replacing Auth by C++ auth implementation (#802)

* lazy replacing FST(Firebase)CredentialsProvider by (Firebase)CredentialsProvider

* lazy replacing FSTUser by User

* adding error-code parameter to TokenListener

* actually use const user& instead of pointer; also add an error util

* add HashUser and pass into the unordered_map

* use User in test

* use c++ CredentialsProvider and subclass in test

* fix unit test

* use explicit capture in lambda instead of capture all by reference

* cache currentUser explicitly when reset sync engineer test driver

* objc object should be captured by value in lambda

* replacing Auth/FSTUser by C++ auth implementation

* address changes

* replacing FSTGetTokenResult by C++ Token implementation

* address changes

* fix unintentional change in merging

* patch the change in objc Auth up-stream

* somehow, the lambda-version of set-user-change-listener does not work... fallback to block

* address changes

* fix another const& v.s. dispatch bug

* fix more const& v.s. dispatch bug  zxu123 committed

* fix a bad sync line

* address changes

* address change

* address change

* fix upstream change from merge

* fix upstream changes

* Suggested fixes for cpp/port_auth (#846)

* Get rid of MockDatastore factory

This avoids the need to statically allocate (and leak) a credentials
provider

* Use absl::make_unique

std::make_unique technically does not exist until C++14.

* #include <utility> for std::move

* Use std::future for the initial user

* fix style

1 files changed, 13 insertions, 7 deletions

diff --git a/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm b/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
index 3c80d16..059f257 100644
--- a/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
+++ b/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
@@ -16,25 +16,30 @@
 
 #import "Firestore/Example/Tests/Util/FSTIntegrationTestCase.h"
 
+#include <memory>
+#include <utility>
+
 #import <FirebaseCore/FIRLogger.h>
 #import <FirebaseFirestore/FirebaseFirestore-umbrella.h>
 #import <GRPCClient/GRPCCall+ChannelArg.h>
 #import <GRPCClient/GRPCCall+Tests.h>
 
+#include "Firestore/core/src/firebase/firestore/auth/empty_credentials_provider.h"
+#include "Firestore/core/src/firebase/firestore/model/database_id.h"
 #include "Firestore/core/src/firebase/firestore/util/autoid.h"
+#include "Firestore/core/src/firebase/firestore/util/string_apple.h"
+#include "absl/memory/memory.h"
 
 #import "Firestore/Source/API/FIRFirestore+Internal.h"
-#import "Firestore/Source/Auth/FSTEmptyCredentialsProvider.h"
 #import "Firestore/Source/Core/FSTFirestoreClient.h"
 #import "Firestore/Source/Local/FSTLevelDB.h"
 #import "Firestore/Source/Util/FSTDispatchQueue.h"
 
 #import "Firestore/Example/Tests/Util/FSTEventAccumulator.h"
 
-#include "Firestore/core/src/firebase/firestore/model/database_id.h"
-#include "Firestore/core/src/firebase/firestore/util/string_apple.h"
-
 namespace util = firebase::firestore::util;
+using firebase::firestore::auth::CredentialsProvider;
+using firebase::firestore::auth::EmptyCredentialsProvider;
 using firebase::firestore::model::DatabaseId;
 using firebase::firestore::util::CreateAutoId;
 
@@ -135,15 +140,16 @@ NS_ASSUME_NONNULL_BEGIN
   FSTDispatchQueue *workerDispatchQueue = [FSTDispatchQueue
       queueWith:dispatch_queue_create("com.google.firebase.firestore", DISPATCH_QUEUE_SERIAL)];
 
-  FSTEmptyCredentialsProvider *credentialsProvider = [[FSTEmptyCredentialsProvider alloc] init];
-
   FIRSetLoggerLevel(FIRLoggerLevelDebug);
   // HACK: FIRFirestore expects a non-nil app, but for tests we cheat.
   FIRApp *app = nil;
+  std::unique_ptr<CredentialsProvider> credentials_provider =
+      absl::make_unique<firebase::firestore::auth::EmptyCredentialsProvider>();
+
   FIRFirestore *firestore = [[FIRFirestore alloc] initWithProjectID:util::MakeStringView(projectID)
                                                            database:DatabaseId::kDefault
                                                      persistenceKey:persistenceKey
-                                                credentialsProvider:credentialsProvider
+                                                credentialsProvider:std::move(credentials_provider)
                                                 workerDispatchQueue:workerDispatchQueue
                                                         firebaseApp:app];