Parse request/response from payload success depends on module loading order (#158)

* Fixed #157 : Parsing payload may fail depending on module loading order

Author: pylessard

test/test_response.py

@@ -3,28 +3,32 @@
 from test.UdsTest import UdsTest
 import inspect
 
+
 class DummyServiceNormal(BaseService):
     _sid = 0x13
 
     def subfunction_id(self):
         return 0x44
 
+
 class DummyServiceNoSubunction(BaseService):
     _sid = 0x13
     _use_subfunction = False
 
+
 class DummyServiceNoResponseData(BaseService):
     _sid = 0x13
     _no_response_data = True
 
+
 class RandomClass:
     pass
 
 
 class TestResponse(UdsTest):
 
     def test_create_from_instance_ok(self):
-        response = Response(DummyServiceNormal(), code = 0x22)
+        response = Response(DummyServiceNormal(), code=0x22)
         self.assertTrue(response.valid)
         self.assertEqual(response.service.request_id(), 0x13)
         self.assertEqual(response.code, 0x22)
@@ -36,57 +40,59 @@ def test_create_from_class_ok(self):
         self.assertEqual(response.code, 0x22)
 
     def test_make_payload_basic_positive(self):
-        response = Response(DummyServiceNormal(), code = 0, data=b"\x01")
+        response = Response(DummyServiceNormal(), code=0, data=b"\x01")
         self.assertTrue(response.positive)
         self.assertTrue(response.valid)
         payload = response.get_payload()
-        self.assertEqual(b"\x53\x01", payload)	# Original ID + 0x40
+        self.assertEqual(b"\x53\x01", payload)  # Original ID + 0x40
 
     def test_make_payload_basic_negative(self):
-        response = Response(DummyServiceNormal(), code = 0x10) # General Reject
+        response = Response(DummyServiceNormal(), code=0x10)  # General Reject
         self.assertFalse(response.positive)
         self.assertTrue(response.valid)
         payload = response.get_payload()
-        self.assertEqual(b"\x7F\x13\x10", payload)	# Original ID + 0x40. 7F indicate negative
+        self.assertEqual(b"\x7F\x13\x10", payload)  # Original ID + 0x40. 7F indicate negative
 
     def test_make_payload_custom_data_negative(self):
-        response = Response(DummyServiceNormal(), code = 0x10)
+        response = Response(DummyServiceNormal(), code=0x10)
         self.assertTrue(response.valid)
         self.assertFalse(response.positive)
         response.data = b"\x12\x34\x56\x78"
         payload = response.get_payload()
         self.assertEqual(b"\x7F\x13\x10\x12\x34\x56\x78", payload)
 
     def test_from_payload_basic_positive(self):
-        payload=b'\x7E\x00'	# 0x7e = TesterPresent
+        payload = b'\x7E\x00'  # 0x7e = TesterPresent
         response = Response.from_payload(payload)
         self.assertTrue(response.valid)
         self.assertTrue(response.positive)
         self.assertEqual(response.service.response_id(), 0x7E)
         self.assertEqual(response.code, 0)
+        self.assertEqual(response.code_name, 'PositiveResponse')
 
     def test_from_payload_basic_negative(self):
-        payload=b'\x7F\x3E\x10'	# 0x3e = TesterPresent, 0x10 = General Reject
+        payload = b'\x7F\x3E\x10'  # 0x3e = TesterPresent, 0x10 = General Reject
         response = Response.from_payload(payload)
         self.assertTrue(response.valid)
         self.assertFalse(response.positive)
         self.assertEqual(response.service.response_id(), 0x7E)
-        self.assertEqual(response.code, 0x10)		
+        self.assertEqual(response.code, 0x10)
+        self.assertEqual(response.code_name, 'GeneralReject')
 
     def test_from_payload_custom_data_positive(self):
-        payload=b'\x7E\x01\x12\x34\x56\x78'	# 0x3E = TesterPresent
+        payload = b'\x7E\x01\x12\x34\x56\x78'  # 0x3E = TesterPresent
         response = Response.from_payload(payload)
         self.assertTrue(response.valid)
         self.assertTrue(response.positive)
-        self.assertEqual(response.service.response_id(), 0x7E)	
+        self.assertEqual(response.service.response_id(), 0x7E)
         self.assertEqual(response.data, b'\x01\x12\x34\x56\x78')
 
     def test_from_payload_custom_data_negative(self):
-        payload=b'\x7F\x3E\x10\x12\x34\x56\x78'	# 0x3E = TesterPresent, 0x10 = General Reject
+        payload = b'\x7F\x3E\x10\x12\x34\x56\x78'  # 0x3E = TesterPresent, 0x10 = General Reject
         response = Response.from_payload(payload)
         self.assertTrue(response.valid)
         self.assertEqual(response.service.response_id(), 0x7E)
-        self.assertEqual(response.code, 0x10)	
+        self.assertEqual(response.code, 0x10)
         self.assertEqual(response.data, b'\x12\x34\x56\x78')
 
     def test_from_empty_payload(self):
@@ -110,25 +116,25 @@ def test_str_repr(self):
 
     def test_from_input_param(self):
         with self.assertRaises(ValueError):
-            response = Response(service = "a string")	
+            response = Response(service="a string")
 
