+++ b/Example/Auth/Tests/FIRAuthTests.m
@@ -23,6 +23,7 @@
 #import "FirebaseCommunity/FIRGoogleAuthProvider.h"
 #import "FirebaseCommunity/FIRAdditionalUserInfo.h"
 #import "FIRAuth_Internal.h"
+#import "FIRAuthOperationType.h"
 #import "FIRAuthErrorUtils.h"
 #import "FIRAuthDispatcher.h"
 #import "FIRAuthGlobalWorkQueue.h"
@@ -423,6 +424,7 @@ static const NSTimeInterval kWaitInterval = .5;
                        FIRVerifyPhoneNumberResponseCallback callback) {
     XCTAssertEqualObjects(request.verificationCode, kVerificationCode);
     XCTAssertEqualObjects(request.verificationID, kVerificationID);
+    XCTAssertEqual(request.operation, FIRAuthOperationTypeSignUpOrSignIn);
     dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
       id mockVerifyPhoneResponse = OCMClassMock([FIRVerifyPhoneNumberResponse class]);
       [self stubTokensWithMockResponse:mockVerifyPhoneResponse];
diff --git a/Example/Auth/Tests/FIRUserTests.m b/Example/Auth/Tests/FIRUserTests.m
index 62d2eda..3384885 100644
--- a/Example/Auth/Tests/FIRUserTests.m
+++ b/Example/Auth/Tests/FIRUserTests.m
@@ -23,10 +23,11 @@
 #import "FirebaseCommunity/FIRFacebookAuthProvider.h"
 #import "FirebaseCommunity/FIRGoogleAuthProvider.h"
 #import "FirebaseCommunity/FIRAdditionalUserInfo.h"
-#import "FirebaseCommunity/FIRAuth.h"
+#import "FIRAuth_Internal.h"
 #import "FIRAuthErrorUtils.h"
 #import "FIRAuthBackend.h"
 #import "FIRAuthGlobalWorkQueue.h"
+#import "FIRAuthOperationType.h"
 #import "FIRGetAccountInfoRequest.h"
 #import "FIRGetAccountInfoResponse.h"
 #import "FIRSetAccountInfoRequest.h"
@@ -535,7 +536,7 @@ static const NSTimeInterval kExpectationTimeout = 1;
   id userInfoResponse = mockUserInfoWithPhoneNumber(nil);
   [self signInWithEmailPasswordWithMockUserInfoResponse:userInfoResponse
                                              completion:^(FIRUser *user) {
-    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber error:nil];
+    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber isLinkOperation:NO error:nil];
     id userInfoResponseUpdate = mockUserInfoWithPhoneNumber(kPhoneNumber);
     [self expectGetAccountInfoWithMockUserInfoResponse:userInfoResponseUpdate];
 
@@ -1496,7 +1497,7 @@ static const NSTimeInterval kExpectationTimeout = 1;
   id userInfoResponse = mockUserInfoWithPhoneNumber(nil);
   [self signInWithEmailPasswordWithMockUserInfoResponse:userInfoResponse
                                              completion:^(FIRUser *user) {
-    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber error:nil];
+    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber isLinkOperation:YES error:nil];
     id userInfoResponseUpdate = mockUserInfoWithPhoneNumber(kPhoneNumber);
     [self expectGetAccountInfoWithMockUserInfoResponse:userInfoResponseUpdate];
 
@@ -1560,7 +1561,7 @@ static const NSTimeInterval kExpectationTimeout = 1;
   id userInfoResponse = mockUserInfoWithPhoneNumber(nil);
   [self signInWithEmailPasswordWithMockUserInfoResponse:userInfoResponse
                                              completion:^(FIRUser *user) {
-    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber error:nil];
+    [self expectVerifyPhoneNumberRequestWithPhoneNumber:kPhoneNumber isLinkOperation:YES error:nil];
     id userInfoResponseUpdate = mockUserInfoWithPhoneNumber(kPhoneNumber);
     [self expectGetAccountInfoWithMockUserInfoResponse:userInfoResponseUpdate];
 
