Implement Firestore DatabaseInfo and port both Database{Id,Info} C++ to the iOS code (#738)

* implement Firestore DatabaseInfo in C++

* temporary stash changes; blocking on the massive renaming of .m to .mm

* add database_info_test to project

* finish port DatabaseId and fix style, modular fixing DatabaseInfo

* port DatabaseInfo

* remove FSTDatabase{ID,Info} and their tests from project

* fix unit test

* use namespace alias

* use namespace alias, leftover

* address more changes

* refactoring to use raw pointer instead of value for property

* address changes

* remove self->

* fix style

* remove the name suffix Alloc

* fix a bug

2 files changed, 14 insertions, 53 deletions

diff --git a/Firestore/Example/Tests/Model/FSTDatabaseIDTests.mm b/Firestore/Example/Tests/Model/FSTDatabaseIDTests.mm
deleted file mode 100644
index cb1b19d..0000000
--- a/Firestore/Example/Tests/Model/FSTDatabaseIDTests.mm
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * 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 "Firestore/Source/Model/FSTDatabaseID.h"
-
-#import <XCTest/XCTest.h>
-
-NS_ASSUME_NONNULL_BEGIN
-
-@interface FSTDatabaseIDTests : XCTestCase
-@end
-
-@implementation FSTDatabaseIDTests
-
-- (void)testConstructor {
-  FSTDatabaseID *databaseID = [FSTDatabaseID databaseIDWithProject:@"p" database:@"d"];
-  XCTAssertEqualObjects(databaseID.projectID, @"p");
-  XCTAssertEqualObjects(databaseID.databaseID, @"d");
-  XCTAssertFalse([databaseID isDefaultDatabase]);
-}
-
-- (void)testDefaultDatabase {
-  FSTDatabaseID *databaseID =
-      [FSTDatabaseID databaseIDWithProject:@"p" database:kDefaultDatabaseID];
-  XCTAssertEqualObjects(databaseID.projectID, @"p");
-  XCTAssertEqualObjects(databaseID.databaseID, @"(default)");
-  XCTAssertTrue([databaseID isDefaultDatabase]);
-}
-
-@end
-
-NS_ASSUME_NONNULL_END
diff --git a/Firestore/Example/Tests/Model/FSTFieldValueTests.mm b/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
index 56b885f..52d5a4e 100644
--- a/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
+++ b/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
@@ -22,13 +22,18 @@
 #import "Firestore/Source/API/FIRFirestore+Internal.h"
 #import "Firestore/Source/API/FSTUserDataConverter.h"
 #import "Firestore/Source/Core/FSTTimestamp.h"
-#import "Firestore/Source/Model/FSTDatabaseID.h"
 #import "Firestore/Source/Model/FSTFieldValue.h"
 #import "Firestore/Source/Model/FSTPath.h"
 
 #import "Firestore/Example/Tests/API/FSTAPIHelpers.h"
 #import "Firestore/Example/Tests/Util/FSTHelpers.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::model::DatabaseId;
+
 /** Helper to wrap the values in a set of equality groups using FSTTestFieldValue(). */
 NSArray *FSTWrapGroups(NSArray *groups) {
   NSMutableArray *wrapped = [NSMutableArray array];
@@ -249,14 +254,15 @@ union DoubleBits {
 
 - (void)testWrapResourceNames {
   NSArray *values = @[
-    FSTTestRef(@"project", kDefaultDatabaseID, @"foo/bar"),
-    FSTTestRef(@"project", kDefaultDatabaseID, @"foo/baz")
+    FSTTestRef(@"project", util::WrapNSStringNoCopy(DatabaseId::kDefaultDatabaseId), @"foo/bar"),
+    FSTTestRef(@"project", util::WrapNSStringNoCopy(DatabaseId::kDefaultDatabaseId), @"foo/baz")
   ];
   for (FSTDocumentKeyReference *value in values) {
     FSTFieldValue *wrapped = FSTTestFieldValue(value);
     XCTAssertEqualObjects([wrapped class], [FSTReferenceValue class]);
     XCTAssertEqualObjects([wrapped value], value.key);
-    XCTAssertEqualObjects(((FSTDatabaseID *)wrapped).databaseID, value.databaseID);
+    XCTAssertTrue(*((FSTReferenceValue *)wrapped).databaseID ==
+                  *(const DatabaseId *)(value.databaseID));
   }
 }
 
@@ -417,6 +423,7 @@ union DoubleBits {
 }
 
 - (void)testValueEquality {
+  DatabaseId database_id = DatabaseId("project", DatabaseId::kDefaultDatabaseId);
   NSArray *groups = @[
     @[ FSTTestFieldValue(@YES), [FSTBooleanValue booleanValue:YES] ],
     @[ FSTTestFieldValue(@NO), [FSTBooleanValue booleanValue:NO] ],
@@ -459,10 +466,9 @@ union DoubleBits {
     ],
     @[ FSTTestFieldValue(FSTTestGeoPoint(1, 0)) ],
     @[
-      [FSTReferenceValue referenceValue:FSTTestDocKey(@"coll/doc1")
-                             databaseID:[FSTDatabaseID databaseIDWithProject:@"project"
-                                                                    database:kDefaultDatabaseID]],
-      FSTTestFieldValue(FSTTestRef(@"project", kDefaultDatabaseID, @"coll/doc1"))
+      [FSTReferenceValue referenceValue:FSTTestDocKey(@"coll/doc1") databaseID:&database_id],
+      FSTTestFieldValue(FSTTestRef(
+          @"project", util::WrapNSStringNoCopy(DatabaseId::kDefaultDatabaseId), @"coll/doc1"))
     ],
     @[ FSTTestRef(@"project", @"(default)", @"coll/doc2") ],
     @[ FSTTestFieldValue(@[ @"foo", @"bar" ]), FSTTestFieldValue(@[ @"foo", @"bar" ]) ],