@Test(expected = IOException.class)
public void testGenerateDirectoryHashNoDirectory() throws Exception {

    File rootDir = tempFolder.getRoot().getAbsoluteFile();
    File nonExistentDir = new File(rootDir, "temp");
    Utils.generateDirectoryHash(null, nonExistentDir.getAbsolutePath(), "");
    Assert.fail("Expected an IOException as the directory does not exist");
}