@@ -1610,7 +1611,7 @@ static const NSTimeInterval kExpectationTimeout = 1;
   [self signInWithEmailPasswordWithMockUserInfoResponse:userInfoResponse
                                              completion:^(FIRUser *user) {
     NSError *error = [FIRAuthErrorUtils providerAlreadyLinkedError];
-    [self expectVerifyPhoneNumberRequestWithPhoneNumber:nil error:error];
+    [self expectVerifyPhoneNumberRequestWithPhoneNumber:nil isLinkOperation:YES error:error];
     FIRPhoneAuthCredential *credential =
         [[FIRPhoneAuthProvider provider] credentialWithVerificationID:kVerificationID
                                                      verificationCode:kVerificationCode];
@@ -1869,15 +1870,23 @@ static const NSTimeInterval kExpectationTimeout = 1;
     @brief Expects a verify phone numner request on the mock backend and calls back with fake
         account data or an error.
     @param phoneNumber Optionally; The phone number to use in the mocked response.
+    @param isLinkOperation Boolean value that indicates whether or not this method is triggered by
+        a link operation.
     @param error Optionally; The error to return in the mocked response.
  */
 - (void)expectVerifyPhoneNumberRequestWithPhoneNumber:(nullable NSString *)phoneNumber
-                                                error:(nullable NSError*)error {
+                                       isLinkOperation:(BOOL)isLinkOperation
+                                                 error:(nullable NSError*)error {
   OCMExpect([_mockBackend verifyPhoneNumber:[OCMArg any] callback:[OCMArg any]])
       .andCallBlock2(^(FIRVerifyPhoneNumberRequest *_Nullable request,
                      FIRVerifyPhoneNumberResponseCallback callback) {
     XCTAssertEqualObjects(request.verificationID, kVerificationID);
     XCTAssertEqualObjects(request.verificationCode, kVerificationCode);
+    if (isLinkOperation) {
+      XCTAssertEqual(request.operation, FIRAuthOperationTypeLink);
+    } else {
+      XCTAssertEqual(request.operation, FIRAuthOperationTypeUpdate);
+    }
     XCTAssertEqualObjects(request.accessToken, kAccessToken);
     dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
       if (error) {
diff --git a/Example/Auth/Tests/FIRVerifyPhoneNumberRequestTests.m b/Example/Auth/Tests/FIRVerifyPhoneNumberRequestTests.m
index 9719d4f..b1ceaf4 100644
--- a/Example/Auth/Tests/FIRVerifyPhoneNumberRequestTests.m
+++ b/Example/Auth/Tests/FIRVerifyPhoneNumberRequestTests.m
@@ -17,6 +17,7 @@
 #import <XCTest/XCTest.h>
 
 #import "FIRAuthBackend.h"
+#import "FIRAuthOperationType.h"
 #import "FIRVerifyPhoneNumberRequest.h"
 #import "FIRVerifyPhoneNumberResponse.h"
 #import "FIRFakeBackendRPCIssuer.h"
@@ -61,6 +62,11 @@ static NSString *const kVerificationIDKey = @"sessionInfo";
  */
 static NSString *const kIDTokenKey = @"idToken";
 
+/** @var kOperationKey
+    @brief The key for the "operation" value in the request.
+ */
+static NSString *const kOperationKey = @"operation";
+
 /** @var kTestAccessToken
     @bried Fake acess token for testing.
  */
@@ -82,6 +88,22 @@ static NSString *const kPhoneNumberKey = @"phoneNumber";
 static NSString *const kExpectedAPIURL =
     @"https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyPhoneNumber?key=APIKey";
 
