fix(omny/shutter): MonitorSignal wrapper with auto_monitor

csaxs_bec/devices/omny/shutter.py

@@ -13,6 +13,14 @@ from ophyd_devices import PSIDeviceBase
 logger = bec_logger.logger
 
 
+class MonitorSignal(Signal):
+    """A simple wrapper around ophyd Signal that automatically monitors the signal for changes."""
+
+    def __init__(self, *, name, auto_monitor=False, **kwargs):
+        super().__init__(name=name, **kwargs)
+        self.auto_monitor = auto_monitor
+
+
 class OMNYFastShutter(PSIDeviceBase, Device):
     """
     Fast Shutter control for OMNY setup. If started with at the beamline, it will expose
@@ -26,7 +34,7 @@ class OMNYFastShutter(PSIDeviceBase, Device):
     SUB_VALUE = "value"
     _default_sub = SUB_VALUE
 
-    shutter = Cpt(Signal, name="shutter")
+    shutter = Cpt(MonitorSignal, name="shutter", auto_monitor=True)
 
     # -----------------------------------------------------
     # User-facing shutter control functions

tests/tests_devices/test_omny_shutter.py

@@ -0,0 +1,69 @@
+import pytest
+from bec_server.device_server.tests.utils import DMMock
+
+from csaxs_bec.devices.omny.shutter import MonitorSignal, OMNYFastShutter
+
+
+@pytest.mark.parametrize("auto_monitor", [False, True])
+def test_monitor_signal_stores_auto_monitor(auto_monitor):
+    signal = MonitorSignal(name="signal", auto_monitor=auto_monitor)
+
+    assert signal.auto_monitor is auto_monitor
+
+
+def test_monitor_signal_put_propagates_value_to_readback_callback():
+    signal = MonitorSignal(name="signal", auto_monitor=True)
+    initial_value = signal.read()[signal.name]["value"]
+    callback_values = []
+    callback_reads = []
+
+    def _test_cb(value, old_value, **kwargs):
+        callback_values.append((value, old_value))
+        callback_reads.append(kwargs["obj"].read())
+
+    signal.subscribe(_test_cb, event_type=signal.SUB_VALUE, run=False)
+
+    signal.put(1)
+
+    assert callback_values == [(1, initial_value)]
+    assert len(callback_reads) == 1
+    assert callback_reads[0][signal.name]["value"] == 1
+    assert signal.read()[signal.name]["value"] == 1
+
+    signal.put(0)
+    assert callback_values == [(1, initial_value), (0, 1)]
+    assert len(callback_reads) == 2
+    assert callback_reads[1][signal.name]["value"] == 0
+    assert signal.read()[signal.name]["value"] == 0
+
+
+@pytest.fixture
+def omny_fast_shutter():
+    shutter = OMNYFastShutter(name="omny_fast_shutter", device_manager=DMMock())
+
+    try:
+        yield shutter
+    finally:
+        shutter.destroy()
+
+
+def test_omny_fast_shutter_uses_monitor_signal_with_auto_monitor(omny_fast_shutter):
+    assert isinstance(omny_fast_shutter.shutter, MonitorSignal)
+    assert omny_fast_shutter.shutter.auto_monitor is True
+
+
+def test_omny_fast_shutter_propagates_signal_changes_to_device_readback(omny_fast_shutter):
+    signal_name = omny_fast_shutter.shutter.name
+    callback_reads = []
+
+    def _test_cb(**kwargs):
+        callback_reads.append(omny_fast_shutter.read())
+
+    omny_fast_shutter.shutter.subscribe(_test_cb, event_type=omny_fast_shutter.shutter.SUB_VALUE, run=False)
+
+    omny_fast_shutter.shutter.put(1)
+
+    assert len(callback_reads) == 1
+    assert callback_reads[0][signal_name]["value"] == 1
+    assert omny_fast_shutter.read()[signal_name]["value"] == 1
+    assert omny_fast_shutter.fshstatus() == 1