string: add unit test for sprintf

Signed-off-by: Simon Rozman <simon@rozman.si>

UnitTests/string.cpp

@@ -0,0 +1,37 @@
+/*
+	SPDX-License-Identifier: MIT
+	Copyright © 2023-2024 Amebis
+*/
+
+#include "pch.hpp"
+
+using namespace std;
+#ifdef _WIN32
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+#endif
+
+namespace UnitTests
+{
+	TEST_CLASS(string)
+	{
+	public:
+		TEST_METHOD(sprintf)
+		{
+			Assert::AreEqual(L"This is a test.", stdex::sprintf(L"This is %s.", stdex::locale_default, L"a test").c_str());
+			Assert::AreEqual<size_t>(15, stdex::sprintf(L"This is %s.", stdex::locale_default, L"a test").size());
+			Assert::AreEqual("This is a test.", stdex::sprintf("This is %s.", stdex::locale_default, "a test").c_str());
+			Assert::AreEqual<size_t>(15, stdex::sprintf("This is %s.", stdex::locale_default, "a test").size());
+
+			wstring wstr;
+			std::string str;
+			for (size_t i = 0; i < 2000; i++) {
+				wstr += L"🐔Test🐮\r\n";
+				str += "🐔Test🐮\r\n";
+			}
+			Assert::AreEqual(wstr.c_str(), stdex::sprintf(L"%s", stdex::locale_default, wstr.data()).c_str());
+			Assert::AreEqual(wstr.size(), stdex::sprintf(L"%s", stdex::locale_default, wstr.data()).size());
+			Assert::AreEqual(str.c_str(), stdex::sprintf("%s", stdex::locale_utf8, str.data()).c_str());
+			Assert::AreEqual(str.size(), stdex::sprintf("%s", stdex::locale_utf8, str.data()).size());
+		}
+	};
+}