+/** @Extension FIRVerifyPhoneNumberRequest
+    @brief Exposes FIRAuthOperationString from FIRVerifyPhoneNumberRequest to assist testing.
+ */
+@interface FIRVerifyPhoneNumberRequest ()
+
+/** @fn FIRAuthOperationString
+    @brief Exposes FIRAuthOperationString from FIRVerifyPhoneNumberRequest to assist testing.
+    @param operationType The value of the FIRAuthOperationType enum which will be translated to its
+        corresponding string value.
+    @return The string value corresponding to the FIRAuthOperationType argument.
+
+ */
+NSString *const FIRAuthOperationString(FIRAuthOperationType operationType);
+
+@end
+
 /** @class FIRVerifyPhoneNumberRequestTests
     @brief Tests for @c FIRVerifyPhoneNumberRequest.
  */
@@ -123,6 +145,7 @@ static NSString *const kExpectedAPIURL =
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithVerificationID:kVerificationID
                                                  verificationCode:kVerificationCode
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   request.accessToken = kTestAccessToken;
   [FIRAuthBackend verifyPhoneNumber:request
@@ -135,6 +158,8 @@ static NSString *const kExpectedAPIURL =
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kVerificationIDKey], kVerificationID);
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kVerificationCodeKey], kVerificationCode);
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kIDTokenKey], kTestAccessToken);
+  XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kOperationKey],
+                 FIRAuthOperationString(FIRAuthOperationTypeSignUpOrSignIn));
 }
 
 /** @fn testVerifyPhoneNumberRequestWithTemporaryProof
@@ -144,6 +169,7 @@ static NSString *const kExpectedAPIURL =
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithTemporaryProof:kTemporaryProof
                                                       phoneNumber:kPhoneNumber
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   request.accessToken = kTestAccessToken;
   [FIRAuthBackend verifyPhoneNumber:request
@@ -156,6 +182,8 @@ static NSString *const kExpectedAPIURL =
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kTemporaryProofKey], kTemporaryProof);
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kPhoneNumberKey], kPhoneNumber);
   XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kIDTokenKey], kTestAccessToken);
+  XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kOperationKey],
+                        FIRAuthOperationString(FIRAuthOperationTypeSignUpOrSignIn));
 }
 
