Firestore DatabaseId in C++ (#727)

* Implement DataBaseId in C++

* add database_id_test to project

* fix project

* address changes

* fix style

2 files changed, 48 insertions, 0 deletions

diff --git a/Firestore/core/test/firebase/firestore/model/CMakeLists.txt b/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
index 9153a57..0f83bf2 100644
--- a/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
+++ b/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
@@ -15,6 +15,7 @@
 cc_test(
   firebase_firestore_model_test
   SOURCES
+    database_id_test.cc
     field_value_test.cc
     timestamp_test.cc
   DEPENDS
diff --git a/Firestore/core/test/firebase/firestore/model/database_id_test.cc b/Firestore/core/test/firebase/firestore/model/database_id_test.cc
new file mode 100644
index 0000000..e9c9439
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/model/database_id_test.cc
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#include "Firestore/core/src/firebase/firestore/model/database_id.h"
+
+#include "gtest/gtest.h"
+
+namespace firebase {
+namespace firestore {
+namespace model {
+
+TEST(DatabaseId, Constructor) {
+  DatabaseId id("p", "d");
+  EXPECT_EQ("p", id.project_id());
+  EXPECT_EQ("d", id.database_id());
+  EXPECT_FALSE(id.IsDefaultDatabase());
+}
+
+TEST(DatabaseId, DefaultDb) {
+  DatabaseId id("p", DatabaseId::kDefaultDatabaseId);
+  EXPECT_EQ("p", id.project_id());
+  EXPECT_EQ(DatabaseId::kDefaultDatabaseId, id.database_id());
+  EXPECT_TRUE(id.IsDefaultDatabase());
+}
+
+TEST(DatabaseId, Comparison) {
+  EXPECT_LT(DatabaseId("a", "b"), DatabaseId("b", "a"));
+  EXPECT_LT(DatabaseId("a", "b"), DatabaseId("a", "c"));
+  EXPECT_EQ(DatabaseId("a", "b"), DatabaseId("a", "b"));
+}
+
+}  // namespace model
+}  // namespace firestore
+}  // namespace firebase