}

        @Test
        void testListFiles() throws SmbException {
            // Arrange
            doReturn(new SmbFile[0]).when(smbFile).listFiles();

            // Act
            SmbFile[] files = smbFile.listFiles();

            // Assert
            assertNotNull(files);
            assertEquals(0, files.length);
        }

        @Test

        }

        @Test
        @DisplayName("listFiles with null root throws NullPointerException")
        void listFiles_withNullRoot_throwsNpe() {
            // Intent: null root is invalid input
            assertThrows(NullPointerException.class, () -> SmbEnumerationUtil.listFiles(null, "*", 0, null, null));
        }

        @Test

    // First listing should hit the server
    long start1 = System.currentTimeMillis();
    SmbFile[] files1 = dir.listFiles();
    long time1 = System.currentTimeMillis() - start1;
    
    // Second listing should use cache (much faster)
    long start2 = System.currentTimeMillis();
    SmbFile[] files2 = dir.listFiles();
    long time2 = System.currentTimeMillis() - start2;
    
    assertEquals(files1.length, files2.length);

        final List<File> fileList = new ArrayList<>(
                FileUtils.listFiles(new File(baseDir, "images"), fessConfig.getSupportedUploadedMediaExtentionsAsArray(), true));
        fileList.addAll(FileUtils.listFiles(new File(baseDir, "css"), fessConfig.getSupportedUploadedCssExtentionsAsArray(), true));
        fileList.addAll(FileUtils.listFiles(new File(baseDir, "js"), fessConfig.getSupportedUploadedJsExtentionsAsArray(), true));

            return new File[0];
        }
        final File libDir = new File(libPath);
        if (!libDir.exists()) {
            return new File[0];
        }
        return libDir.listFiles((file, name) -> name.startsWith(namePrefix));
    }

    /**
     * Gets plugin JAR files from the plugin directory that start with the specified prefix.
     *

        if (tempDir != null && tempDir.exists()) {
            deleteDirectory(tempDir);
        }
        super.tearDown();
    }

    private void deleteDirectory(File dir) {
        File[] files = dir.listFiles();
        if (files != null) {
            for (File file : files) {
                if (file.isDirectory()) {
                    deleteDirectory(file);
                } else {
                    file.delete();

                final Set<RequestData> requestDataSet = new HashSet<>();
                if (includeContent) {
                    try {
                        final FTPFile[] files = client.listFiles(ftpInfo.getParent(), FTPFileFilters.NON_NULL);
                        validateRequest(client);
                        for (final FTPFile f : files) {

                }
            } else if (file.isDirectory()) {
                final Set<RequestData> requestDataSet = new HashSet<>();
                if (includeContent) {
                    final File[] files = file.listFiles();
                    if (files != null) {
                        for (final File f : files) {
                            final String childUri = f.toURI().toASCIIString();

     */
    protected void appendJarFile(final String cpSeparator, final StringBuilder buf, final File libDir, final String basePath) {
        final File[] jarFiles = libDir.listFiles((FilenameFilter) (dir, name) -> name.toLowerCase().endsWith(".jar"));
        if (jarFiles != null) {
            for (final File file : jarFiles) {
                buf.append(cpSeparator);

  }

  private static final SuccessorsFunction<File> FILE_TREE =
      file -> {
        // check isDirectory() just because it may be faster than listFiles() on a non-directory
        if (file.isDirectory()) {
          File[] files = file.listFiles();
          if (files != null) {
            return unmodifiableList(Arrays.asList(files));
          }
        }

        return ImmutableList.of();