aprsd/tests/packets/test_packet.py

import json
import unittest

import aprslib

from aprsd import packets
from tests import fake


class TestPacket(unittest.TestCase):
    """Test Packet base class JSON serialization."""

    def test_packet_to_json(self):
        """Test Packet.to_json() method."""
        packet = packets.Packet(
            from_call=fake.FAKE_FROM_CALLSIGN,
            to_call=fake.FAKE_TO_CALLSIGN,
            msgNo='123',
        )
        json_str = packet.to_json()
        self.assertIsInstance(json_str, str)
        # Verify it's valid JSON
        json_dict = json.loads(json_str)
        self.assertEqual(json_dict['from_call'], fake.FAKE_FROM_CALLSIGN)
        self.assertEqual(json_dict['to_call'], fake.FAKE_TO_CALLSIGN)
        self.assertEqual(json_dict['msgNo'], '123')

    def test_packet_from_dict(self):
        """Test Packet.from_dict() method."""
        packet_dict = {
            '_type': 'Packet',
            'from_call': fake.FAKE_FROM_CALLSIGN,
            'to_call': fake.FAKE_TO_CALLSIGN,
            'msgNo': '123',
        }
        packet = packets.Packet.from_dict(packet_dict)
        self.assertIsInstance(packet, packets.Packet)
        self.assertEqual(packet.from_call, fake.FAKE_FROM_CALLSIGN)
        self.assertEqual(packet.to_call, fake.FAKE_TO_CALLSIGN)
        self.assertEqual(packet.msgNo, '123')

    def test_packet_round_trip(self):
        """Test Packet round-trip: to_json -> from_dict."""
        original = packets.Packet(
            from_call=fake.FAKE_FROM_CALLSIGN,
            to_call=fake.FAKE_TO_CALLSIGN,
            msgNo='123',
            addresse=fake.FAKE_TO_CALLSIGN,
        )
        json_str = original.to_json()
        packet_dict = json.loads(json_str)
        restored = packets.Packet.from_dict(packet_dict)
        self.assertEqual(restored.from_call, original.from_call)
        self.assertEqual(restored.to_call, original.to_call)
        self.assertEqual(restored.msgNo, original.msgNo)
        self.assertEqual(restored.addresse, original.addresse)

    def test_packet_from_raw_string(self):
        """Test Packet creation from raw APRS string."""
        # Note: Base Packet is rarely used directly, but we can test with a simple message
        packet_raw = 'KFAKE>APZ100::KMINE   :Test message{123'
        packet_dict = aprslib.parse(packet_raw)
        # aprslib might not set format correctly, so set it manually
        packet_dict['format'] = 'message'
        packet = packets.factory(packet_dict)
        self.assertIsInstance(packet, packets.MessagePacket)
        # Test to_json
        json_str = packet.to_json()
        self.assertIsInstance(json_str, str)
        json_dict = json.loads(json_str)
        self.assertIn('from_call', json_dict)
        # Test from_dict round trip
        restored = packets.factory(json_dict)
        self.assertEqual(restored.from_call, packet.from_call)
        self.assertEqual(restored.to_call, packet.to_call)


class TestFactory(unittest.TestCase):
    """Tests for packets.factory() — especially the _type allowlist."""

    def test_factory_known_type_roundtrip(self):
        """factory() with a known _type deserialises correctly."""
        raw = 'KFAKE>APZ100::KMINE   :Hello{99'
        pkt_dict = aprslib.parse(raw)
        pkt_dict['format'] = 'message'
        original = packets.factory(pkt_dict)
        # Serialise to JSON dict (adds _type) then round-trip through factory
        json_dict = json.loads(original.to_json())
        self.assertIn('_type', json_dict)
        restored = packets.factory(json_dict)
        self.assertIsInstance(restored, packets.MessagePacket)
        self.assertEqual(restored.from_call, original.from_call)

    def test_factory_unknown_type_raises(self):
        """factory() must raise ValueError for an unknown _type value.

        Regression test for the unsafe-deserialization fix: before the fix,
        globals()[raw['_type']] was called without validation, allowing any
        string from disk to look up arbitrary module-global names.
        """
        crafted = {'_type': 'os'}  # 'os' exists in module globals via imports
        with self.assertRaises(ValueError):
            packets.factory(crafted)

    def test_factory_arbitrary_string_raises(self):
        """factory() rejects completely arbitrary _type strings."""
        crafted = {'_type': 'EvilClass'}
        with self.assertRaises(ValueError):
            packets.factory(crafted)

    def test_factory_empty_type_raises(self):
        """factory() rejects an empty _type string."""
        crafted = {'_type': ''}
        with self.assertRaises(ValueError):
            packets.factory(crafted)

    def test_factory_allowlist_covers_all_type_lookup_classes(self):
        """Every class in TYPE_LOOKUP must be in the factory() allowlist."""
        from aprsd.packets.core import TYPE_LOOKUP, _known_packet_type_names

        allowlist = _known_packet_type_names()
        for cls in TYPE_LOOKUP.values():
            self.assertIn(
                cls.__name__,
                allowlist,
                f'{cls.__name__} is in TYPE_LOOKUP but missing from the allowlist',
            )