test: add normalize_lambda unit test

1 files changed, 52 insertions, 0 deletions

diff --git a/test/function.test.cpp b/test/function.test.cpp
new file mode 100644
index 0000000..9aca0eb
--- /dev/null
+++ b/test/function.test.cpp
@@ -0,0 +1,52 @@
+#include "util/function.hpp"
+
+#include <cstdint>
+#include <doctest/doctest.h>
+
+TEST_CASE("normalize_lamda")
+{
+	SUBCASE("Can return a function that returns a int")
+	{
+		const int number = 58;
+
+		CHECK(normalize_lambda(
+				  [number]()
+				  {
+					  return number;
+				  })() == number);
+	}
+
+	SUBCASE("Can preserve object state")
+	{
+		class Book
+		{
+		public:
+			Book() noexcept = default;
+
+			void read_page() noexcept
+			{
+				_pages_read++;
+			}
+
+			[[nodiscard]] uint32_t pages_read() const noexcept
+			{
+				return _pages_read;
+			}
+
+		private:
+			uint32_t _pages_read{0U};
+		};
+
+		auto book = Book();
+
+		book.read_page();
+		book.read_page();
+		book.read_page();
+
+		CHECK(normalize_lambda(
+				  [book]()
+				  {
+					  return book.pages_read();
+				  })() == 3);
+	}
+}