firebase-ios-sdk/Example/Auth/Tests/FIRPhoneAuthProviderTests.m

/*
 * 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 <GoogleToolboxForMac/GTMNSDictionary+URLArguments.h>
#import <OCMock/OCMock.h>
#import <XCTest/XCTest.h>

#import "FIRAuth.h"
#import "FIRPhoneAuthProvider.h"
#import <FirebaseCore/FIRApp.h>
#import "FIRAuth_Internal.h"
#import "FIRAuthAPNSToken.h"
#import "FIRAuthAPNSTokenManager.h"
#import "FIRAuthAppCredential.h"
#import "FIRAuthAppCredentialManager.h"
#import "FIRAuthBackend.h"
#import "FIRAuthCredential_Internal.h"
#import "FIRAuthErrorUtils.h"
#import "FIRAuthGlobalWorkQueue.h"
#import "FIRAuthNotificationManager.h"
#import "FIRAuthRequestConfiguration.h"
#import "FIRAuthUIDelegate.h"
#import "FIRAuthURLPresenter.h"
#import "FIRGetProjectConfigRequest.h"
#import "FIRGetProjectConfigResponse.h"
#import "FIRSendVerificationCodeRequest.h"
#import "FIRSendVerificationCodeResponse.h"
#import <FirebaseCore/FIROptions.h>
#import "FIRVerifyClientRequest.h"
#import "FIRVerifyClientResponse.h"
#import "OCMStubRecorder+FIRAuthUnitTests.h"
#import "Phone/FIRPhoneAuthCredential_Internal.h"

@import SafariServices;

NS_ASSUME_NONNULL_BEGIN

/** @var kTestPhoneNumber
    @brief A testing phone number.
 */
static NSString *const kTestPhoneNumber = @"55555555";

/** @var kTestInvalidPhoneNumber
    @brief An invalid testing phone number.
 */
static NSString *const kTestInvalidPhoneNumber = @"555+!*55555";

/** @var kTestVerificationID
    @brief A testing verfication ID.
 */
static NSString *const kTestVerificationID = @"verificationID";

/** @var kTestReceipt
    @brief A fake receipt for testing.
 */
static NSString *const kTestReceipt = @"receipt";

/** @var kTestSecret
    @brief A fake secret for testing.
 */
static NSString *const kTestSecret = @"secret";

/** @var kTestOldReceipt
    @brief A fake old receipt for testing.
 */
static NSString *const kTestOldReceipt = @"old_receipt";

/** @var kTestOldSecret
    @brief A fake old secret for testing.
 */
static NSString *const kTestOldSecret = @"old_secret";

/** @var kTestVerificationCode
    @brief A fake verfication code.
 */
static NSString *const kTestVerificationCode = @"verificationCode";

/** @var kFakeClientID
    @brief A fake client ID.
 */
static NSString *const kFakeClientID = @"123456.apps.googleusercontent.com";

/** @var kFakeReverseClientID
    @brief The dot-reversed version of the fake client ID.
 */
static NSString *const kFakeReverseClientID = @"com.googleusercontent.apps.123456";

/** @var kFakeBundleID
    @brief A fake bundle ID.
 */
static NSString *const kFakeBundleID = @"com.firebaseapp.example";

/** @var kFakeAPIKey
    @brief A fake API key.
 */
static NSString *const kFakeAPIKey = @"asdfghjkl";

/** @var kFakeAuthorizedDomain
    @brief A fake authorized domain for the app.
 */
static NSString *const kFakeAuthorizedDomain = @"test.firebaseapp.com";

/** @var kFakeReCAPTCHAToken
    @brief A fake reCAPTCHA token.
 */
static NSString *const kFakeReCAPTCHAToken = @"fakeReCAPTCHAToken";

/** @var kFakeRedirectURLStringWithReCAPTCHAToken
    @brief The format for a fake redirect URL string that contains the fake reCAPTCHA token above.
 */
static NSString *const kFakeRedirectURLStringWithReCAPTCHAToken = @"com.googleusercontent.apps.1"
    "23456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fcal"
    "lback%3FauthType%3DverifyApp%26recaptchaToken%3DfakeReCAPTCHAToken";

