From a57f9645b2ebf7f85285494318a3135a140521a4 Mon Sep 17 00:00:00 2001
From: Nana Sakisaka <1901813+saki7@users.noreply.github.com>
Date: Sun, 13 Sep 2026 18:15:01 +0900
Subject: [PATCH] Add test utilities for Catch2

---
 include/iris/test/catch2.hpp    | 73 +++++++++++++++++++++++++++++++++
 include/iris/unicode/string.hpp | 40 +++++++++---------
 test/iris_test.hpp              | 16 +-------
 3 files changed, 94 insertions(+), 35 deletions(-)
 create mode 100644 include/iris/test/catch2.hpp

diff --git a/include/iris/test/catch2.hpp b/include/iris/test/catch2.hpp
new file mode 100644
index 0000000..b84ac6f
--- /dev/null
+++ b/include/iris/test/catch2.hpp
@@ -0,0 +1,73 @@
+#ifndef IRIS_ZZ_TEST_CATCH2_HPP
+#define IRIS_ZZ_TEST_CATCH2_HPP
+
+// SPDX-License-Identifier: MIT
+
+#include <iris/config.hpp> // IWYU pragma: keep
+
+#include <iris/unicode/string.hpp>
+#include <iris/string.hpp>
+
+#include <catch2/catch_test_macros.hpp>  // IWYU pragma: export
+#include <catch2/catch_tostring.hpp>
+
+#include <concepts>
+#include <type_traits>
+#include <string>
+#include <string_view>
+#include <ranges>
+#include <format>
+
+#include <cstddef> // IWYU pragma: keep
+
+template<std::formattable<char> T>
+    requires (!std::ranges::range<T>)
+struct Catch::StringMaker<T>
+{
+    static std::string convert(T const& value)
+    {
+        return std::format("{}", value);
+    }
+};
+
+template<iris::CharLike CharT, std::size_t N>
+    requires (!std::same_as<CharT, char> && !std::same_as<CharT, wchar_t>)
+struct Catch::StringMaker<CharT[N]>
+{
+    static std::string convert(CharT const (&str)[N])
+    {
+        return iris::to_string_ref(str);
+    }
+};
+
+template<iris::CharLike CharT>
+    requires (!std::same_as<CharT, char> && !std::same_as<CharT, wchar_t>)
+struct Catch::StringMaker<CharT const*>
+{
+    static std::string convert(CharT const* str)
+    {
+        return iris::to_string_ref(str);
+    }
+};
+
+template<class CharT, class TraitsT, class AllocT>
+    requires (!std::same_as<CharT, char> && !std::same_as<CharT, wchar_t>)
+struct Catch::StringMaker<std::basic_string<CharT, TraitsT, AllocT>, std::enable_if_t<Catch::is_range<std::basic_string<CharT, TraitsT, AllocT>>::value && !::Catch::Detail::IsStreamInsertable_v<std::basic_string<CharT, TraitsT, AllocT>>>>
+{
+    static std::string convert(std::basic_string<CharT, TraitsT, AllocT> const& str)
+    {
+        return iris::to_string_ref(str);
+    }
+};
+
+template<class CharT, class TraitsT>
+    requires (!std::same_as<CharT, char> && !std::same_as<CharT, wchar_t>)
+struct Catch::StringMaker<std::basic_string_view<CharT, TraitsT>, std::enable_if_t<Catch::is_range<std::basic_string_view<CharT, TraitsT>>::value && !::Catch::Detail::IsStreamInsertable_v<std::basic_string_view<CharT, TraitsT>>>>
+{
+    static std::string convert(std::basic_string_view<CharT, TraitsT> const& str)
+    {
+        return iris::to_string_ref(str);
+    }
+};
+
+#endif
diff --git a/include/iris/unicode/string.hpp b/include/iris/unicode/string.hpp
index 12e2cbf..62d738c 100644
--- a/include/iris/unicode/string.hpp
+++ b/include/iris/unicode/string.hpp
@@ -1416,22 +1416,22 @@ template<class CharT>
     requires std::same_as<CharT, char8_t>
 constexpr std::u8string_view transcode_ref(std::u8string const&&) = delete;
 
-//template<class CharT>
-//    requires (!std::same_as<CharT, char16_t>)
-//[[nodiscard]] constexpr std::basic_string<CharT> transcode_ref(std::u16string_view str)
-//{
-//    return unicode::transcode<CharT>(str);
-//}
+template<class CharT>
+    requires (!std::same_as<CharT, char16_t>)
+[[nodiscard]] constexpr std::basic_string<CharT> transcode_ref(std::u16string_view str)
+{
+    return unicode::transcode<CharT>(str);
+}
 
-//template<class CharT>
-//    requires std::same_as<CharT, char16_t>
-//[[nodiscard]] constexpr std::u16string_view transcode_ref(std::u16string_view str)
-//{
-//    return str;
-//}
-//template<class CharT>
-//    requires std::same_as<CharT, char16_t>
-//constexpr std::u16string_view transcode_ref(std::u16string const&&) = delete;
+template<class CharT>
+    requires std::same_as<CharT, char16_t>
+[[nodiscard]] constexpr std::u16string_view transcode_ref(std::u16string_view str)
+{
+    return str;
+}
+template<class CharT>
+    requires std::same_as<CharT, char16_t>
+constexpr std::u16string_view transcode_ref(std::u16string const&&) = delete;
 
 template<class CharT>
     requires (!std::same_as<CharT, char32_t>)
@@ -1486,11 +1486,11 @@ template<int = 0>
 
 // -------------------------------------------------------
 
-//template<int = 0>
-//[[nodiscard]] constexpr std::string to_string_ref(std::u16string_view str)
-//{
-//    return unicode::transcode<char>(str);
-//}
+template<int = 0>
+[[nodiscard]] constexpr std::string to_string_ref(std::u16string_view str)
+{
+    return unicode::transcode<char>(str);
+}
 
 // -------------------------------------------------------
 
diff --git a/test/iris_test.hpp b/test/iris_test.hpp
index 8b465f5..42d5ac0 100644
--- a/test/iris_test.hpp
+++ b/test/iris_test.hpp
@@ -5,20 +5,6 @@
 
 #include <iris/config.hpp> // IWYU pragma: keep
 
-#include <catch2/catch_test_macros.hpp>  // IWYU pragma: export
-#include <catch2/catch_tostring.hpp>
-
-#include <ranges>
-#include <format>
-
-template<std::formattable<char> T>
-    requires (!std::ranges::range<T>)
-struct Catch::StringMaker<T>
-{
-    static std::string convert(T const& value)
-    {
-        return std::format("{}", value);
-    }
-};
+#include <iris/test/catch2.hpp>
 
 #endif