port Firestore SnapshotVersion in C++ (#767)

* implement SnapshotVersion and test

2 files changed, 57 insertions, 0 deletions

diff --git a/Firestore/core/test/firebase/firestore/model/CMakeLists.txt b/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
index 63ed813..282befd 100644
--- a/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
+++ b/Firestore/core/test/firebase/firestore/model/CMakeLists.txt
@@ -18,6 +18,7 @@ cc_test(
     database_id_test.cc
     field_path_test.cc
     field_value_test.cc
+    snapshot_version_test.cc
     timestamp_test.cc
     resource_path_test.cc
   DEPENDS
diff --git a/Firestore/core/test/firebase/firestore/model/snapshot_version_test.cc b/Firestore/core/test/firebase/firestore/model/snapshot_version_test.cc
new file mode 100644
index 0000000..e359f84
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/model/snapshot_version_test.cc
@@ -0,0 +1,56 @@
+/*
+ * 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/snapshot_version.h"
+
+#include "gtest/gtest.h"
+
+namespace firebase {
+namespace firestore {
+namespace model {
+
+TEST(SnapshotVersion, Getter) {
+  SnapshotVersion version(Timestamp(123, 456));
+  EXPECT_EQ(Timestamp(123, 456), version.timestamp());
+
+  const SnapshotVersion& no_version = SnapshotVersion::None();
+  EXPECT_EQ(Timestamp(), no_version.timestamp());
+}
+
+TEST(SnapshotVersion, Comparison) {
+  EXPECT_LT(SnapshotVersion::None(), SnapshotVersion(Timestamp(123, 456)));
+
+  EXPECT_LT(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(456, 123)));
+  EXPECT_GT(SnapshotVersion(Timestamp(456, 123)),
+            SnapshotVersion(Timestamp(123, 456)));
+  EXPECT_LE(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(456, 123)));
+  EXPECT_LE(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(123, 456)));
+  EXPECT_GE(SnapshotVersion(Timestamp(456, 123)),
+            SnapshotVersion(Timestamp(123, 456)));
+  EXPECT_GE(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(123, 456)));
+  EXPECT_EQ(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(123, 456)));
+  EXPECT_NE(SnapshotVersion(Timestamp(123, 456)),
+            SnapshotVersion(Timestamp(456, 123)));
+}
+
+}  //  namespace model
+}  //  namespace firestore
+}  //  namespace firebase