@Test
    @DisplayName("isSMB2 returns true/false and can throw")
    void isSMB2_variants() throws Exception {
        when(transport.isSMB2()).thenReturn(true, false);
        assertTrue(transport.isSMB2());
        assertFalse(transport.isSMB2());
        verify(transport, times(2)).isSMB2();

        doThrow(new SmbException("query failed")).when(transport).isSMB2();

    @Nested
    class CopyFileExceptions {

        private SmbTreeHandleImpl newTreeHandle(boolean isSmb2) throws Exception {
            SmbTreeHandleImpl th = mock(SmbTreeHandleImpl.class);
            lenient().when(th.isSMB2()).thenReturn(isSmb2);
            return th;
        }

        private CIFSContext ctxWithIgnore(boolean ignore) {

            // and send it as a separate request instead
            String svc = null;
            final int t = this.tid;
            request.setTid(t);

            if (!transport.isSMB2()) {
                final ServerMessageBlock req = (ServerMessageBlock) request;
                svc = this.service;
                if (svc == null) {

        lenient().when(mockTreeHandle.getConfig()).thenReturn(mockConfig);
    }

    @Test
    void testWriteSingleByte() throws IOException, CIFSException {
        // Given
        when(mockTreeHandle.isSMB2()).thenReturn(true);
        when(mockTreeHandle.getSendBufferSize()).thenReturn(65536);
        when(mockFileHandle.isValid()).thenReturn(false, true); // First false to trigger ensureOpen, then true

    private SmbPipeInputStream newStreamWithInit(boolean smb2) throws CIFSException {
        when(handle.getPipe()).thenReturn(pipe);
        // init(th) behavior inside SmbFileInputStream constructor
        when(tree.isSMB2()).thenReturn(smb2);
        when(tree.getReceiveBufferSize()).thenReturn(4096);
        when(tree.getMaximumBufferSize()).thenReturn(65535);
        when(tree.hasCapability(anyInt())).thenReturn(false);

        verify(transport, times(4)).close();
    }

    @Test
    @DisplayName("isSMB2 true and exception fallback to false")
    void isSMB2Cases() throws Exception {
        // Happy path returns true; transport exception path returns false
        when(transport.isSMB2()).thenReturn(true);
        assertTrue(handle.isSMB2());

        reset(transport);
        when(session.getTransport()).thenReturn(transport);

        SmbPipeHandleImpl handle = newHandleWithBasicStubs(0, "\\\\pipe\\\\foo");
        when(pipe.ensureTreeConnected()).thenReturn(tree);
        when(tree.acquire()).thenReturn(tree);
        when(tree.isSMB2()).thenReturn(true); // simplifies stream init
        when(tree.getReceiveBufferSize()).thenReturn(4096);

        // Act: first calls construct streams, second calls return cached

            when(mockTreeHandle.getConfig()).thenReturn(mockConfig);
        }

        @Test
        void testExists() throws SmbException, CIFSException {
            // Arrange
            when(mockTreeHandle.isSMB2()).thenReturn(false);
            SmbComQueryInformationResponse response = mock(SmbComQueryInformationResponse.class);
            when(response.getAttributes()).thenReturn(SmbConstants.ATTR_NORMAL);

    private void setupSmb2(NotifyResponse resp, byte[] fileId) throws Exception {
        when(handle.isValid()).thenReturn(true);
        when(handle.getTree()).thenReturn(tree);
        when(tree.isSMB2()).thenReturn(true);
        when(tree.getConfig()).thenReturn(mock(Configuration.class));
        when(handle.getFileId()).thenReturn(fileId);

    @Mock
    Configuration mockConfig;

    private SmbFileInputStream newStream() throws SmbException {
        // Constructor that avoids external I/O; stays in-memory
        when(mockTree.isSMB2()).thenReturn(true); // default SMB2 for simple happy-path
        return new SmbFileInputStream(mockFile, mockTree, mockHandle);
    }

    @BeforeEach
    void setUp() throws Exception {