add LuaObject test

CMakeLists.txt

@@ -52,6 +52,7 @@ add_executable(tests
 	tests/movable.cpp
 	tests/metatables.cpp
 	tests/threads.cpp
+	tests/luaobject.cpp
 )
 
 target_link_libraries(tests

tests/luaobject.cpp

@@ -0,0 +1,30 @@
+#include <LuaContext.hpp>
+#include <gtest/gtest.h>
+
+TEST(LuaObject, RoundTripPlusRefCounting) {
+    LuaContext context;
+
+    LuaContext::LuaObject v1, v2;
+
+    context.executeCode("function regsize() local count=0 for k,v in pairs(debug.getregistry()) do count=count+1 end return count end");
+    context.executeCode("function f1() return {foo='bar'} end");
+    context.executeCode("function f2(o) return type(o) end");
+
+    auto regsize = context.readVariable<std::function<int()>>("regsize");
+
+    auto f1 = context.readVariable<std::function<LuaContext::LuaObject()>>("f1");
+    auto f2 = context.readVariable<std::function<std::string(LuaContext::LuaObject)>>("f2");
+
+    int regsize0 = regsize();
+
+    v1 = f1();
+    EXPECT_EQ("table", f2(v1));
+
+    EXPECT_EQ(regsize0 + 1, regsize());
+
+    v2 = f1();
+    EXPECT_EQ(regsize0 + 2, regsize());
+
+    v1 = v2;
+    EXPECT_EQ(regsize0 + 1, regsize());
+}