/** @var kFakeRedirectURLStringInvalidClientID
    @brief The format for a fake redirect URL string with an invalid client error.
 */
static NSString *const kFakeRedirectURLStringInvalidClientID = @"com.googleusercontent.apps.1"
    "23456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fcal"
    "lback%3FfirebaseError%3D%257B%2522code%2522%253A%2522auth%252Finvalid-oauth-client-id%2522%252"
    "C%2522message%2522%253A%2522The%2520OAuth%2520client%2520ID%2520provided%2520is%2520either%252"
    "0invalid%2520or%2520does%2520not%2520match%2520the%2520specified%2520API%2520key.%2522%257D%26"
    "authType%3DverifyApp";

/** @var kFakeRedirectURLStringWebNetworkRequestFailed
    @brief The format for a fake redirect URL string with a web network request failed error.
 */
static NSString *const kFakeRedirectURLStringWebNetworkRequestFailed = @"com.googleusercontent.apps"
    ".123456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fc"
    "allback%3FfirebaseError%3D%257B%2522code%2522%253A%2522auth%252Fnetwork-request-failed%2522%25"
    "2C%2522message%2522%253A%2522The%2520network%2520request%2520failed%2520.%2522%257D%26authType"
    "%3DverifyApp";

/** @var kFakeRedirectURLStringWebInternalError
    @brief The format for a fake redirect URL string with an internal web error.
 */
static NSString *const kFakeRedirectURLStringWebInternalError = @"com.googleusercontent.apps.1"
    "23456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fcal"
    "lback%3FfirebaseError%3D%257B%2522code%2522%253A%2522auth%252Finternal-error%2522%252C%2522mes"
    "sage%2522%253A%2522Internal%2520error%2520.%2522%257D%26authType%3DverifyApp";

/** @var kFakeRedirectURLStringUnknownError
    @brief The format for a fake redirect URL string with unknown error response.
 */
static NSString *const kFakeRedirectURLStringUnknownError = @"com.googleusercontent.apps.1"
    "23456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fcal"
    "lback%3FfirebaseError%3D%257B%2522code%2522%253A%2522auth%252Funknown-error-id%2522%252"
    "C%2522message%2522%253A%2522The%2520OAuth%2520client%2520ID%2520provided%2520is%2520either%252"
    "0invalid%2520or%2520does%2520not%2520match%2520the%2520specified%2520API%2520key.%2522%257D%26"
    "authType%3DverifyApp";

/** @var kFakeRedirectURLStringUnstructuredError
    @brief The format for a fake redirect URL string with unstructured error response.
 */
static NSString *const kFakeRedirectURLStringUnstructuredError = @"com.googleusercontent.apps.1"
    "23456://firebaseauth/link?deep_link_id=https%3A%2F%2Fexample.firebaseapp.com%2F__%2Fauth%2Fcal"
    "lback%3FfirebaseError%3D%257B%2522unstructuredcode%2522%253A%2522auth%252Funknown-error-id%2522%252"
    "C%2522unstructuredmessage%2522%253A%2522The%2520OAuth%2520client%2520ID%2520provided%2520is%2520either%252"
    "0invalid%2520or%2520does%2520not%2520match%2520the%2520specified%2520API%2520key.%2522%257D%26"
    "authType%3DverifyApp";

/** @var kTestTimeout
    @brief A fake timeout value for waiting for push notification.
 */
static const NSTimeInterval kTestTimeout = 5;

/** @var kExpectationTimeout
    @brief The maximum time waiting for expectations to fulfill.
 */
static const NSTimeInterval kExpectationTimeout = 2;

/** @class FIRPhoneAuthProviderTests
    @brief Tests for @c FIRPhoneAuthProvider
 */
@interface FIRPhoneAuthProviderTests : XCTestCase
@end

