feat(baud-rate): Add getter to read baud rate

Also added valid tests

Signed-off-by: Bobo Bäck Engström <bobo@id8-engineering.io>

Author: Dexter9532

src/em511/em511.py

@@ -29,6 +29,8 @@ class Em511:
     DEVICE_ADDRESS_MIN_VALUE = 1
     BAUD_RATE_MIN_VALUE = 1
     BAUD_RATE_MAX_VALUE = 5
+    PARITY_MIN_VALUE = 1
+    PARITY_MAX_VALUE = 2
 
     EM511_REGISTER_V = 0x0
     EM511_REGISTER_A = 0x2
@@ -42,6 +44,7 @@ class Em511:
     EM511_REGISTER_HOUR_COUNTER = 0x2C
     EM511_REGISTER_DEVICE_ID = 0x2000
     EM511_REGISTER_BAUD_RATE = 0x2001
+    EM511_REGISTER_PARITY = 0x2002
 
     SCALE_10 = 10
     SCALE_100 = 100
@@ -331,6 +334,27 @@ def baud_rate(self) -> int:
             raise ValueError(msg)
         return value
 
+    @property
+    def parity(self) -> int:
+        """Parity.
+
+        1=None, 2=Even (default=1)
+
+        Returns:
+            Int: Current parity.
+
+        Raises:
+            ValueError: If input is at max value or above.
+            ValueError: If parity is out of range.
+            ModbusException: If failed to read input register.
+        """
+        regs = self._read_input_registers(self.EM511_REGISTER_PARITY, self.INT16_REG_COUNT)
+        value = self._unpack(regs, self.EM511_REGISTER_PARITY)
+        if not (self.PARITY_MIN_VALUE <= value <= self.PARITY_MAX_VALUE):
+            msg = f"Invalid parity value: {value}. Must be between 1 and 2."
+            raise ValueError(msg)
+        return value
+
     @password.setter
     def password(self, value: int) -> None:
         """Password.

src/em511/test_em511.py

@@ -400,6 +400,44 @@ def test_get_baud_rate() -> None:
         _ = meter.baud_rate
 
 
+def test_get_parity() -> None:
+    """Test Get parity."""
+    client = MagicMock()
+    mock_result = MagicMock()
+    mock_result.isError.return_value = False
+    meter = Em511(1, client)
+
+    """Test 1: should pass"""
+    mock_result.registers = [0x2]
+    client.read_input_registers.return_value = mock_result
+    value = meter.parity
+    assert value == 2
+
+    """Test 2: Should pass."""
+    mock_result.registers = [0x1]
+    client.read_input_registers.return_value = mock_result
+    value = meter.parity
+    assert value == 1
+
+    """Test 3: Should raise exception due to value not in range"""
+    mock_result.registers = [0x3]
+    client.read_input_registers.return_value = mock_result
+    with pytest.raises(ValueError, match="Invalid parity value:"):
+        _ = meter.parity
+
+    """Test 4: Should raise exception due to more registers in use than allowed."""
+    mock_result.registers = [0x1860, 0x0023, 0x5743]
+    client.read_input_registers.return_value = mock_result
+    with pytest.raises(ValueError, match="Unexpected register count:"):
+        _ = meter.parity
+
+    """Test 5: Should raise exception if input value exceeds maximum value, display shows 'EEE', 16-bit register."""
+    mock_result.registers = [0x7FFF]
+    client.read_input_registers.return_value = mock_result
+    with pytest.raises(ValueError, match="Input overflow EEE for 16-bit register: "):
+        _ = meter.parity
+
+
 def test_set_password() -> None:
     """Test Set Password."""
     client = MagicMock()