 @end
diff --git a/Example/Auth/Tests/FIRVerifyPhoneNumberResponseTests.m b/Example/Auth/Tests/FIRVerifyPhoneNumberResponseTests.m
index 92110f2..0363729 100644
--- a/Example/Auth/Tests/FIRVerifyPhoneNumberResponseTests.m
+++ b/Example/Auth/Tests/FIRVerifyPhoneNumberResponseTests.m
@@ -18,6 +18,7 @@
 #import "Phone/FIRPhoneAuthCredential_Internal.h"
 #import "FIRAuthBackend.h"
 #import "FIRAuthErrors.h"
+#import "FIRAuthOperationType.h"
 #import "FIRVerifyPhoneNumberRequest.h"
 #import "FIRVerifyPhoneNumberResponse.h"
 #import "FIRFakeBackendRPCIssuer.h"
@@ -133,6 +134,7 @@ static const double kAllowedTimeDifference = 0.1;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithVerificationID:kVerificationID
                                                  verificationCode:kVerificationCode
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   __block BOOL callbackInvoked;
   __block FIRVerifyPhoneNumberResponse *RPCResponse;
@@ -161,6 +163,7 @@ static const double kAllowedTimeDifference = 0.1;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithVerificationID:kVerificationID
                                                  verificationCode:kVerificationCode
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   __block BOOL callbackInvoked;
   __block FIRVerifyPhoneNumberResponse *RPCResponse;
@@ -188,6 +191,7 @@ static const double kAllowedTimeDifference = 0.1;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithVerificationID:kVerificationID
                                                  verificationCode:kVerificationCode
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   __block BOOL callbackInvoked;
   __block FIRVerifyPhoneNumberResponse *RPCResponse;
@@ -215,6 +219,7 @@ static const double kAllowedTimeDifference = 0.1;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithVerificationID:kVerificationID
                                                  verificationCode:kVerificationCode
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   __block BOOL callbackInvoked;
   __block FIRVerifyPhoneNumberResponse *RPCResponse;
@@ -252,6 +257,7 @@ static const double kAllowedTimeDifference = 0.1;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithTemporaryProof:kFakeTemporaryProof
                                                       phoneNumber:kFakePhoneNumber
+                                                        operation:FIRAuthOperationTypeSignUpOrSignIn
                                              requestConfiguration:_requestConfiguration];
   __block BOOL callbackInvoked;
   __block FIRVerifyPhoneNumberResponse *RPCResponse;
diff --git a/Firebase/Auth/FIRAuthOperationType.h b/Firebase/Auth/FIRAuthOperationType.h
new file mode 100644
index 0000000..15d3dd7
--- /dev/null
+++ b/Firebase/Auth/FIRAuthOperationType.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+    @brief Indicates the type of operation performed for RPCs that support the operation
+        parameter.
+ */
+typedef NS_ENUM(NSInteger, FIRAuthOperationType) {
+  /** Indicates that the operation type is uspecified.
+   */
+  FIRAuthOperationTypeUnspecified = 0,
+
+  /** Indicates that the operation type is sign in or sign up.
+   */
+   FIRAuthOperationTypeSignUpOrSignIn = 1,
+
+  /** Indicates that the operation type is reauthentication.
+   */
+  FIRAuthOperationTypeReauth = 2,
+
+  /** Indicates that the operation type is update.
+   */
+  FIRAuthOperationTypeUpdate = 3,
+
+  /** Indicates that the operation type is link.
+   */
+  FIRAuthOperationTypeLink = 4,
+};
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Auth/Source/FIRAuth.m b/Firebase/Auth/Source/FIRAuth.m
index 8d29eb2..f0a069c 100644
--- a/Firebase/Auth/Source/FIRAuth.m
+++ b/Firebase/Auth/Source/FIRAuth.m
@@ -31,6 +31,7 @@
 #import "FIRAuthExceptionUtils.h"
 #import "FIRAuthGlobalWorkQueue.h"
 #import "FIRAuthKeychain.h"
+#import "FIRAuthOperationType.h"
 #import "FIRUser_Internal.h"
 #import "FirebaseAuth.h"
 #import "FIRAuthBackend.h"
@@ -600,8 +601,12 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
   if ([credential isKindOfClass:[FIRPhoneAuthCredential class]]) {
