Update PI Device close method to catch VisaIOErrors (#141)

* fix: Remove outdated comment. * fix: Update close method to catch VisaIOErrors. * Apply suggestions from code review style: add more info to changelog, remove unnecessary whitespace. Co-authored-by: Nicholas Felt <[email protected]> Signed-off-by: Mike Wagoner <[email protected]> --------- Signed-off-by: Mike Wagoner <[email protected]> Co-authored-by: Nicholas Felt <[email protected]>
tektronix · Feb 8, 2024 · 2400d8e · 2400d8e
1 parent 0dabe4b
commit 2400d8e
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diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
@@ -34,7 +34,7 @@ repos:
       - id: remove-tabs
       - id: forbid-tabs
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.27.4
+    rev: 0.28.0
     hooks:
       - id: check-readthedocs
       - id: check-dependabot

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -33,6 +33,7 @@ Things to be included in the next release go here.
 ### Fixed
 
 - Fixed the code that detects VISA resource expressions to be able to detect SOCKET resource expressions properly.
+- Fixed PI device close method to catch VisaIOErrors and throw a warning, rather than an exception, when closing a PI device connection.
 
 ______________________________________________________________________
 

diff --git a/src/tm_devices/drivers/pi/pi_device.py b/src/tm_devices/drivers/pi/pi_device.py
@@ -4,6 +4,7 @@
 import os
 import socket
 import time
+import warnings
 
 from abc import ABC, abstractmethod
 from contextlib import contextmanager
@@ -13,6 +14,7 @@
 
 from packaging.version import Version
 from pyvisa import constants as visa_constants
+from pyvisa import VisaIOError
 
 from tm_devices.drivers.device import Device
 from tm_devices.drivers.pi._ieee488_2_commands import IEEE4882Commands
@@ -816,7 +818,12 @@ def _cleanup(self) -> None:
 
     def _close(self) -> None:
         """Close this device and all its used resources and components."""
-        self._visa_resource.close()
+        try:
+            self._visa_resource.close()
+        except VisaIOError as error:
+            warnings.warn(
+                f"Error encountered while closing the visa resource:\n{error}", stacklevel=2
+            )
         self._visa_resource = None  # pyright: ignore[reportAttributeAccessIssue]
         self._is_open = False
 

diff --git a/tests/test_pi_device.py b/tests/test_pi_device.py
@@ -113,3 +113,16 @@ def test_pi_device(  # noqa: PLR0915
     stdout = capsys.readouterr().out
     assert f"VISA timeout set to: {old_timeout}ms" in stdout
     assert scope.visa_timeout == old_timeout
+
+    # Test closing a device that is powered off
+    with mock.patch(
+        "pyvisa.resources.resource.Resource.close",
+        mock.MagicMock(side_effect=visa.VisaIOError(123)),
+    ), pytest.warns(Warning):
+        scope._close()  # noqa: SLF001
+        assert scope._visa_resource is None  # noqa: SLF001
+        assert not scope._is_open  # noqa: SLF001
+
+    # Re-open the device for device manager teardown
+    with mock.patch.dict("os.environ", {"TM_DEVICES_UNIT_TESTS_REBOOT_ALLOW": "true"}, clear=True):
+        assert scope._open()  # noqa: SLF001