added more tests

code/test/test_packet_capturing.py

 import unittest
 from scapy.layers.inet import IP, TCP
 from unittest.mock import patch
+from scapy.layers.l2 import Ether
 
 from src.packet_capturing import packet_handler
 
@@ -24,5 +25,34 @@ class TestPacketCapturing(unittest.TestCase):
             packet_handler(packet)
             mock_print.assert_called_with("Possible IP spoofing using private networks detected.")
 
+    def test_syn_fin(self):
+        packet = IP(src = "100.84.6.141", dst = "192.168.1.1") / TCP(dport = 80, flags = "SF") / Ether(src="00:11:22:33:44:55", dst="ff:ff:ff:ff:ff:ff")
+
+        with patch('builtins.print') as mock_print:
+            packet_handler(packet)
+            mock_print.assert_any_call("Malicious packet detected: SYN-FIN combination.")
+
+    def test_null_packet(self):
+        packet = IP(src = "100.84.6.141", dst = "192.168.1.1") / TCP(dport = 80, flags = 0) / Ether(src="00:11:22:33:44:55", dst="ff:ff:ff:ff:ff:ff")
+
+        with patch('builtins.print') as mock_print:
+            packet_handler(packet)
+            mock_print.assert_any_call("Malicious null packet found.")
+
+    def test_port_dest_check(self):
+        packet = IP(src="100.84.6.141", dst="192.168.1.1") / TCP(dport = 0, sport = 200, flags="F") / Ether(src="00:11:22:33:44:55", dst="ff:ff:ff:ff:ff:ff")
+
+        with patch('builtins.print') as mock_print:
+            packet_handler(packet)
+            mock_print.assert_any_call("Illegal packet with source or destination port 0.")
+
+    def test_port_src_check(self):
+        packet = IP(src="100.84.6.141", dst="192.168.1.1") / TCP(dport=80, sport=0, flags="F") / Ether(src="00:11:22:33:44:55", dst="ff:ff:ff:ff:ff:ff")
+
+        with patch('builtins.print') as mock_print:
+            packet_handler(packet)
+            mock_print.assert_any_call("Illegal packet with source or destination port 0.")
+
+
 if __name__ == '__main__':
     unittest.main()