     // Special case for phone auth credentials
     FIRPhoneAuthCredential *phoneCredential = (FIRPhoneAuthCredential *)credential;
-    [self signInWithPhoneCredential:phoneCredential callback:^(FIRUser *_Nullable user,
-                                                               NSError *_Nullable error) {
+    FIRAuthOperationType operation =
+        isReauthentication ? FIRAuthOperationTypeReauth : FIRAuthOperationTypeSignUpOrSignIn;
+    [self signInWithPhoneCredential:phoneCredential
+                          operation:operation
+                           callback:^(FIRUser *_Nullable user,
+                                      NSError *_Nullable error) {
       if (callback) {
         FIRAuthDataResult *result = user ?
             [[FIRAuthDataResult alloc] initWithUser:user additionalUserInfo:nil] : nil;
@@ -1023,15 +1028,18 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
 /** @fn signInWithPhoneCredential:callback:
     @brief Signs in using a phone credential.
     @param credential The Phone Auth credential used to sign in.
+    @param operation The type of operation for which this sign-in attempt is initiated.
     @param callback A block which is invoked when the sign in finishes (or is cancelled.) Invoked
         asynchronously on the global auth work queue in the future.
  */
 - (void)signInWithPhoneCredential:(FIRPhoneAuthCredential *)credential
+                        operation:(FIRAuthOperationType)operation
                          callback:(FIRAuthResultCallback)callback {
   if (credential.temporaryProof.length && credential.phoneNumber.length) {
     FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc] initWithTemporaryProof:credential.temporaryProof
                                                       phoneNumber:credential.phoneNumber
+                                                        operation:operation
                                              requestConfiguration:_requestConfiguration];
     [self phoneNumberSignInWithRequest:request callback:callback];
     return;
@@ -1048,6 +1056,7 @@ static NSMutableDictionary *gKeychainServiceNameForAppName;
   FIRVerifyPhoneNumberRequest *request =
       [[FIRVerifyPhoneNumberRequest alloc]initWithVerificationID:credential.verificationID
                                                 verificationCode:credential.verificationCode
+                                                       operation:operation
                                             requestConfiguration:_requestConfiguration];
   [self phoneNumberSignInWithRequest:request callback:callback];
 }
diff --git a/Firebase/Auth/Source/FIRAuthOperationType.h b/Firebase/Auth/Source/FIRAuthOperationType.h
new file mode 100644
index 0000000..15d3dd7
--- /dev/null
+++ b/Firebase/Auth/Source/FIRAuthOperationType.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+    @brief Indicates the type of operation performed for RPCs that support the operation
+        parameter.
+ */
+typedef NS_ENUM(NSInteger, FIRAuthOperationType) {
+  /** Indicates that the operation type is uspecified.
+   */
+  FIRAuthOperationTypeUnspecified = 0,
+
+  /** Indicates that the operation type is sign in or sign up.
+   */
+   FIRAuthOperationTypeSignUpOrSignIn = 1,
+
+  /** Indicates that the operation type is reauthentication.
+   */
+  FIRAuthOperationTypeReauth = 2,
+
+  /** Indicates that the operation type is update.
+   */
+  FIRAuthOperationTypeUpdate = 3,
+
+  /** Indicates that the operation type is link.
+   */
+  FIRAuthOperationTypeLink = 4,
+};
+
+NS_ASSUME_NONNULL_END
diff --git a/Firebase/Auth/Source/FIRUser.m b/Firebase/Auth/Source/FIRUser.m
index 049bb30..ef42a29 100644
--- a/Firebase/Auth/Source/FIRUser.m
+++ b/Firebase/Auth/Source/FIRUser.m
@@ -27,6 +27,7 @@
 #import "FIRAuthErrorUtils.h"
 #import "FIRAuthGlobalWorkQueue.h"
 #import "FIRAuthSerialTaskQueue.h"
+#import "FIRAuthOperationType.h"
 #import "FIRAuth_Internal.h"
 #import "FIRSecureTokenService.h"
 #import "FIRUserInfoImpl.h"
@@ -615,27 +616,32 @@ static void callInMainThreadWithAuthDataResultAndError(
 }
 