@implementation FIRPhoneAuthProviderTests {
  /** @var _mockBackend
      @brief The mock @c FIRAuthBackendImplementation .
   */
  id _mockBackend;

  /** @var _provider
      @brief The @c FIRPhoneAuthProvider instance under test.
   */
  FIRPhoneAuthProvider *_provider;

  /** @var _mockAuth
      @brief The mock @c FIRAuth instance associated with @c _provider .
   */
  id _mockAuth;

  /** @var _mockApp
      @brief The mock @c FIRApp instance associated with @c _mockAuth .
   */
  id _mockApp;

  /** @var _mockAPNSTokenManager
      @brief The mock @c FIRAuthAPNSTokenManager instance associated with @c _mockAuth .
   */
  id _mockAPNSTokenManager;

  /** @var _mockAppCredentialManager
      @brief The mock @c FIRAuthAppCredentialManager instance associated with @c _mockAuth .
   */
  id _mockAppCredentialManager;

  /** @var _mockNotificationManager
      @brief The mock @c FIRAuthNotificationManager instance associated with @c _mockAuth .
   */
  id _mockNotificationManager;

  /** @var _mockURLPresenter
      @brief The mock @c FIRAuthURLPresenter instance associated with @c _mockAuth .
   */
  id _mockURLPresenter;
}

- (void)setUp {
  [super setUp];
  _mockBackend = OCMProtocolMock(@protocol(FIRAuthBackendImplementation));
  [FIRAuthBackend setBackendImplementation:_mockBackend];
  _mockAuth = OCMClassMock([FIRAuth class]);
  _mockApp = OCMClassMock([FIRApp class]);
  OCMStub([_mockAuth app]).andReturn(_mockApp);
  id mockOptions = OCMClassMock([FIROptions class]);
  OCMStub([(FIRApp *)_mockApp options]).andReturn(mockOptions);
  OCMStub([mockOptions clientID]).andReturn(kFakeClientID);
  _mockAPNSTokenManager = OCMClassMock([FIRAuthAPNSTokenManager class]);
  OCMStub([_mockAuth tokenManager]).andReturn(_mockAPNSTokenManager);
  _mockAppCredentialManager = OCMClassMock([FIRAuthAppCredentialManager class]);
  OCMStub([_mockAuth appCredentialManager]).andReturn(_mockAppCredentialManager);
  _mockNotificationManager = OCMClassMock([FIRAuthNotificationManager class]);
  OCMStub([_mockAuth notificationManager]).andReturn(_mockNotificationManager);
  _mockURLPresenter = OCMClassMock([FIRAuthURLPresenter class]);
  OCMStub([_mockAuth authURLPresenter]).andReturn(_mockURLPresenter);
  id mockRequestConfiguration = OCMClassMock([FIRAuthRequestConfiguration class]);
  OCMStub([_mockAuth requestConfiguration]).andReturn(mockRequestConfiguration);
  OCMStub([mockRequestConfiguration APIKey]).andReturn(kFakeAPIKey);
  _provider = [FIRPhoneAuthProvider providerWithAuth:_mockAuth];
}

- (void)tearDown {
  [FIRAuthBackend setDefaultBackendImplementationWithRPCIssuer:nil];
  [super tearDown];
}

// We're still testing deprecated `verifyPhoneNumber:completion:` extensively.
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"

/** @fn testCredentialWithVerificationID
    @brief Tests the @c credentialWithToken method to make sure that it returns a valid
        FIRAuthCredential instance.
 */
- (void)testCredentialWithVerificationID {
  FIRPhoneAuthCredential *credential =
      [_provider credentialWithVerificationID:kTestVerificationID
                             verificationCode:kTestVerificationCode];
  XCTAssertEqualObjects(credential.verificationID, kTestVerificationID);
  XCTAssertEqualObjects(credential.verificationCode, kTestVerificationCode);
  XCTAssertNil(credential.temporaryProof);
  XCTAssertNil(credential.phoneNumber);
}

