// An error that maps via DOS mapping
                Arguments.of(0x00000002, SmbException.getMessageByCode(0x00000002)),
                // Unknown code → hex string (uppercase)
                Arguments.of(0xDEADBEEF, "0xDEADBEEF"));
    }

    @ParameterizedTest
    @MethodSource("errorCodes")
    void constructorInitialisesMessageAndStatus(int code, String expectedMsg) {
        SmbAuthException e = new SmbAuthException(code);

    }

    @Test
    @DisplayName("Unknown DOS error code yields empty Optional")
    void testUnknownCode() {
        Optional<Integer> noMatch = findNtStatus(0xdeadbeef);
        assertFalse(noMatch.isPresent(), "Mapping for unknown code should be absent");
    }

    @Test
    @DisplayName("Mocked consumer receives correct NTSTATUS value")
    void testConsumerInteraction() {

        buf.enc_ndr_short(0); // context_id
        buf.enc_ndr_short(0); // cancel_count
        buf.enc_ndr_long(0xDEADBEEF); // fault status

        // Decode
        buf.setIndex(0);
        TestMessage m = new TestMessage();
        m.decode(buf);

        assertEquals(3, m.ptype);
        assertEquals(0xDEADBEEF, m.result);
        assertNotNull(m.getResult());
    }

    @Test

        val = ndrBuffer.dec_ndr_short();
        assertEquals(0x1234, val);
        assertEquals(4, ndrBuffer.getIndex());
    }

    @Test
    void testEncDecNdrLong() {
        ndrBuffer.enc_ndr_long(0xDEADBEEF);
        assertEquals(4, ndrBuffer.getIndex()); // Aligned to 4, then advanced by 4
        assertEquals(4, ndrBuffer.getLength());
        assertEquals((byte) 0xEF, buffer[0]); // Little-endian

        }
        request.setFileId(newFileId);
        request.setFileInfoClass((byte) 0x0A); // This will set info type to SMB2_0_INFO_FILE
        request.setAdditionalInformation(0xDEADBEEF);
        request.setQueryFlags(0xCAFEBABE);

        // Add input buffer
        Encodable mockInputBuffer = mock(Encodable.class);
        when(mockInputBuffer.size()).thenReturn(64);

    }

    @Test
    public void testInvalidProtocolId() throws Exception {
        assertThrows(SmbException.class, () -> {
            validator.validateSmbHeader(0xDEADBEEF, 64, 0x00);
        });
    }

    @Test
    public void testInvalidSmb1HeaderSize() throws Exception {
        assertThrows(SmbException.class, () -> {

        void testSpecialOffsetPatterns() {
            // Given - alternating bit pattern
            long pattern1 = 0xAAAAAAAAAAAAAAAAL;
            long pattern2 = 0x5555555555555555L;
            int pattern3 = 0xDEADBEEF;
            SrvCopychunk chunk = new SrvCopychunk(pattern1, pattern2, pattern3);
            byte[] buffer = new byte[EXPECTED_SIZE];

            // When
            int bytesWritten = chunk.encode(buffer, 0);