         with self.assertRaises(ValueError):
-            response = Response(service = RandomClass())	
+            response = Response(service=RandomClass())
 
         with self.assertRaises(ValueError):
-            response = Response(service=DummyServiceNormal(), code = "string")	
+            response = Response(service=DummyServiceNormal(), code="string")
 
         with self.assertRaises(ValueError):
-            response = Response(service=DummyServiceNormal(), code = -1)	
+            response = Response(service=DummyServiceNormal(), code=-1)
 
         with self.assertRaises(ValueError):
-            response = Response(service=DummyServiceNormal(), code = 0x100)
+            response = Response(service=DummyServiceNormal(), code=0x100)
 
         with self.assertRaises(ValueError):
-            response = Response(service=DummyServiceNormal(), code = 0x10, data=11)	
+            response = Response(service=DummyServiceNormal(), code=0x10, data=11)
 
     def test_all_response_code_have_version(self):
-        codes = [ member[1] for member in inspect.getmembers(Response.Code) if isinstance(member[1], int) and not member[0].startswith('_')]
+        codes = [member[1] for member in inspect.getmembers(Response.Code) if isinstance(member[1], int) and not member[0].startswith('_')]
         self.assertGreater(len(codes), 0)
         for code in codes:
             # Make sure no exception is raised
@@ -137,10 +143,10 @@ def test_all_response_code_have_version(self):
             Response.Code.is_supported_by_standard(code, 2020)
 
         # Case of known code introduced in 2020
-        self.assertFalse(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable , 2006))
-        self.assertFalse(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable , 2013))
-        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable , 2020))
+        self.assertFalse(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable, 2006))
+        self.assertFalse(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable, 2013))
+        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.ResourceTemporarilyNotAvailable, 2020))
 
-        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject , 2006))
-        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject , 2013))
-        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject , 2020))
+        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject, 2006))
+        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject, 2013))
+        self.assertTrue(Response.Code.is_supported_by_standard(Response.Code.GeneralReject, 2020))

udsoncan/BaseService.py

@@ -53,6 +53,8 @@ def response_id(cls) -> int:
 
     @staticmethod
     def __get_all_subclasses(cls) -> List[Type["BaseService"]]:
+        import udsoncan.services    # This import is required for __subclasses__ to have a value. Python never import twice the same package.
+
         # this gets all subclasses and returns a list where the "most original" subclasses are listed in front of the other subclasses
         # This enables subclasses of any BaseService outside of udsoncan.services to be available, enabling specialization of calls in
         # cases where a CAN message is similar to one found in official UDS documentation but has a different service ID

udsoncan/services/AccessTimingParameter.py

@@ -1,4 +1,5 @@
-from udsoncan import Request, Response
+from udsoncan.Request import Request
+from udsoncan.Response import Response
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/ClearDiagnosticInformation.py

@@ -1,5 +1,7 @@
 import struct
-from udsoncan import Request, Response, latest_standard
+from udsoncan import latest_standard
+from udsoncan.Request import Request
+from udsoncan.Response import Response
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/CommunicationControl.py

@@ -1,4 +1,6 @@
-from udsoncan import Request, Response, CommunicationType
+from udsoncan.Request import Request
+from udsoncan.Response import Response
+from udsoncan import CommunicationType
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode
@@ -85,7 +87,7 @@ def interpret_response(cls, response: Response) -> InterpretedResponse:
         """
         if response.data is None:
             raise InvalidResponseException(response, "No data in response")
- 
+
         if len(response.data) < 1:
             raise InvalidResponseException(response, "Response data must be at least 1 byte")
 

udsoncan/services/ControlDTCSetting.py

@@ -1,4 +1,5 @@
-from udsoncan import Request, Response
+from udsoncan.Request import Request
+from udsoncan.Response import Response
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/DiagnosticSessionControl.py

@@ -1,5 +1,7 @@
 import struct
-from udsoncan import Request, Response, latest_standard
+from udsoncan.Request import Request
+from udsoncan.Response import Response
+from udsoncan import latest_standard
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/DynamicallyDefineDataIdentifier.py

@@ -1,5 +1,7 @@
 import struct
-from udsoncan import Request, Response, DynamicDidDefinition
+from udsoncan import DynamicDidDefinition
+from udsoncan.Request import Request
+from udsoncan.Response import Response
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/ECUReset.py

@@ -1,4 +1,5 @@
-from udsoncan import Request, Response
+from udsoncan.Request import Request
+from udsoncan.Response import Response
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode

udsoncan/services/InputOutputControlByIdentifier.py

@@ -1,7 +1,8 @@
 import struct
 import math
-
-from udsoncan import Request, Response, IOMasks, IOValues, DidCodec, CodecDefinition, IOConfig, IOConfigEntry
+from udsoncan.Request import Request
+from udsoncan.Response import Response
+from udsoncan import IOMasks, IOValues, DidCodec, CodecDefinition, IOConfig, IOConfigEntry
 from udsoncan.exceptions import *
 from udsoncan.BaseService import BaseService, BaseSubfunction, BaseResponseData
 from udsoncan.ResponseCode import ResponseCode