/** @fn testVerifyEmptyPhoneNumber
    @brief Tests a failed invocation @c verifyPhoneNumber:completion: because an empty phone
        number was provided.
 */
- (void)testVerifyEmptyPhoneNumber {
  // Empty phone number is checked on the client side so no backend RPC is mocked.
  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:@""
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertNotNil(error);
    XCTAssertEqual(error.code, FIRAuthErrorCodeMissingPhoneNumber);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
}

/** @fn testVerifyInvalidPhoneNumber
    @brief Tests a failed invocation @c verifyPhoneNumber:completion: because an invalid phone
        number was provided.
 */
- (void)testVerifyInvalidPhoneNumber {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMStub([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestReceipt secret:kTestSecret]);
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      callback(nil, [FIRAuthErrorUtils invalidPhoneNumberErrorWithMessage:nil]);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(verificationID);
    XCTAssertEqual(error.code, FIRAuthErrorCodeInvalidPhoneNumber);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
}

/** @fn testVerifyPhoneNumber
    @brief Tests a successful invocation of @c verifyPhoneNumber:completion:.
 */
- (void)testVerifyPhoneNumber {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMStub([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestReceipt secret:kTestSecret]);
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockSendVerificationCodeResponse = OCMClassMock([FIRSendVerificationCodeResponse class]);
      OCMStub([mockSendVerificationCodeResponse verificationID]).andReturn(kTestVerificationID);
      callback(mockSendVerificationCodeResponse, nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(error);
    XCTAssertEqualObjects(verificationID, kTestVerificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
}

/** @fn testVerifyPhoneNumberUIDelegate
    @brief Tests a successful invocation of @c verifyPhoneNumber:UIDelegate:completion:.
 */
- (void)testVerifyPhoneNumberUIDelegate {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                       FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
          andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `presentURL` is at index 2.
    [invocation getArgument:&unretainedArgument atIndex:2];
    NSURL *presentURL = unretainedArgument;
    XCTAssertEqualObjects(presentURL.scheme, @"https");
    XCTAssertEqualObjects(presentURL.host, kFakeAuthorizedDomain);
    XCTAssertEqualObjects(presentURL.path, @"/__/auth/handler");
    NSDictionary *params = [NSDictionary gtm_dictionaryWithHttpArgumentsString:presentURL.query];
    XCTAssertEqualObjects(params[@"ibi"], kFakeBundleID);
    XCTAssertEqualObjects(params[@"clientId"], kFakeClientID);
    XCTAssertEqualObjects(params[@"apiKey"], kFakeAPIKey);
    XCTAssertEqualObjects(params[@"authType"], @"verifyApp");
    XCTAssertNotNil(params[@"v"]);
    // `callbackMatcher` is at index 4
    [invocation getArgument:&unretainedArgument atIndex:4];
    FIRAuthURLCallbackMatcher callbackMatcher = unretainedArgument;
    NSMutableString *redirectURL =
        [NSMutableString stringWithString:kFakeRedirectURLStringWithReCAPTCHAToken];
    // Verify that the URL is rejected by the callback matcher without the event ID.
    XCTAssertFalse(callbackMatcher([NSURL URLWithString:redirectURL]));
    [redirectURL appendString:@"%26eventId%3D"];
    [redirectURL appendString:params[@"eventId"]];
    NSURLComponents *originalComponents = [[NSURLComponents alloc] initWithString:redirectURL];
    // Verify that the URL is accepted by the callback matcher with the matching event ID.
    XCTAssertTrue(callbackMatcher([originalComponents URL]));
    NSURLComponents *components = [originalComponents copy];
    components.query = @"https";
    XCTAssertFalse(callbackMatcher([components URL]));
    components = [originalComponents copy];
    components.host = @"badhost";
    XCTAssertFalse(callbackMatcher([components URL]));
    components = [originalComponents copy];
    components.path = @"badpath";
    XCTAssertFalse(callbackMatcher([components URL]));
    components = [originalComponents copy];
    components.query = @"badquery";
    XCTAssertFalse(callbackMatcher([components URL]));

    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringWithReCAPTCHAToken], nil);
    });
  });

