test(agnocastlib): add unit test for EpollEventType

Signed-off-by: Takumi Jin <primenumber_2_3_5@yahoo.co.jp>

Author: ruth561

src/agnocastlib/CMakeLists.txt

@@ -130,6 +130,7 @@ if(BUILD_TESTING)
     test/unit/test_agnocast_subscription.cpp
     test/unit/test_mocked_agnocast.cpp
     test/unit/test_agnocast_executors.cpp
+    test/unit/test_agnocast_epoll_event.cpp
     test/unit/test_agnocast_epoll_update.cpp
     test/unit/test_node_topics.cpp
     test/unit/test_cie_client_utils.cpp)

src/agnocastlib/test/unit/test_agnocast_epoll_event.cpp

@@ -0,0 +1,51 @@
+#include "agnocast/agnocast_callback_info.hpp"
+#include "agnocast/agnocast_epoll_event.hpp"
+
+#include <gtest/gtest.h>
+
+#include <array>
+
+namespace agnocast
+{
+
+TEST(EpollEventDataTest, PackAndUnpackRoundTripForAllKnownTypes)
+{
+  constexpr EpollEventLocalID id = 0x12345678;
+
+  const std::array<EpollEventType, static_cast<size_t>(EpollEventType::NrEventType)> types = {
+    EpollEventType::Subscription, EpollEventType::Timer, EpollEventType::Clock,
+    EpollEventType::Shutdown};
+
+  for (auto type : types) {
+    const auto packed = pack_epoll_data(type, id);
+    const auto [unpacked_type, unpacked_id] = unpack_epoll_data(packed);
+
+    EXPECT_EQ(unpacked_type, type);
+    EXPECT_EQ(unpacked_id, id);
+  }
+}
+
+TEST(EpollEventDataTest, PackPlacesTypeInUpperBitsAndIdInLowerBits)
+{
+  constexpr auto type = EpollEventType::Shutdown;
+  constexpr EpollEventLocalID id = 0x89ABCDEF;
+
+  const auto packed = pack_epoll_data(type, id);
+
+  EXPECT_EQ(packed >> EPOLL_DATA_TYPE_SHIFT, static_cast<uint64_t>(type));
+  EXPECT_EQ(packed & static_cast<uint64_t>(EPOLL_DATA_ID_BITMASK), static_cast<uint64_t>(id));
+}
+
+TEST(EpollEventDataTest, PackAndUnpackWithMaxID)
+{
+  constexpr auto type = EpollEventType::Subscription;
+  constexpr EpollEventLocalID id = MAX_CALLBACK_INFO_ID - 1;
+
+  const auto packed = pack_epoll_data(type, id);
+  const auto [unpacked_type, unpacked_id] = unpack_epoll_data(packed);
+
+  EXPECT_EQ(unpacked_type, type);
+  EXPECT_EQ(unpacked_id, id);
+}
+
+}  // namespace agnocast