text: """
      :codeauthor: Rupesh Tare <rupesht@saltstack.com>
  """
  
  import textwrap
  
  import salt.modules.ddns as ddns
  import salt.utils.json
  from tests.support.mixins import LoaderModuleMockMixin
  from tests.support.mock import MagicMock, mock_open, patch
  from tests.support.unit import TestCase, skipIf
  
  try:
      import dns.query
      import dns.tsigkeyring
  
      HAS_DNS = True
  except ImportError:
      HAS_DNS = False
  
  
  @skipIf(HAS_DNS is False, "dnspython libs not installed")
  class DDNSTestCase(TestCase, LoaderModuleMockMixin):
      """
      TestCase for the salt.modules.ddns module
      """
  
      def setup_loader_modules(self):
          return {ddns: {}}
  
      def test_add_host(self):
          """
          Test cases for Add, replace, or update the A
          and PTR (reverse) records for a host.
          """
          with patch("salt.modules.ddns.update") as ddns_update:
              ddns_update.return_value = False
              self.assertFalse(ddns.add_host(zone="A", name="B", ttl=1, ip="172.27.0.0"))
  
              ddns_update.return_value = True
              self.assertTrue(ddns.add_host(zone="A", name="B", ttl=1, ip="172.27.0.0"))
  
      def test_delete_host(self):
          """
          Tests for delete the forward and reverse records for a host.
          """
          with patch("salt.modules.ddns.delete") as ddns_delete:
              ddns_delete.return_value = False
              with patch.object(dns.query, "udp") as mock:
                  mock.answer = [{"address": "localhost"}]
                  self.assertFalse(ddns.delete_host(zone="A", name="B"))
  
      def test_update(self):
          """
          Test to add, replace, or update a DNS record.
          """
          mock_request = textwrap.dedent(
              """\
              id 29380
              opcode QUERY
              rcode NOERROR
              flags RD
              ;QUESTION
              name.zone. IN AAAA
              ;ANSWER
              ;AUTHORITY
              ;ADDITIONAL"""
          )
          mock_rdtype = 28  # rdtype of AAAA record
  
          class MockRrset:
              def __init__(self):
                  self.items = [{"address": "localhost"}]
                  self.ttl = 2
  
          class MockAnswer:
              def __init__(self, *args, **kwargs):
                  self.answer = [MockRrset()]
  
              def rcode(self):
                  return 0
  
          def mock_udp_query(*args, **kwargs):
              return MockAnswer
  
          with patch.object(
              dns.message, "make_query", MagicMock(return_value=mock_request)
          ):
              with patch.object(dns.query, "udp", mock_udp_query()):
                  with patch.object(
                      dns.rdatatype, "from_text", MagicMock(return_value=mock_rdtype)
                  ):
                      with patch.object(ddns, "_get_keyring", return_value=None):
                          with patch.object(ddns, "_config", return_value=None):
                              self.assertTrue(
                                  ddns.update("zone", "name", 1, "AAAA", "::1")
                              )
  
      def test_delete(self):
          """
          Test to delete a DNS record.
          """
          file_data = salt.utils.json.dumps({"A": "B"})
  
          class MockAnswer:
              def __init__(self, *args, **kwargs):
                  self.answer = [{"address": "localhost"}]
  
              def rcode(self):
                  return 0
  
          def mock_udp_query(*args, **kwargs):
              return MockAnswer
  
          with patch.object(dns.query, "udp", mock_udp_query()):
              with patch(
                  "salt.utils.files.fopen", mock_open(read_data=file_data), create=True
              ):
                  with patch.object(dns.tsigkeyring, "from_text", return_value=True):
                      with patch.object(ddns, "_get_keyring", return_value=None):
                          with patch.object(ddns, "_config", return_value=None):
                              self.assertTrue(ddns.delete(zone="A", name="B"))
  