tests(core): reflection nullable trait

core/tests/CMakeLists.txt

@@ -12,6 +12,7 @@ add_executable(
     reflection/type.cpp
     reflection/traits/constructible.cpp
     reflection/traits/fields.cpp
+    reflection/traits/nullable.cpp
     reflection/external/primitives.cpp
     reflection/external/string.cpp
     reflection/external/uuid.cpp

core/tests/reflection/traits/nullable.cpp

@@ -0,0 +1,46 @@
+#include <doctest/doctest.h>
+
+#include <cubos/core/reflection/traits/nullable.hpp>
+#include <cubos/core/reflection/type.hpp>
+
+using cubos::core::reflection::NullableTrait;
+using cubos::core::reflection::reflect;
+using cubos::core::reflection::Type;
+
+namespace
+{
+    struct MyEntity
+    {
+        CUBOS_REFLECT;
+        uint32_t idx;
+        uint32_t generation;
+    };
+} // namespace
+
+CUBOS_REFLECT_IMPL(MyEntity)
+{
+    return Type::create("MyEntity")
+        .with(NullableTrait{[](const void* instance) {
+                                const auto* ent = static_cast<const MyEntity*>(instance);
+                                return ent->idx == UINT32_MAX && ent->generation == UINT32_MAX;
+                            },
+                            [](void* instance) {
+                                auto* ent = static_cast<MyEntity*>(instance);
+                                ent->idx = UINT32_MAX;
+                                ent->generation = UINT32_MAX;
+                            }});
+}
+
+TEST_CASE("reflection::NullableTrait")
+{
+    const auto& entityType = reflect<MyEntity>();
+    REQUIRE(entityType.has<NullableTrait>());
+
+    const auto& nullableTrait = entityType.get<NullableTrait>();
+
+    MyEntity ent{1, 1};
+    REQUIRE(!nullableTrait.isNull(&ent));
+
+    nullableTrait.setToNull(&ent);
+    REQUIRE(nullableTrait.isNull(&ent));
+}