Merge pull request #1311 from ZLLentz/tst_failing_on_pip

TST: reproduce and fix pypi failures

docs/source/upcoming_release_notes/1311-tst_failing_on_pip.rst

@@ -0,0 +1,31 @@
+1311 tst_failing_on_pip
+#######################
+
+API Breaks
+----------
+- N/A
+
+Library Features
+----------------
+- N/A
+
+Device Features
+---------------
+- N/A
+
+New Devices
+-----------
+- N/A
+
+Bugfixes
+--------
+- N/A
+
+Maintenance
+-----------
+- Make test_at2l0_clear_errors pass more consistently on CI.
+- Add a utility for checking signal values that don't update promptly.
+
+Contributors
+------------
+- zllentz

pcdsdevices/tests/conftest.py

@@ -5,6 +5,7 @@
 import pkgutil
 import shutil
 import sys
+import time
 import warnings
 from pathlib import Path
 from types import ModuleType, SimpleNamespace
@@ -13,7 +14,7 @@
 import ophyd
 import pytest
 from epics import PV
-from ophyd.signal import LimitError
+from ophyd.signal import LimitError, Signal
 from ophyd.sim import FakeEpicsSignal, make_fake_device
 
 from .. import analog_signals, lens, lxe
@@ -259,3 +260,18 @@ def post(self, *args, **kwargs):
             self.posts.append((args, kwargs))
 
     return MockELog('TST')
+
+
+def wait_and_assert(sig: Signal, val: Any, tries: int = 10, wait: float = 0.1):
+    """
+    Wait for sig's value to be val, asserting it after waiting.
+
+    This should be used when the timing of the value changing is not
+    fully deterministic, such as when its governed by the execution of a
+    background thread.
+    """
+    for _ in range(tries):
+        if sig.get() == val:
+            break
+        time.sleep(wait)
+    assert sig.get() == val

pcdsdevices/tests/test_attenuator.py

@@ -9,6 +9,7 @@
 
 from ..attenuator import (AT1K2, AT1K4, AT2K2, AT2L0, MAX_FILTERS, AttBase,
                           Attenuator, _att_classes)
+from .conftest import wait_and_assert
 
 logger = logging.getLogger(__name__)
 
@@ -261,4 +262,4 @@ def test_at2l0_clear_errors(at2l0):
         assert not sig.get()
     at2l0.clear_errors()
     for sig in signals:
-        assert sig.get()
+        wait_and_assert(sig, 1)