 #if TARGET_OS_IOS
-/** @fn internalUpdatePhoneNumberCredential:completion:
+/** @fn internalUpdateOrLinkPhoneNumberCredential:completion:
     @brief Updates the phone number for the user. On success, the cached user profile data is
         updated.
 
     @param phoneAuthCredential The new phone number credential corresponding to the phone number
         to be added to the firebaes account, if a phone number is already linked to the account this
         new phone number will replace it.
+    @param isLinkOperation Boolean value indicating whether or not this is a link operation.
     @param completion Optionally; the block invoked when the user profile change has finished.
         Invoked asynchronously on the global work queue in the future.
  */
-- (void)internalUpdatePhoneNumberCredential:(FIRPhoneAuthCredential *)phoneAuthCredential
-                                 completion:(FIRUserProfileChangeCallback)completion {
+- (void)internalUpdateOrLinkPhoneNumberCredential:(FIRPhoneAuthCredential *)phoneAuthCredential
+                                  isLinkOperation:(BOOL)isLinkOperation
+                                       completion:(FIRUserProfileChangeCallback)completion {
   [self internalGetTokenWithCallback:^(NSString *_Nullable accessToken,
                                        NSError *_Nullable error) {
     if (error) {
       completion(error);
       return;
     }
+    FIRAuthOperationType operation =
+        isLinkOperation ? FIRAuthOperationTypeLink : FIRAuthOperationTypeUpdate;
     FIRVerifyPhoneNumberRequest *request = [[FIRVerifyPhoneNumberRequest alloc]
         initWithVerificationID:phoneAuthCredential.verificationID
               verificationCode:phoneAuthCredential.verificationCode
+                     operation:operation
           requestConfiguration:_auth.requestConfiguration];
     request.accessToken = accessToken;
     [FIRAuthBackend verifyPhoneNumber:request
@@ -661,8 +667,9 @@ static void callInMainThreadWithAuthDataResultAndError(
 - (void)updatePhoneNumberCredential:(FIRPhoneAuthCredential *)phoneAuthCredential
                          completion:(nullable FIRUserProfileChangeCallback)completion {
   dispatch_async(FIRAuthGlobalWorkQueue(), ^{
-    [self internalUpdatePhoneNumberCredential:phoneAuthCredential
-                                   completion:^(NSError *_Nullable error) {
+    [self internalUpdateOrLinkPhoneNumberCredential:phoneAuthCredential
+                                    isLinkOperation:NO
+                                         completion:^(NSError *_Nullable error) {
        callInMainThreadWithError(completion, error);
     }];
   });
@@ -856,8 +863,9 @@ static void callInMainThreadWithAuthDataResultAndError(
     #if TARGET_OS_IOS
     if ([credential isKindOfClass:[FIRPhoneAuthCredential class]]) {
       FIRPhoneAuthCredential *phoneAuthCredential = (FIRPhoneAuthCredential *)credential;
-      [self internalUpdatePhoneNumberCredential:phoneAuthCredential
-                                     completion:^(NSError *_Nullable error) {
+      [self internalUpdateOrLinkPhoneNumberCredential:phoneAuthCredential
+                                      isLinkOperation:YES
+                                           completion:^(NSError *_Nullable error) {
         if (error){
           callInMainThreadWithAuthDataResultAndError(completion, nil, error);
         } else {
diff --git a/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.h b/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.h
index b091d62..07988f1 100644
--- a/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.h
+++ b/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.h
@@ -16,6 +16,7 @@
 
 #import "FIRIdentityToolkitRequest.h"
 
+#import "FIRAuthOperationType.h"
 #import "FIRAuthRPCRequest.h"
 
 NS_ASSUME_NONNULL_BEGIN
@@ -38,15 +39,20 @@ NS_ASSUME_NONNULL_BEGIN
 @property(nonatomic, copy, nullable) NSString *accessToken;
 
 /** @var temporaryProof
-    @brief The a temporary proof code pertaining to this credentil, returned from the backend.
+    @brief The temporary proof code, previously returned from the backend.
  */
 @property(nonatomic, readonly, nonnull) NSString *temporaryProof;
 
 /** @var phoneNumber
-    @brief The a phone number pertaining to this credential, returned from the backend.
+    @brief The phone number to be verified in the request.
  */
 @property(nonatomic, readonly, nonnull) NSString *phoneNumber;
 
+/** @var operation
+    @brief The type of operation triggering this verify phone number request.
+ */
+@property(nonatomic, assign, readonly) FIRAuthOperationType operation;
+
 /** @fn initWithEndpoint:requestConfiguration:
     @brief Please use initWithVerificationID:verificationCode:requestConfiguration
  */
@@ -58,10 +64,12 @@ NS_ASSUME_NONNULL_BEGIN
     @brief Designated initializer.
     @param temporaryProof The temporary proof sent by the backed.
     @param phoneNumber The phone number associated with the credential to be signed in.
+    @param operation Indicates what operation triggered the verify phone number request.
     @param requestConfiguration An object containing configurations to be added to the request.
  */
 - (nullable instancetype)initWithTemporaryProof:(NSString *)temporaryProof
                                     phoneNumber:(NSString *)phoneNumber
+                                      operation:(FIRAuthOperationType)operation
                            requestConfiguration:(FIRAuthRequestConfiguration *)requestConfiguration
                               NS_DESIGNATED_INITIALIZER;
 
