Implement CanProtocol for the SerialBus

Author: lumagi

can/interfaces/serial/serial_can.py

@@ -12,8 +12,10 @@
 import struct
 from typing import Any, List, Tuple, Optional
 
-from can import BusABC, Message
 from can import (
+    BusABC,
+    Message,
+    CanProtocol,
     CanInterfaceNotImplementedError,
     CanInitializationError,
     CanOperationError,
@@ -97,7 +99,7 @@ def __init__(
                 "could not create the serial device"
             ) from error
 
-        super().__init__(channel, *args, **kwargs)
+        super().__init__(channel, protocol=CanProtocol.CAN_20, *args, **kwargs)
 
     def shutdown(self) -> None:
         """

test/serial_test.py

@@ -11,10 +11,8 @@
 
 import can
 from can.interfaces.serial.serial_can import SerialBus
-
-from .message_helper import ComparingMessagesTestCase
 from .config import IS_PYPY
-
+from .message_helper import ComparingMessagesTestCase
 
 # Mentioned in #1010
 TIMEOUT = 0.5 if IS_PYPY else 0.1  # 0.1 is the default set in SerialBus
@@ -52,6 +50,9 @@ def __init__(self):
             self, allowed_timestamp_delta=None, preserves_channel=True
         )
 
+    def test_can_protocol(self):
+        self.assertEqual(self.bus.protocol, can.CanProtocol.CAN_20)
+
     def test_rx_tx_min_max_data(self):
         """
         Tests the transfer from 0x00 to 0xFF for a 1 byte payload