Improve parameter validation

Refactor parameter validation to handle unchanged values and re-add tests for unchanged value scenarios.

pyplumio/helpers/parameter.py

@@ -187,9 +187,6 @@ def __copy__(self) -> Parameter:
     def validate(self, value: ParameterValue) -> int:
         """Validate a parameter value."""
         value = _normalize_parameter_value(value)
-        if value == self.values.value:
-            raise ValueError("Parameter value is unchanged.")
-
         if value < self.values.min_value or value > self.values.max_value:
             raise ValueError(
                 f"Value must be between '{self.min_value}' and '{self.max_value}'"
@@ -209,6 +206,10 @@ async def _try_set(
         self, value: Any, retries: int = 5, timeout: float = 5.0
     ) -> bool:
         """Try to set a parameter value."""
+        if value == self.values.value:
+            # Value is unchanged
+            return True
+
         self._previous_value = self._values.value
         self._values.value = value
         self._pending_update = True

tests/helpers/test_parameter.py

@@ -113,9 +113,6 @@ async def test_number_validate(number: Number) -> None:
     """Test the number validation."""
     assert number.validate(2)
 
-    with pytest.raises(ValueError):
-        number.validate(1)
-
     with pytest.raises(ValueError):
         number.validate(6)
 
@@ -135,9 +132,6 @@ async def test_switch_validate(switch: Switch) -> None:
     """Test the switch validation."""
     assert switch.validate(STATE_ON)
 
-    with pytest.raises(ValueError):
-        assert switch.validate(STATE_OFF)
-
     with pytest.raises(ValueError):
         switch.validate(2)
 
@@ -264,6 +258,36 @@ def test_switch_repr(switch: Switch) -> None:
     )
 
 
+@patch("asyncio.Queue.put")
+async def test_number_request_with_unchanged_value(
+    mock_put, number: Number, bypass_asyncio_sleep, caplog
+) -> None:
+    """Test that a frame doesn't get dispatched if it's value is unchanged."""
+    assert not number.pending_update
+    assert not await number.set(5, retries=3)
+    assert number.pending_update
+    assert mock_put.await_count == 3  # type: ignore [unreachable]
+    mock_put.reset_mock()
+    assert "Timed out while trying to set 'test_number' parameter" in caplog.text
+    await number.set(5)
+    mock_put.assert_not_awaited()
+
+
+@patch("asyncio.Queue.put")
+async def test_switch_request_with_unchanged_value(
+    mock_put, switch: Switch, bypass_asyncio_sleep, caplog
+) -> None:
+    """Test that a frame doesn't get dispatched if it's value is unchanged."""
+    assert not switch.pending_update
+    assert not await switch.set(True, retries=3)
+    assert switch.pending_update
+    assert mock_put.await_count == 3  # type: ignore [unreachable]
+    mock_put.reset_mock()
+    assert "Timed out while trying to set 'test_switch' parameter" in caplog.text
+    await switch.set(True)
+    mock_put.assert_not_awaited()
+
+
 @patch("pyplumio.helpers.parameter.Switch.set")
 async def test_switch_turn_on(mock_set, switch: Switch) -> None:
     """Test that switch can be turned on."""