test___signal_with_line_names___change_line_names_property___signal_returns_new_line_name and _DigitalWaveformExtendedProperties

Author: Mike Prosser

src/nitypes/waveform/_digital/_waveform.py

@@ -86,6 +86,30 @@ def success(self) -> bool:
     """A collection of test failure information."""
 
 
+class _DigitalWaveformExtendedProperties(ExtendedPropertyDictionary):
+    """Extended properties that invalidate cached line names when NI_LineNames is modified."""
+
+    __slots__ = ["_waveform"]
+
+    def __init__(
+        self,
+        waveform: DigitalWaveform[Any],
+        properties: Mapping[str, ExtendedPropertyValue] | None = None,
+    ) -> None:
+        super().__init__(properties)
+        self._waveform = waveform
+
+    def __setitem__(self, key: str, value: ExtendedPropertyValue, /) -> None:
+        super().__setitem__(key, value)
+        if key == LINE_NAMES:
+            self._waveform._line_names = None
+
+    def __delitem__(self, key: str, /) -> None:
+        super().__delitem__(key)
+        if key == LINE_NAMES:
+            self._waveform._line_names = None
+
+
 class DigitalWaveform(Generic[TDigitalState]):
     """A digital waveform, which encapsulates digital data and timing information.
 
@@ -805,9 +829,9 @@ def __init__(
             raise invalid_arg_type("raw data", "NumPy ndarray", data)
 
         if copy_extended_properties or not isinstance(
-            extended_properties, ExtendedPropertyDictionary
+            extended_properties, _DigitalWaveformExtendedProperties
         ):
-            extended_properties = ExtendedPropertyDictionary(extended_properties)
+            extended_properties = _DigitalWaveformExtendedProperties(self, extended_properties)
         self._extended_properties = extended_properties
 
         if timing is None:
@@ -1334,12 +1358,24 @@ def __eq__(self, value: object, /) -> bool:
             and self._timing == value._timing
         )
 
+    def __copy__(self) -> Self:
+        """Return a shallow copy of self."""
+        return self.__class__(
+            self._sample_count,
+            self.signal_count,
+            self.dtype,
+            data=self.data,
+            extended_properties=self._extended_properties,
+            copy_extended_properties=False,
+            timing=self._timing,
+        )
+
     def __reduce__(self) -> tuple[Any, ...]:
         """Return object state for pickling."""
         ctor_args = (self._sample_count, self.signal_count, self.dtype)
         ctor_kwargs: dict[str, Any] = {
             "data": self.data,
-            "extended_properties": self._extended_properties,
+            "extended_properties": ExtendedPropertyDictionary(self._extended_properties),
             "copy_extended_properties": False,
             "timing": self._timing,
         }

tests/unit/waveform/test_digital_waveform_signal.py

@@ -138,6 +138,21 @@ def test___signal_with_line_names___set_signal_name___returns_line_name() -> Non
     assert waveform.extended_properties["NI_LineNames"] == "port0/line2, MySignal, port0/line0"
 
 
+def test___signal_with_line_names___change_line_names_property___signal_returns_new_line_name() -> (
+    None
+):
+    waveform = DigitalWaveform(
+        10, 2, extended_properties={"NI_LineNames": "port0/line1, port0/line0"}
+    )
+    assert waveform.signals[0].name == "port0/line0"
+    assert waveform.signals[1].name == "port0/line1"
+
+    waveform.extended_properties["NI_LineNames"] = "port0/line11, port0/line10"
+
+    assert waveform.signals[0].name == "port0/line10"
+    assert waveform.signals[1].name == "port0/line11"
+
+
 ###############################################################################
 # signal data
 ###############################################################################