fix(bec-processed-signal): fix read on processed signal, will force a read on linked signal now

ophyd_devices/utils/bec_processed_signal.py

@@ -147,6 +147,19 @@ class BECProcessedSignal(SignalRO):
                 compute_method=model_config["compute_method"], **model_config["devices"]
             )
 
+    def read(self) -> dict[str, Any]:
+        if self._metadata.get("connected", False) is False:
+            return super().read()
+        # Lazy import DSDevice to avoid circular import issues
+        # pylint: disable=import-outside-toplevel
+        from bec_server.device_server.devices.devicemanager import DSDevice
+
+        for inp in self.compute_model.method_inputs.values():
+            if not isinstance(inp, (Component, Device, Signal, DSDevice)):
+                continue  # Skip non-ophyd objects, they are additional arguments for the compute method
+            inp.read()  # Read the linked device/signals to ensure to be up to date before computing the value
+        return super().read()
+
     @staticmethod
     def get_device_object_from_bec(
         object_name: str, signal_name: str, device_manager: DeviceManagerDS

tests/test_processed_signal.py

@@ -2,6 +2,8 @@
 
 # pylint: disable=redefined-outer-name
 
+from unittest import mock
+
 import pytest
 from bec_server.device_server.tests.utils import DMMock
 from ophyd import Component as Cpt
@@ -121,6 +123,13 @@ def test_processed_signal_describe_metadata(processed_signal_from_device_manager
     assert "samy.readback" in info["method_inputs"]
 
 
+def test_processed_signal_forces_read(processed_signal_from_device_manager, samx):
+    """Test that get() forces read of all input signals."""
+    with mock.patch.object(samx.readback, "read") as mock_read:
+        processed_signal_from_device_manager.read()
+        mock_read.assert_called_once()
+
+
 def test_processed_signal_model_rejects_missing_required_inputs():
     """Test compute model validation when required kwargs are missing."""