@@ -69,10 +77,12 @@ NS_ASSUME_NONNULL_BEGIN
     @brief Designated initializer.
     @param verificationID The verification ID obtained from the response of @c sendVerificationCode.
     @param verificationCode The verification code provided by the user.
+    @param operation Indicates what operation triggered the verify phone number request.
     @param requestConfiguration An object containing configurations to be added to the request.
  */
 - (nullable instancetype)initWithVerificationID:(NSString *)verificationID
                                verificationCode:(NSString *)verificationCode
+                                      operation:(FIRAuthOperationType)operation
                            requestConfiguration:(FIRAuthRequestConfiguration *)requestConfiguration
                               NS_DESIGNATED_INITIALIZER;
 
diff --git a/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.m b/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.m
index b859693..8af4c4e 100644
--- a/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.m
+++ b/Firebase/Auth/Source/RPCs/FIRVerifyPhoneNumberRequest.m
@@ -48,10 +48,16 @@ static NSString *const kTemporaryProofKey = @"temporaryProof";
  */
 static NSString *const kPhoneNumberKey = @"phoneNumber";
 
+/** @var kOperationKey
+    @brief The key for the operation value in the request.
+ */
+static NSString *const kOperationKey = @"operation";
+
 @implementation FIRVerifyPhoneNumberRequest
 
 - (nullable instancetype)initWithTemporaryProof:(NSString *)temporaryProof
                                     phoneNumber:(NSString *)phoneNumber
+                                      operation:(FIRAuthOperationType)operation
                            requestConfiguration:
                               (FIRAuthRequestConfiguration *)requestConfiguration {
   self = [super initWithEndpoint:kVerifyPhoneNumberEndPoint
@@ -59,12 +65,14 @@ static NSString *const kPhoneNumberKey = @"phoneNumber";
   if (self) {
     _temporaryProof = [temporaryProof copy];
     _phoneNumber = [phoneNumber copy];
+    _operation = operation;
   }
   return self;
 }
 
 - (nullable instancetype)initWithVerificationID:(NSString *)verificationID
                                verificationCode:(NSString *)verificationCode
+                                      operation:(FIRAuthOperationType)operation
                            requestConfiguration:
                               (FIRAuthRequestConfiguration *)requestConfiguration {
   self = [super initWithEndpoint:kVerifyPhoneNumberEndPoint
@@ -72,10 +80,32 @@ static NSString *const kPhoneNumberKey = @"phoneNumber";
   if (self) {
     _verificationID = verificationID;
     _verificationCode = verificationCode;
+    _operation = operation;
   }
   return self;
 }
 
+/** @fn FIRAuthOperationString
+    @brief Returns a string object corresponding to the provided FIRAuthOperationType value. 
+    @param operationType The value of the FIRAuthOperationType enum which will be translated to its
+        corresponding string value.
+    @return The string value corresponding to the FIRAuthOperationType argument.
+ */
+NSString *const FIRAuthOperationString(FIRAuthOperationType operationType) {
+  switch(operationType){
+    case FIRAuthOperationTypeUnspecified:
+      return @"VERIFY_OP_UNSPECIFIED";
+    case FIRAuthOperationTypeSignUpOrSignIn:
+      return @"SIGN_UP_OR_IN";
+    case FIRAuthOperationTypeReauth:
+      return @"REAUTH";
+    case FIRAuthOperationTypeLink:
+      return @"LINK";
+    case FIRAuthOperationTypeUpdate:
+      return @"UPDATE";
+  }
+}
+
 - (nullable id)unencodedHTTPRequestBodyWithError:(NSError *__autoreleasing  _Nullable *)error {
   NSMutableDictionary *postBody = [NSMutableDictionary dictionary];
   if (_verificationID) {
@@ -93,6 +123,8 @@ static NSString *const kPhoneNumberKey = @"phoneNumber";
   if (_phoneNumber) {
     postBody[kPhoneNumberKey] = _phoneNumber;
   }
+  NSString *operation = FIRAuthOperationString(_operation);
+  postBody[kOperationKey] = operation;
   return postBody;
 }