🐛 bidirectional protocols might use the same indicator for both out/in

src/nasdaq_protocols/ouch/core.py

@@ -1,3 +1,5 @@
+from abc import ABC
+
 import attrs
 from nasdaq_protocols.common import Serializable, Byte, CommonMessage, logable
 
@@ -10,19 +12,19 @@
 
 
 @attrs.define(auto_attribs=True, hash=True)
-class OuchMessageId(Serializable):
+class OuchMessageId(Serializable, ABC):
     indicator: int
-    direction: str = attrs.field(default="", eq=False, hash=False)
+    direction: str = 'outgoing'
+
+    def to_bytes(self) -> tuple[int, bytes]:
+        return Byte.to_bytes(self.indicator)
 
     @classmethod
     def from_bytes(cls, bytes_: bytes) -> tuple[int, 'OuchMessageId']:
         return 1, OuchMessageId(Byte.from_bytes(bytes_)[1])
 
-    def to_bytes(self) -> tuple[int, bytes]:
-        return Byte.to_bytes(self.indicator)
-
     def __str__(self):
-        return f'indicator={self.indicator}'
+        return f'indicator={self.indicator}, direction={self.direction}'
 
 
 @attrs.define
@@ -42,8 +44,6 @@ def __init_subclass__(cls, *args, **kwargs):
 
         if all(k in kwargs for k in ['direction', 'indicator']):
             kwargs['msg_id'] = OuchMessageId(kwargs['indicator'], kwargs['direction'])
-            if kwargs['direction'] == 'incoming':
-                Message.IncomingMsgClasses.append(cls)
-            elif kwargs['direction'] == 'outgoing':
-                Message.OutgoingMsgsClasses.append(cls)
+            container = cls.IncomingMsgClasses if kwargs['direction'] == 'incoming' else cls.OutgoingMsgsClasses
+            container.append(cls)
         super().__init_subclass__(**kwargs)

tests/test_ouch_core.py

@@ -54,7 +54,7 @@ def get(key):
         return msg
 
 
-class TestOuchApp1MessageIn(App1OuchMessage, direction='incoming', indicator=3):
+class TestOuchApp1MessageIn(App1OuchMessage, direction='incoming', indicator=1):
     __test__ = False
 
     class BodyRecord(Record):
@@ -95,6 +95,17 @@ def test__from_bytes__different_indicator__decodes_correct_message():
     assert decoded_app1_msg2_out[1] == app1_msg2_out
 
 
+def test__from_bytes__same_indicator__always_decodes_only_outgoing_message():
+    # When same indicator is used for both incoming and outgoing,
+    # from client side we always want to decode from_bytes what
+    # the server is sending us...
+    # so messages marked as "outgoing" should be decoded.
+    app1_msg_out = TestOuchApp1Message1Out.get(123456789)
+
+    decoded = App1OuchMessage.from_bytes(app1_msg_out.to_bytes()[1])
+    assert isinstance(decoded[1], TestOuchApp1Message1Out)
+
+
 def test__from_bytes__same_identifier_different_apps_returns_correct_message():
     app1_msg = TestOuchApp1Message1Out.get(123456789)
     app2_msg = TestOuchApp2MessageOut.get('AB')