  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertNil(request.appCredential);
    XCTAssertEqualObjects(request.reCAPTCHAToken, kFakeReCAPTCHAToken);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockSendVerificationCodeResponse = OCMClassMock([FIRSendVerificationCodeResponse class]);
      OCMStub([mockSendVerificationCodeResponse verificationID]).andReturn(kTestVerificationID);
      callback(mockSendVerificationCodeResponse, nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(error);
    XCTAssertEqualObjects(verificationID, kTestVerificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateInvalidClientID
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in an
        invalid client ID error.
 */
- (void)testVerifyPhoneNumberUIDelegateInvalidClientID {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                       FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
          andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringInvalidClientID], nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertEqual(error.code, FIRAuthErrorCodeInvalidClientID);
    XCTAssertNil(verificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateWebNetworkRequestFailed
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in a web
        network request failed error.
 */
- (void)testVerifyPhoneNumberUIDelegateNetworkRequestFailed {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                       FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
          andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringWebNetworkRequestFailed], nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertEqual(error.code, FIRAuthErrorCodeWebNetworkRequestFailed);
    XCTAssertNil(verificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateWebInternalError
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in a web
        internal error.
 */
- (void)testVerifyPhoneNumberUIDelegateWebInternalError {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                       FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
          andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringWebInternalError], nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertEqual(error.code, FIRAuthErrorCodeWebInternalError);
    XCTAssertNil(verificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateUnexpectedError
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in an
        invalid client ID.
 */
- (void)testVerifyPhoneNumberUIDelegateUnexpectedError {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                       FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
          andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringUnknownError], nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertEqual(error.code, FIRAuthErrorCodeAppVerificationUserInteractionFailure);
    XCTAssertNil(verificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateUnstructuredError
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in an
        error being surfaced with a default NSLocalizedFailureReasonErrorKey due to an unexpected
        structure of the error response.
 */
- (void)testVerifyPhoneNumberUIDelegateUnstructuredError {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
  .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ kFakeReverseClientID ] } ]);
  OCMStub([mockBundle bundleIdentifier]).andReturn(kFakeBundleID);

  // Simulate missing app token error.
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
  .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
  .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) {
    NSError *error = [NSError errorWithDomain:FIRAuthErrorDomain
                                         code:FIRAuthErrorCodeMissingAppToken
                                     userInfo:nil];
    callback(nil, error);
  });
  OCMExpect([_mockBackend getProjectConfig:[OCMArg any] callback:[OCMArg any]])
  .andCallBlock2(^(FIRGetProjectConfigRequest *request,
                   FIRGetProjectConfigResponseCallback callback) {
    XCTAssertNotNil(request);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockGetProjectConfigResponse = OCMClassMock([FIRGetProjectConfigResponse class]);
      OCMStub([mockGetProjectConfigResponse authorizedDomains]).
      andReturn(@[ kFakeAuthorizedDomain]);
      callback(mockGetProjectConfigResponse, nil);
    });
  });
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));

  // Expect view controller presentation by UIDelegate.
  OCMExpect([_mockURLPresenter presentURL:OCMOCK_ANY
                               UIDelegate:mockUIDelegate
                          callbackMatcher:OCMOCK_ANY
                               completion:OCMOCK_ANY]).andDo(^(NSInvocation *invocation) {
    __unsafe_unretained id unretainedArgument;
    // Indices 0 and 1 indicate the hidden arguments self and _cmd.
    // `completion` is at index 5
    [invocation getArgument:&unretainedArgument atIndex:5];
    FIRAuthURLPresentationCompletion completion = unretainedArgument;
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      completion([NSURL URLWithString:kFakeRedirectURLStringUnstructuredError], nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    UIDelegate:mockUIDelegate
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertEqual(error.code, FIRAuthErrorCodeAppVerificationUserInteractionFailure);
    XCTAssertNil(verificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testVerifyPhoneNumberUIDelegateRaiseException
    @brief Tests a invocation of @c verifyPhoneNumber:UIDelegate:completion: which results in an
        exception.
 */
- (void)testVerifyPhoneNumberUIDelegateRaiseException {
  id mockBundle = OCMClassMock([NSBundle class]);
  OCMStub(ClassMethod([mockBundle mainBundle])).andReturn(mockBundle);
  OCMStub([mockBundle objectForInfoDictionaryKey:@"CFBundleURLTypes"])
      .andReturn(@[ @{ @"CFBundleURLSchemes" : @[ @"badscheme" ] } ]);
  id mockUIDelegate = OCMProtocolMock(@protocol(FIRAuthUIDelegate));
  XCTAssertThrows([_provider verifyPhoneNumber:kTestPhoneNumber
                                    UIDelegate:mockUIDelegate
                                    completion:^(NSString *_Nullable verificationID,
                                                 NSError *_Nullable error) {
    XCTFail(@"Shouldn't call completion here.");
  }]);
}

