tcp: Allow serial number to mismatch in reply (#197)

As it turns out the serial number _does not seem_ to be required in the
request packet, in order to extract data from the inverter.  This field
is present in the "header" around the TCP packet, most likely to keep
the format the same between requests and replies but is not actually
checked by the inverter before it sends back a valid reply.

By being more lenient here we can recommend - or at least request - the
community to test with a nonmatching (e.g. `0`) serial number, instead
of having to look it up on the screen or through the `javascript`
backend.

omnikinverter/tcp.py

@@ -195,10 +195,14 @@ def parse_messages(serial_number: int, data: bytes) -> dict[str, Any]:
     for (message_type, reply_serial_number, message) in _unpack_messages(
         bytearray(data)
     ):
-        if reply_serial_number != serial_number:
-            raise OmnikInverterPacketInvalidError(
-                f"Replied serial number {reply_serial_number} "
-                f"not equal to request {serial_number}"
+        if reply_serial_number != serial_number:  # pragma: no cover
+            # This is allowed as it does not seem to be required to pass the serial
+            # number in the request - though empirical testing has to point out whether
+            # the request takes longer this way.
+            LOGGER.debug(
+                "Replied serial number %s not equal to request %s",
+                reply_serial_number,
+                serial_number,
             )
 
         if message_type == MESSAGE_TYPE_INFORMATION_REPLY:

tests/test_models.py

@@ -429,18 +429,6 @@ async def test_inverter_tcp_end_marker() -> None:
     assert str(excinfo.value) == "Invalid end byte"
 
 
-async def test_inverter_tcp_reply_identical_serial() -> None:
-    """Require replied serial to be identical to the request."""
-
-    with pytest.raises(OmnikInverterPacketInvalidError) as excinfo:
-        assert tcp.parse_messages(1234, load_fixture_bytes("tcp_reply.data"))
-
-    assert (
-        str(excinfo.value)
-        == "Replied serial number 987654321 not equal to request 1234"
-    )
-
-
 async def test_inverter_tcp_known_message_type() -> None:
     """Require message type to be known."""