test: added tests for dynamic_pseudo

ophyd_devices/utils/dynamic_pseudo.py

@@ -3,6 +3,7 @@ This module provides a class for creating a pseudo signal that is computed from
 """
 
 from functools import reduce
+from typing import Callable
 
 from ophyd import SignalRO
 from ophyd.ophydobj import Kind
@@ -63,7 +64,7 @@ class ComputedSignal(SignalRO):
         self._run_subs(sub_type=self.SUB_VALUE, old_value=None, value=self.get())
 
     @property
-    def compute_method(self):
+    def compute_method(self) -> Callable | None:
         """
         Set the compute method for the pseudo signal
 
@@ -117,6 +118,7 @@ class ComputedSignal(SignalRO):
         self._input_signals = signals
 
     def get(self):
-        if self._compute_method:
-            return self._compute_method(*self._input_signals)
+        if self.compute_method:
+            # pylint: disable=not-callable
+            return self.compute_method(*self.input_signals)
         return None

tests/test_dynamic_pseudo.py

@@ -0,0 +1,30 @@
+from unittest import mock
+
+import pytest
+
+from ophyd_devices.utils.dynamic_pseudo import ComputedSignal
+from tests.utils import DMMock
+
+
+@pytest.fixture
+def device_manager_with_devices():
+    dm = DMMock()
+    dm.add_device("a")
+    dm.add_device("b")
+    device_mock = mock.MagicMock()
+    device_mock.obj.readback.get.return_value = 20
+    dm.devices["a"] = device_mock
+    dm.devices["b"] = device_mock
+
+    return dm
+
+
+def test_computed_signal(device_manager_with_devices):
+    signal = ComputedSignal(name="test", device_manager=device_manager_with_devices)
+    assert signal.get() is None
+
+    signal.compute_method = "def test(a, b): return a.get() + b.get()"
+    signal.input_signals = ["a_readback", "b_readback"]
+    assert signal.get() == 40
+
+    assert callable(signal.compute_method)