tests: Make building tests optional, although with no option to toggle them on for now

libluna/include/luna/CString.h

@@ -20,6 +20,7 @@ extern "C"
     char* strtok(char* str, const char* delim);
 
     usize wcslen(const wchar_t* str);
+    int wcscmp(const wchar_t* a, const wchar_t* b);
 
     char* strdup(const char* str);
     char* strndup(const char* str, usize max);

libluna/src/CString.cpp

@@ -64,6 +64,16 @@ extern "C"
         return *(const u8*)a - *(const u8*)b;
     }
 
+    int wcscmp(const wchar_t* a, const wchar_t* b)
+    {
+        while (*a && (*a == *b))
+        {
+            a++;
+            b++;
+        }
+        return *(const u8*)a - *(const u8*)b;
+    }
+
     int strncmp(const char* a, const char* b, usize max)
     {
         const char* s = a;

libluna/src/Utf8.cpp

@@ -35,6 +35,7 @@ static Result<bool> encode_wide_char_as_utf8(wchar_t c, char* result, usize& len
     const usize utf8_len = TRY(wide_char_length_as_utf8(c));
 
     if (utf8_len > len) { return false; } // Not enough space
+    len = utf8_len;
 
     u8* buf = (u8*)result;
 
@@ -137,9 +138,9 @@ Result<usize> Utf8StringDecoder::code_points() const
 
     while ((usize)(it - m_str) < m_byte_length)
     {
-        const usize utf8_len = TRY(utf8_char_length(*it));
-        if ((usize)(it - m_str) + utf8_len > m_byte_length) return err(EILSEQ);
-        it += utf8_len;
+        usize mb_len = m_byte_length - (usize)(it - m_str); // Remaining space
+        TRY(encode_utf8_as_wide_char(it, mb_len));
+        it += mb_len;
         len++;
     }
 

tests/CMakeLists.txt

@@ -16,5 +16,8 @@ function(luna_test SOURCE_FILE APP_NAME SETUID)
     endif()
 endfunction()
 
+if(BUILD_TESTS)
 luna_test(libluna/TestVector.cpp TestVector OFF)
 luna_test(libluna/TestBase64.cpp TestBase64 OFF)
+luna_test(libluna/TestUtf8.cpp TestUtf8 OFF)
+endif()

tests/libluna/TestUtf8.cpp

@@ -0,0 +1,141 @@
+#include <luna/CString.h>
+#include <luna/Utf8.h>
+#include <test.h>
+
+TestResult test_basic_utf8_ascii_decoding()
+{
+    wchar_t buf[20];
+
+    Utf8StringDecoder decoder("hello, world!");
+    validate(!decoder.decode(buf, sizeof(buf)).has_error());
+
+    validate(!wcscmp(buf, L"hello, world!"));
+
+    test_success;
+}
+
+TestResult test_basic_utf8_ascii_encoding()
+{
+    char buf[20];
+
+    Utf8StringEncoder encoder(L"hello, world!");
+    validate(!encoder.encode(buf, sizeof(buf)).has_error());
+
+    validate(!strcmp(buf, "hello, world!"));
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_with_non_ascii_chars()
+{
+    wchar_t buf[20];
+
+    Utf8StringDecoder decoder("¿ñ?");
+    validate(!decoder.decode(buf, sizeof(buf)).has_error());
+
+    validate(!wcscmp(buf, L"¿ñ?"));
+
+    test_success;
+}
+
+TestResult test_utf8_encoding_with_non_ascii_chars()
+{
+    char buf[20];
+
+    Utf8StringEncoder encoder(L"¿ñ?");
+    validate(!encoder.encode(buf, sizeof(buf)).has_error());
+
+    validate(!strcmp(buf, "¿ñ?"));
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_invalid_continuation_byte_at_start()
+{
+    Utf8StringDecoder decoder("\x83");
+    validate(decoder.code_points().has_error());
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_invalid_start_byte_at_continuation()
+{
+    Utf8StringDecoder decoder("\xc2\x7f");
+    validate(decoder.code_points().has_error());
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_unfinished_sequence()
+{
+    Utf8StringDecoder decoder("\xe0\x83");
+    validate(decoder.code_points().has_error());
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_invalid_bytes()
+{
+    Utf8StringDecoder decoder("\xf5\xf7");
+    validate(decoder.code_points().has_error());
+
+    test_success;
+}
+
+TestResult test_utf8_decoding_overlong_encoding()
+{
+    Utf8StringDecoder decoder("\xe0\x80\x80");
+    validate(decoder.code_points().has_error());
+
+    test_success;
+}
+
+TestResult test_utf8_decoder_calculate_code_points()
+{
+    Utf8StringDecoder decoder("¿ñ? ✨");
+    auto rc = decoder.code_points();
+    validate(!rc.has_error());
+    validate(rc.value() == 5);
+
+    test_success;
+}
+
+TestResult test_utf8_encoder_calculate_byte_length()
+{
+    Utf8StringEncoder encoder(L"¿ñ? ✨");
+    auto rc = encoder.byte_length();
+    validate(!rc.has_error());
+    validate(rc.value() == 9);
+
+    test_success;
+}
+
+TestResult test_utf8_encoder_code_points_outside_unicode()
+{
+    const wchar_t buf[] = { 0x120000, 0x000000 };
+
+    Utf8StringEncoder encoder(buf);
+    validate(encoder.byte_length().has_error());
+
+    test_success;
+}
+
+Result<void> test_main()
+{
+    test_prelude;
+
+    run_test(test_basic_utf8_ascii_decoding);
+    run_test(test_basic_utf8_ascii_encoding);
+    run_test(test_utf8_decoding_with_non_ascii_chars);
+    run_test(test_utf8_encoding_with_non_ascii_chars);
+    run_test(test_utf8_decoding_invalid_continuation_byte_at_start);
+    run_test(test_utf8_decoding_invalid_start_byte_at_continuation);
+    run_test(test_utf8_decoding_unfinished_sequence);
+    run_test(test_utf8_decoding_invalid_bytes);
+    run_test(test_utf8_decoding_overlong_encoding);
+    run_test(test_utf8_decoder_calculate_code_points);
+    run_test(test_utf8_encoder_calculate_byte_length);
+    run_test(test_utf8_encoder_code_points_outside_unicode);
+
+    return {};
+}