only subscribe with event_type="setpoint" when it is available

CHANGES.rst

@@ -26,6 +26,12 @@ describe future plans.
 
    Release expected by 2024-12-31.
 
+   Fixes
+   -----
+
+   - PVPositionerSoftDone used an invalid subscription event type
+     in unusual cases (with fake ophyd simulated devices).
+
 1.7.1
 ******
 

apstools/devices/positioner_soft_done.py

@@ -138,7 +138,10 @@ def __init__(
 
         self.readback.subscribe(self.cb_readback)
         self.setpoint.subscribe(self.cb_setpoint)
-        self.setpoint.subscribe(self.cb_update_target, event_type="setpoint")
+        options = {}
+        if "setpoint" in self.event_types:
+            options["event_type"] = "setpoint"
+        self.setpoint.subscribe(self.cb_update_target, **options)
 
         # cancel subscriptions before object is garbage collected
         weakref.finalize(self.readback, self.readback.unsubscribe_all)

apstools/devices/tests/test_positioner_soft_done.py

@@ -1,19 +1,21 @@
 import math
 import time
+from contextlib import nullcontext as does_not_raise
 
 import pytest
 from ophyd import Component
 from ophyd import EpicsSignal
+from ophyd.sim import instantiate_fake_device
 
 from ...synApps.swait import UserCalcsDevice
 from ...tests import IOC_GP
 from ...tests import common_attribute_quantities_test
 from ...tests import rand
 from ...tests import timed_pause
 from ...utils import run_in_thread
+from ..positioner_soft_done import TARGET_UNDEFINED
 from ..positioner_soft_done import PVPositionerSoftDone
 from ..positioner_soft_done import PVPositionerSoftDoneWithStop
-from ..positioner_soft_done import TARGET_UNDEFINED
 
 PV_PREFIX = f"{IOC_GP}gp:"
 delay_active = False
@@ -365,3 +367,19 @@ def motion(p, goal):
     motion(calcpos, round(rand(-1.1, 0.2), 4))  # known starting position
     motion(calcpos, target)
     motion(calcpos, target)  # issue #725, repeated move to same target
+
+
+def test_issue_1022():
+    """
+    PVPositionerSoftDone should work with simulated fake devices.
+
+    'instantiate_fake_device()' produces a device that does not
+    have the 'setpoint' event_type.
+    """
+    with does_not_raise():
+        d = instantiate_fake_device(
+            PVPositionerSoftDone,
+            readback_pv="spam:",
+            setpoint_pv="eggs:",
+        )
+    assert d is not None