patch: Feature/pkm autodetect (#15)

tests/ascii_utils_tests.cpp

@@ -0,0 +1,20 @@
+#include <doctest/doctest.h>
+
+#include "ccm/util/AsciiUtils.hpp"
+
+using namespace ccm;
+
+TEST_SUITE("asciiLower") {
+    TEST_CASE("empty string stays empty") {
+        CHECK(asciiLower("").empty());
+    }
+
+    TEST_CASE("lowercases ASCII letters and leaves other ASCII bytes unchanged") {
+        CHECK(asciiLower("AbC123!@#") == "abc123!@#");
+    }
+
+    TEST_CASE("non-ASCII UTF-8 bytes pass through unchanged") {
+        const std::string input = "caf\u00e9";
+        CHECK(asciiLower(input) == input);
+    }
+}