/** @fn testNotForwardingNotification
    @brief Tests returning an error for the app failing to forward notification.
 */
- (void)testNotForwardingNotification {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(NO); });
  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(verificationID);
    XCTAssertEqual(error.code, FIRAuthErrorCodeNotificationNotForwarded);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockNotificationManager);
}

/** @fn testMissingAPNSToken
    @brief Tests returning an error for the app failing to provide an APNS device token.
 */
- (void)testMissingAPNSToken {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) { callback(nil, nil); });
  // Expect verify client request to the backend wth empty token.
  OCMExpect([_mockBackend verifyClient:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRVerifyClientRequest *request,
                       FIRVerifyClientResponseCallback callback) {
    XCTAssertNil(request.appToken);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      // The backend is supposed to return an error.
      callback(nil, [NSError errorWithDomain:FIRAuthErrorDomain
                                        code:FIRAuthErrorCodeMissingAppToken
                                    userInfo:nil]);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(verificationID);
    XCTAssertEqualObjects(error.domain, FIRAuthErrorDomain);
    XCTAssertEqual(error.code, FIRAuthErrorCodeMissingAppToken);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
  OCMVerifyAll(_mockAPNSTokenManager);
}

/** @fn testVerifyClient
    @brief Tests verifying client before sending verification code.
 */
- (void)testVerifyClient {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });
  OCMExpect([_mockAppCredentialManager credential]).andReturn(nil);
  NSData *data = [@"!@#$%^" dataUsingEncoding:NSUTF8StringEncoding];
  FIRAuthAPNSToken *token = [[FIRAuthAPNSToken alloc] initWithData:data
                                                              type:FIRAuthAPNSTokenTypeProd];
  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) { callback(token, nil); });
  // Expect verify client request to the backend.
  OCMExpect([_mockBackend verifyClient:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRVerifyClientRequest *request,
                       FIRVerifyClientResponseCallback callback) {
    XCTAssertEqualObjects(request.appToken, @"21402324255E");
    XCTAssertFalse(request.isSandbox);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockVerifyClientResponse = OCMClassMock([FIRVerifyClientResponse class]);
      OCMStub([mockVerifyClientResponse receipt]).andReturn(kTestReceipt);
      OCMStub([mockVerifyClientResponse suggestedTimeOutDate])
          .andReturn([NSDate dateWithTimeIntervalSinceNow:kTestTimeout]);
      callback(mockVerifyClientResponse, nil);
    });
  });
  // Mock receiving of push notification.
  OCMExpect([[_mockAppCredentialManager ignoringNonObjectArgs]
      didStartVerificationWithReceipt:OCMOCK_ANY timeout:0 callback:OCMOCK_ANY])
      .andCallIdDoubleIdBlock(^(NSString *receipt,
                                NSTimeInterval timeout,
                                FIRAuthAppCredentialCallback callback) {
    XCTAssertEqualObjects(receipt, kTestReceipt);
    // Unfortunately 'ignoringNonObjectArgs' means the real value for 'timeout' doesn't get passed
    // into the block either, so we can't verify it here.
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      callback([[FIRAuthAppCredential alloc] initWithReceipt:kTestReceipt secret:kTestSecret]);
    });
  });
  // Expect send verification code request to the backend.
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockSendVerificationCodeResponse = OCMClassMock([FIRSendVerificationCodeResponse class]);
      OCMStub([mockSendVerificationCodeResponse verificationID]).andReturn(kTestVerificationID);
      callback(mockSendVerificationCodeResponse, nil);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(error);
    XCTAssertEqualObjects(verificationID, kTestVerificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
  OCMVerifyAll(_mockAPNSTokenManager);
}

