Apply READ_ATTEMPTS to the identity read (#687)

Author: heinrich321

src/ha_addon_sunsynk_multi/a_inverter.py

@@ -153,8 +153,11 @@ async def lifecycle_attempt_recovery(self) -> None:
 
     async def read_identity(self) -> Identity:
         """Read device type, protocol, and serial via the Identity Component."""
-        # HoldingUnit duck-types ModbusUnit for FC03; SolarmanUnit is the same shape.
-        identity = Identity(self.inv.unit)  # type: ignore[arg-type]
+        # Read through Sunsynk, not self.inv.unit: same read_holding_registers
+        # signature, but with READ_ATTEMPTS retries and the serial flush.
+        # ponytail: only holds while Identity reads holding registers only. A field
+        # in another space would need the unit's read_coils/read_input_registers.
+        identity = Identity(self.inv)  # type: ignore[arg-type]
         await identity.async_update()
         self.identity = identity
         return identity

src/sunsynk/sunsynk.py

@@ -183,7 +183,8 @@ async def read_holding_registers(self, start: int, length: int) -> Sequence[int]
                     self.connection._params, ModbusSerialParams
                 ):
                     await self._flush_modbus_connection(reason=type(err).__name__)
-            except ModbusProtocolError:
+            except ModbusProtocolError as err:
+                errs.append(err)
                 _LOG.error(
                     "Read register %s x%s: protocol error [attempt %s/%s]",
                     start,

src/tests/ha_addon_sunsynk_multi/test_a_inverter.py

@@ -4,6 +4,7 @@
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
+from modbus_connection import ModbusTimeoutError
 
 from ha_addon_sunsynk_multi.a_inverter import AInverter
 from ha_addon_sunsynk_multi.a_sensor import MQTT
@@ -289,3 +290,22 @@ async def test_connect_identity_failure_includes_cause() -> None:
         await ist.connect()
 
     assert "solarman://192.168.5.30:50500" in str(raised.value)
+
+
+async def test_read_identity_retries_dropped_reply(state: InverterState) -> None:
+    """READ_ATTEMPTS must cover the identity read (regs 0-7), not only sensor reads."""
+    unit = MagicMock()
+    unit.read_holding_registers = AsyncMock(
+        side_effect=[
+            ModbusTimeoutError("no reply"),
+            # device type 6, protocol 1.4, serial "2303218594"
+            [6, 0, 0x0104, 0x3233, 0x3033, 0x3231, 0x3835, 0x3934],
+        ]
+    )
+    inv_opt = InverterOptions(modbus_id=1, ha_prefix="id", serial_nr="2303218594")
+    ss = Sunsynk(unit=unit, port="/dev/ttyUSB0", state=state, read_attempts=3)
+
+    identity = await _ist(inv_opt, ss, state=state).read_identity()
+
+    assert unit.read_holding_registers.await_count == 2
+    assert identity.serial == "2303218594"

src/tests/sunsynk/test_sunsynk.py

@@ -6,6 +6,7 @@
 from unittest.mock import MagicMock, call, patch
 
 import pytest
+from modbus_connection import ModbusProtocolError
 
 from sunsynk import Sunsynk
 from sunsynk.rwsensors import NumberRWSensor
@@ -177,3 +178,14 @@ def rhr_side_effect(start: int, length: int) -> Sequence[int]:
     assert state[single] == 5
     assert state[pair] == 7 << 16
     assert state.registers == {1: 5, 10: 0, 11: 7}
+
+
+async def test_ss_protocol_error_raises_exception_group() -> None:
+    """Protocol errors must reach the ExceptionGroup, not leave it empty."""
+    unit = MagicMock()
+    unit.read_holding_registers.side_effect = ModbusProtocolError("desync")
+    ss = Sunsynk(unit=unit, read_attempts=2)  # type: ignore[arg-type]
+
+    with pytest.raises(ExceptionGroup) as excinfo:
+        await ss.read_holding_registers(622, 4)
+    assert len(excinfo.value.exceptions) == 2