fix-datasegment.field will return the result in underlying type

src/nasdaq_protocols/fix/core.py

@@ -234,7 +234,8 @@ def __getitem__(self, key: str | int):
             return self.__dict__[key]
 
         try:
-            return self.values[key]
+            field_value = self.values[key]
+            return field_value.value if isinstance(field_value, Field) else field_value
         except KeyError:
             field = self.IndexedEntries[key]
             return field.default_value() if issubclass(field, Field) else None

src/nasdaq_protocols/fix/session.py

@@ -94,7 +94,7 @@ async def send_heartbeat(self):
 
     def _initialize_session(self, logon_msg):
         self.session_id.username = logon_msg.Username
-        self.sequence = count(logon_msg.Header.MsgSeqNum.value)
+        self.sequence = count(logon_msg.Header.MsgSeqNum)
         self.sender_comp_id = logon_msg.Header.SenderCompID
         self.sender_sub_id = logon_msg.Header.SenderSubID
         self.target_comp_id = logon_msg.Header.TargetCompID

tests/test_fix_core.py

@@ -550,6 +550,14 @@ def test__getattr__message__able_to_resolve_segment_fields():
     assert message.GroupContainer_2 is None
 
 
+def test__getattr__message__field_is_decayed_to_its_value():
+    message = Message_1()
+    message.Field_1_Int = 10
+
+    assert message.Field_1_Int == 10
+    assert isinstance(message.Field_1_Int, int)
+
+
 def test__getattr__message__fall_back_to_object_attributes_on_non_segment_fields():
     message = Message_1()