/** @fn testSendVerificationCodeFailedRetry
    @brief Tests failed retry after failing to send verification code.
 */
- (void)testSendVerificationCodeFailedRetry {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });

  // Expect twice due to null check consumes one expectation.
  OCMExpect([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestOldReceipt
                                                        secret:kTestOldSecret]);
  OCMExpect([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestOldReceipt
                                                        secret:kTestOldSecret]);
  NSData *data = [@"!@#$%^" dataUsingEncoding:NSUTF8StringEncoding];
  FIRAuthAPNSToken *token = [[FIRAuthAPNSToken alloc] initWithData:data
                                                              type:FIRAuthAPNSTokenTypeProd];

  // Expect first sendVerificationCode request to the backend, with request containing old app
  // credential.
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestOldReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestOldSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
        callback(nil, [FIRAuthErrorUtils invalidAppCredentialWithMessage:nil]);
    });
  });

  // Expect send verification code request to the backend, with request containing new app
  // credential data.
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      callback(nil, [FIRAuthErrorUtils invalidAppCredentialWithMessage:nil]);
    });
  });

  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) { callback(token, nil); });
  // Expect verify client request to the backend.
  OCMExpect([_mockBackend verifyClient:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRVerifyClientRequest *request,
                       FIRVerifyClientResponseCallback callback) {
    XCTAssertEqualObjects(request.appToken, @"21402324255E");
    XCTAssertFalse(request.isSandbox);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockVerifyClientResponse = OCMClassMock([FIRVerifyClientResponse class]);
      OCMStub([mockVerifyClientResponse receipt]).andReturn(kTestReceipt);
      OCMStub([mockVerifyClientResponse suggestedTimeOutDate])
          .andReturn([NSDate dateWithTimeIntervalSinceNow:kTestTimeout]);
      callback(mockVerifyClientResponse, nil);
    });
  });

  // Mock receiving of push notification.
  OCMStub([[_mockAppCredentialManager ignoringNonObjectArgs]
      didStartVerificationWithReceipt:OCMOCK_ANY timeout:0 callback:OCMOCK_ANY])
      .andCallIdDoubleIdBlock(^(NSString *receipt,
                                NSTimeInterval timeout,
                                FIRAuthAppCredentialCallback callback) {
    XCTAssertEqualObjects(receipt, kTestReceipt);
    // Unfortunately 'ignoringNonObjectArgs' means the real value for 'timeout' doesn't get passed
    // into the block either, so we can't verify it here.
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      callback([[FIRAuthAppCredential alloc] initWithReceipt:kTestReceipt secret:kTestSecret]);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertTrue([NSThread isMainThread]);
    XCTAssertNil(verificationID);
    XCTAssertEqual(error.code, FIRAuthErrorCodeInternalError);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
  OCMVerifyAll(_mockAPNSTokenManager);
}

/** @fn testSendVerificationCodeSuccessFulRetry
    @brief Tests successful retry after failing to send verification code.
 */
- (void)testSendVerificationCodeSuccessFulRetry {
  OCMExpect([_mockNotificationManager checkNotificationForwardingWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthNotificationForwardingCallback callback) { callback(YES); });

