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

3 files changed, 26 insertions, 25 deletions

diff --git a/Firestore/Example/Tests/SpecTests/FSTMockDatastore.h b/Firestore/Example/Tests/SpecTests/FSTMockDatastore.h
index 5420c2e..e1ea2fb 100644
--- a/Firestore/Example/Tests/SpecTests/FSTMockDatastore.h
+++ b/Firestore/Example/Tests/SpecTests/FSTMockDatastore.h
@@ -34,8 +34,6 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @property(nonatomic) int writeStreamRequestCount;
 
-+ (instancetype)mockDatastoreWithWorkerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue;
-
 #pragma mark - Watch Stream manipulation.
 
 /** Injects an Added WatchChange containing the given targetIDs. */
diff --git a/Firestore/Example/Tests/SpecTests/FSTMockDatastore.mm b/Firestore/Example/Tests/SpecTests/FSTMockDatastore.mm
index d3c4171..6715b24 100644
--- a/Firestore/Example/Tests/SpecTests/FSTMockDatastore.mm
+++ b/Firestore/Example/Tests/SpecTests/FSTMockDatastore.mm
@@ -16,7 +16,6 @@
 
 #import "Firestore/Example/Tests/SpecTests/FSTMockDatastore.h"
 
-#import "Firestore/Source/Auth/FSTEmptyCredentialsProvider.h"
 #import "Firestore/Source/Core/FSTSnapshotVersion.h"
 #import "Firestore/Source/Local/FSTQueryData.h"
 #import "Firestore/Source/Model/FSTMutation.h"
@@ -27,10 +26,14 @@
 
 #import "Firestore/Example/Tests/Remote/FSTWatchChange+Testing.h"
 
+#include "Firestore/core/src/firebase/firestore/auth/credentials_provider.h"
+#include "Firestore/core/src/firebase/firestore/auth/empty_credentials_provider.h"
 #include "Firestore/core/src/firebase/firestore/core/database_info.h"
 #include "Firestore/core/src/firebase/firestore/model/database_id.h"
 #include "Firestore/core/src/firebase/firestore/util/string_apple.h"
 
+using firebase::firestore::auth::CredentialsProvider;
+using firebase::firestore::auth::EmptyCredentialsProvider;
 using firebase::firestore::core::DatabaseInfo;
 using firebase::firestore::model::DatabaseId;
 
@@ -44,17 +47,17 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithDatastore:(FSTMockDatastore *)datastore
               workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                      credentials:(id<FSTCredentialsProvider>)credentials
+                      credentials:(CredentialsProvider *)credentials
                        serializer:(FSTSerializerBeta *)serializer NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithDatabase:(const DatabaseInfo *)database
              workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                     credentials:(id<FSTCredentialsProvider>)credentials
+                     credentials:(CredentialsProvider *)credentials
                       serializer:(FSTSerializerBeta *)serializer NS_UNAVAILABLE;
 
 - (instancetype)initWithDatabase:(const DatabaseInfo *)database
              workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                     credentials:(id<FSTCredentialsProvider>)credentials
+                     credentials:(CredentialsProvider *)credentials
             responseMessageClass:(Class)responseMessageClass NS_UNAVAILABLE;
 
 @property(nonatomic, assign) BOOL open;
@@ -69,7 +72,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithDatastore:(FSTMockDatastore *)datastore
               workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                      credentials:(id<FSTCredentialsProvider>)credentials
+                      credentials:(CredentialsProvider *)credentials
                        serializer:(FSTSerializerBeta *)serializer {
   self = [super initWithDatabase:datastore.databaseInfo
              workerDispatchQueue:workerDispatchQueue
@@ -170,17 +173,17 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithDatastore:(FSTMockDatastore *)datastore
               workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                      credentials:(id<FSTCredentialsProvider>)credentials
+                      credentials:(CredentialsProvider *)credentials
                        serializer:(FSTSerializerBeta *)serializer NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithDatabase:(const DatabaseInfo *)database
              workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                     credentials:(id<FSTCredentialsProvider>)credentials
+                     credentials:(CredentialsProvider *)credentials
                       serializer:(FSTSerializerBeta *)serializer NS_UNAVAILABLE;
 
 - (instancetype)initWithDatabase:(const DatabaseInfo *)database
              workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                     credentials:(id<FSTCredentialsProvider>)credentials
+                     credentials:(CredentialsProvider *)credentials
             responseMessageClass:(Class)responseMessageClass NS_UNAVAILABLE;
 
