Reduce use of NotSupportedError in favor of NotImplementedError

Table 7 of the Open Charge Point Protocol JSON 1.6, OCPP-J 1.6 Specification lists all error codes with a short description.

* NotSupported - Requested Action is not known by receiver
* NotImplemented - Requested Action is recognized but not supported by the receiver charge_point.py:175 can indicate both problems.

This project didn't distinguished between the 2 cases and would raise a NotSupportedError in both cases.

That changes with this commit. A NotImplementedError will be raised for valid OCPP actions that are not implemented by the user.

Fixes: #493

ocpp/charge_point.py

@@ -7,7 +7,7 @@
 from dataclasses import asdict
 from typing import Dict, List, Union
 
-from ocpp.exceptions import NotSupportedError, OCPPError
+from ocpp.exceptions import NotImplementedError, NotSupportedError, OCPPError
 from ocpp.messages import Call, MessageType, unpack, validate_payload
 from ocpp.routing import create_route_map
 
@@ -79,6 +79,39 @@ def remove_nones(data: Union[List, Dict]) -> Union[List, Dict]:
     return data
 
 
+def _raise_key_error(action, version):
+    """
+    Checks whether a keyerror returned by _handle_call
+    is supported by the OCPP version or is simply
+    not implemented by the server/client and raises
+    the appropriate error.
+    """
+
+    from ocpp.v16.enums import Action as v16_Action
+    from ocpp.v201.enums import Action as v201_Action
+
+    if version == "1.6":
+        if hasattr(v16_Action, action):
+            raise NotImplementedError(
+                details={"cause": f"No handler for {action} registered."}
+            )
+        else:
+            raise NotSupportedError(
+                details={"cause": f"{action} not supported by OCPP{version}."}
+            )
+    elif version in ["2.0", "2.0.1"]:
+        if hasattr(v201_Action, action):
+            raise NotImplementedError(
+                details={"cause": f"No handler for {action} registered."}
+            )
+        else:
+            raise NotSupportedError(
+                details={"cause": f"{action} not supported by OCPP{version}."}
+            )
+
+    return
+
+
 class ChargePoint:
     """
     Base Element containing all the necessary OCPP1.6J messages for messages
@@ -165,17 +198,17 @@ async def _handle_call(self, msg):
 
         First the '_on_action' hook is executed and its response is returned to
         the client. If there is no '_on_action' hook for Action in the message
-        a CallError with a NotSupportedError is returned.
+        a CallError with a NotImplementedError is returned. If the Action is
+        not supported by the OCPP version a NotSupportedError is returned.
 
         Next the '_after_action' hook is executed.
 
         """
         try:
             handlers = self.route_map[msg.action]
         except KeyError:
-            raise NotSupportedError(
-                details={"cause": f"No handler for {msg.action} registered."}
-            )
+            _raise_key_error(msg.action, self._ocpp_version)
+            return
 
         if not handlers.get("_skip_schema_validation", False):
             validate_payload(msg, self._ocpp_version)
@@ -190,9 +223,7 @@ async def _handle_call(self, msg):
         try:
             handler = handlers["_on_action"]
         except KeyError:
-            raise NotSupportedError(
-                details={"cause": f"No handler for {msg.action} registered."}
-            )
+            _raise_key_error(msg.action, self._ocpp_version)
 
         try:
             response = handler(**snake_case_payload)

ocpp/exceptions.py

@@ -35,14 +35,14 @@ def __str__(self):
 
 class NotImplementedError(OCPPError):
     code = "NotImplemented"
-    default_description = "Requested Action is not known by receiver"
+    default_description = (
+        "Request Action is recognized but not supported by the receiver"
+    )
 
 
 class NotSupportedError(OCPPError):
     code = "NotSupported"
-    default_description = (
-        "Request Action is recognized but not supported by " "the receiver"
-    )
+    default_description = "Requested Action is not known by receiver"
 
 
 class InternalError(OCPPError):

tests/v16/conftest.py

@@ -17,6 +17,11 @@ def heartbeat_call():
     return Call(unique_id=1, action=Action.Heartbeat, payload={}).to_json()
 
 
+@pytest.fixture
+def not_supported_call():
+    return Call(unique_id=1, action="InvalidAction", payload={}).to_json()
+
+
 @pytest.fixture
 def boot_notification_call():
     return Call(

tests/v16/test_v16_charge_point.py

@@ -108,6 +108,43 @@ def on_boot_notification(**kwargs):  # noqa
     )
 
 
+@pytest.mark.asyncio
+async def test_route_message_not_supported(base_central_system, not_supported_call):
+    """
+    Test that a CALLERROR is sent back, reporting that it is
+    not supported by OCPP version.
+
+    """
+
+    @on(Action.BootNotification)
+    def on_boot_notification(**kwargs):  # noqa
+        assert kwargs["firmware_version"] == "#1:3.4.0-2990#N:217H;1.0-223"
+
+        return call_result.BootNotificationPayload(
+            current_time="2018-05-29T17:37:05.495259",
+            interval=350,
+            # 'Yolo' is not a valid value for for field status.
+            status="Yolo",
+        )
+
+    setattr(base_central_system, "on_boot_notification", on_boot_notification)
+    base_central_system.route_map = create_route_map(base_central_system)
+
+    await base_central_system.route_message(not_supported_call)
+    base_central_system._connection.send.assert_called_once_with(
+        json.dumps(
+            [
+                4,
+                1,
+                "NotSupported",
+                "Requested Action is not known by receiver",
+                {"cause": "InvalidAction not supported by OCPP1.6."},
+            ],
+            separators=(",", ":"),
+        )
+    )
+
+
 @pytest.mark.asyncio
 async def test_route_message_with_no_route(base_central_system, heartbeat_call):
     """
@@ -124,7 +161,7 @@ async def test_route_message_with_no_route(base_central_system, heartbeat_call):
             [
                 4,
                 1,
-                "NotSupported",
+                "NotImplemented",
                 "Request Action is recognized but not supported by the receiver",
                 {"cause": "No handler for Heartbeat registered."},
             ],

tests/v20/test_v20_charge_point.py

@@ -76,7 +76,7 @@ async def test_route_message_with_no_route(base_central_system, heartbeat_call):
             [
                 4,
                 1,
-                "NotSupported",
+                "NotImplemented",
                 "Request Action is recognized but not supported by the receiver",
                 {"cause": "No handler for Heartbeat registered."},
             ],

tests/v201/test_v201_charge_point.py

@@ -76,7 +76,7 @@ async def test_route_message_with_no_route(base_central_system, heartbeat_call):
             [
                 4,
                 1,
-                "NotSupported",
+                "NotImplemented",
                 "Request Action is recognized but not supported by the receiver",
                 {"cause": "No handler for Heartbeat registered."},
             ],