  // Expect twice due to null check consumes one expectation.
  OCMExpect([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestOldReceipt
                                                        secret:kTestOldSecret]);
  OCMExpect([_mockAppCredentialManager credential])
      .andReturn([[FIRAuthAppCredential alloc] initWithReceipt:kTestOldReceipt
                                                        secret:kTestOldSecret]);
  NSData *data = [@"!@#$%^" dataUsingEncoding:NSUTF8StringEncoding];
  FIRAuthAPNSToken *token = [[FIRAuthAPNSToken alloc] initWithData:data
                                                              type:FIRAuthAPNSTokenTypeProd];

  // Expect first sendVerificationCode request to the backend, with request containing old app
  // credential.
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestOldReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestOldSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
        callback(nil, [FIRAuthErrorUtils invalidAppCredentialWithMessage:nil]);
    });
  });

  // Expect send verification code request to the backend, with request containing new app
  // credential data.
  OCMExpect([_mockBackend sendVerificationCode:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRSendVerificationCodeRequest *request,
                       FIRSendVerificationCodeResponseCallback callback) {
    XCTAssertEqualObjects(request.phoneNumber, kTestPhoneNumber);
    XCTAssertEqualObjects(request.appCredential.receipt, kTestReceipt);
    XCTAssertEqualObjects(request.appCredential.secret, kTestSecret);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockSendVerificationCodeResponse = OCMClassMock([FIRSendVerificationCodeResponse class]);
      OCMStub([mockSendVerificationCodeResponse verificationID]).andReturn(kTestVerificationID);
      callback(mockSendVerificationCodeResponse, nil);
    });
  });

  OCMExpect([_mockAPNSTokenManager getTokenWithCallback:OCMOCK_ANY])
      .andCallBlock1(^(FIRAuthAPNSTokenCallback callback) { callback(token, nil); });
  // Expect verify client request to the backend.
  OCMExpect([_mockBackend verifyClient:[OCMArg any] callback:[OCMArg any]])
      .andCallBlock2(^(FIRVerifyClientRequest *request,
                       FIRVerifyClientResponseCallback callback) {
    XCTAssertEqualObjects(request.appToken, @"21402324255E");
    XCTAssertFalse(request.isSandbox);
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      id mockVerifyClientResponse = OCMClassMock([FIRVerifyClientResponse class]);
      OCMStub([mockVerifyClientResponse receipt]).andReturn(kTestReceipt);
      OCMStub([mockVerifyClientResponse suggestedTimeOutDate])
          .andReturn([NSDate dateWithTimeIntervalSinceNow:kTestTimeout]);
      callback(mockVerifyClientResponse, nil);
    });
  });

  // Mock receiving of push notification.
  OCMStub([[_mockAppCredentialManager ignoringNonObjectArgs]
      didStartVerificationWithReceipt:OCMOCK_ANY timeout:0 callback:OCMOCK_ANY])
      .andCallIdDoubleIdBlock(^(NSString *receipt,
                                NSTimeInterval timeout,
                                FIRAuthAppCredentialCallback callback) {
    XCTAssertEqualObjects(receipt, kTestReceipt);
    // Unfortunately 'ignoringNonObjectArgs' means the real value for 'timeout' doesn't get passed
    // into the block either, so we can't verify it here.
    dispatch_async(FIRAuthGlobalWorkQueue(), ^() {
      callback([[FIRAuthAppCredential alloc] initWithReceipt:kTestReceipt secret:kTestSecret]);
    });
  });

  XCTestExpectation *expectation = [self expectationWithDescription:@"callback"];
  [_provider verifyPhoneNumber:kTestPhoneNumber
                    completion:^(NSString *_Nullable verificationID, NSError *_Nullable error) {
    XCTAssertNil(error);
    XCTAssertEqualObjects(verificationID, kTestVerificationID);
    [expectation fulfill];
  }];
  [self waitForExpectationsWithTimeout:kExpectationTimeout handler:nil];
  OCMVerifyAll(_mockBackend);
  OCMVerifyAll(_mockNotificationManager);
  OCMVerifyAll(_mockAppCredentialManager);
  OCMVerifyAll(_mockAPNSTokenManager);
}

#pragma clang diagnostic pop // ignored "-Wdeprecated-declarations"

@end

NS_ASSUME_NONNULL_END