 @property(nonatomic, strong, readonly) FSTMockDatastore *datastore;
@@ -193,7 +196,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithDatastore:(FSTMockDatastore *)datastore
               workerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue
-                      credentials:(id<FSTCredentialsProvider>)credentials
+                      credentials:(CredentialsProvider *)credentials
                        serializer:(FSTSerializerBeta *)serializer {
   self = [super initWithDatabase:datastore.databaseInfo
              workerDispatchQueue:workerDispatchQueue
@@ -279,24 +282,12 @@ NS_ASSUME_NONNULL_BEGIN
 
 /** Properties implemented in FSTDatastore that are nonpublic. */
 @property(nonatomic, strong, readonly) FSTDispatchQueue *workerDispatchQueue;
-@property(nonatomic, strong, readonly) id<FSTCredentialsProvider> credentials;
+@property(nonatomic, assign, readonly) CredentialsProvider *credentials;
 
 @end
 
 @implementation FSTMockDatastore
 
-+ (instancetype)mockDatastoreWithWorkerDispatchQueue:(FSTDispatchQueue *)workerDispatchQueue {
-  // This owns the DatabaseInfos since we do not have FirestoreClient instance to own them.
-  static DatabaseInfo database_info{DatabaseId{"project", "database"}, "persistence", "host",
-                                    false};
-
-  FSTEmptyCredentialsProvider *credentials = [[FSTEmptyCredentialsProvider alloc] init];
-
-  return [[FSTMockDatastore alloc] initWithDatabaseInfo:&database_info
-                                    workerDispatchQueue:workerDispatchQueue
-                                            credentials:credentials];
-}
-
 #pragma mark - Overridden FSTDatastore methods.
 
 - (FSTWatchStream *)createWatchStream {
diff --git a/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm b/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
index 1c7eadf..07dc84f 100644
--- a/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
+++ b/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
@@ -37,10 +37,16 @@
 #import "Firestore/Example/Tests/Core/FSTSyncEngine+Testing.h"
 #import "Firestore/Example/Tests/SpecTests/FSTMockDatastore.h"
 
+#include "Firestore/core/src/firebase/firestore/auth/empty_credentials_provider.h"
 #include "Firestore/core/src/firebase/firestore/auth/user.h"
+#include "Firestore/core/src/firebase/firestore/core/database_info.h"
+#include "Firestore/core/src/firebase/firestore/model/database_id.h"
 
+using firebase::firestore::auth::EmptyCredentialsProvider;
 using firebase::firestore::auth::HashUser;
 using firebase::firestore::auth::User;
+using firebase::firestore::core::DatabaseInfo;
+using firebase::firestore::model::DatabaseId;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -83,7 +89,9 @@ NS_ASSUME_NONNULL_BEGIN
   // ivar is declared as mutable.
   std::unordered_map<User, NSMutableArray<FSTOutstandingWrite *> *, HashUser> _outstandingWrites;
 
+  DatabaseInfo _databaseInfo;
   User _currentUser;
+  EmptyCredentialsProvider _credentialProvider;
 }
 
 - (instancetype)initWithPersistence:(id<FSTPersistence>)persistence
@@ -106,13 +114,17 @@ NS_ASSUME_NONNULL_BEGIN
 
     _events = [NSMutableArray array];
 
+    _databaseInfo = {DatabaseId{"project", "database"}, "persistence", "host", false};
+
     // Set up the sync engine and various stores.
     dispatch_queue_t mainQueue = dispatch_get_main_queue();
     FSTDispatchQueue *dispatchQueue = [FSTDispatchQueue queueWith:mainQueue];
     _localStore = [[FSTLocalStore alloc] initWithPersistence:persistence
                                             garbageCollector:garbageCollector
                                                  initialUser:initialUser];
-    _datastore = [FSTMockDatastore mockDatastoreWithWorkerDispatchQueue:dispatchQueue];
+    _datastore = [[FSTMockDatastore alloc] initWithDatabaseInfo:&_databaseInfo
+                                            workerDispatchQueue:dispatchQueue
+                                                    credentials:&_credentialProvider];
 
     _remoteStore = [FSTRemoteStore remoteStoreWithLocalStore:_localStore datastore:_datastore];