Fix import error on mac with system integrity protection (tektronix#109)

* fix: Update helper functions to account for System Integrity Protection on macOS which can cause errors when tm_devices is imported.

* ci: Update pre-commit versions.

* test: Update test to properly run tests from all three supported operating systems.

Signed-off-by: qthompso <[email protected]>

.pre-commit-config.yaml

@@ -34,7 +34,7 @@ repos:
       - id: remove-tabs
       - id: forbid-tabs
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.27.1
+    rev: 0.27.2
     hooks:
       - id: check-readthedocs
       - id: check-dependabot
@@ -50,7 +50,7 @@ repos:
     hooks:
       - id: blacken-docs
   - repo: https://github.com/lyz-code/yamlfix/
-    rev: 1.15.0
+    rev: 1.16.0
     hooks:
       - id: yamlfix
   - repo: https://github.com/executablebooks/mdformat
@@ -122,7 +122,7 @@ repos:
         always_run: true
         args: [., --min=10]
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.1.4
+    rev: v0.1.6
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]

CHANGELOG.md

@@ -26,6 +26,10 @@ Things to be included in the next release go here.
 
 - Updated the package classifiers for PyPI
 
+### Fixed
+
+- Fixed a crash observed on macOS when importing `tm_devices`, issue [#108](https://github.com/tektronix/tm_devices/issues/108)
+
 ______________________________________________________________________
 
 ## v1.0.0 (2023-11-13)

src/tm_devices/commands/_helpers/generic_commands.py

@@ -53,7 +53,7 @@ def __missing__(self, key: Any) -> Any:
             # noinspection PyArgumentList  # pylint: disable=not-callable
             dict.__setitem__(self, key, self.default_factory(key))  # type: ignore
             return cast(Any, self[key])
-        return cast(Any, super().__missing__(key))  # pyright: ignore [reportUnknownMemberType]
+        return cast(Any, super().__missing__(key))
 
 
 @total_ordering  # If comparisons are slowing down the code, implementing the rest would speed it up

src/tm_devices/components/dm_config_parser.py

@@ -339,7 +339,7 @@ def __parse_env_devices(self) -> List[Dict[str, Any]]:
         retval: List[Dict[str, Any]] = []
         msg: List[str] = []
         for dev_entry in devices_str_list:
-            temp_dict = {}
+            temp_dict: Dict[str, Any] = {}
             for dev_arg in dev_entry.split(","):
                 try:
                     dev_key, dev_val = dev_arg.split("=", 1)

src/tm_devices/drivers/pi/pi_device.py

@@ -30,7 +30,7 @@
 from tm_devices.helpers.constants_and_dataclasses import UNIT_TEST_TIMEOUT
 
 
-# pylint: disable=too-many-instance-attributes,too-many-public-methods
+# pylint: disable=too-many-public-methods
 class PIDevice(Device, ABC):
     """Base Programmable Interface (PI) device driver."""
 
@@ -64,7 +64,6 @@ def __init__(
         elif self._visa_library_path.endswith(".yaml"):  # pragma: no cover
             # Mark this as a simulated VISA backend
             self._visa_library_path += "@sim"
-        self._visa_backend = self._get_visa_backend()
         # Use a default timeout of 30 seconds, if running unit tests use a smaller amount.
         self._default_visa_timeout = (
             30000
@@ -159,11 +158,6 @@ def resource_expression(self) -> str:
         """Return the VISA resource expression."""
         return self._resource_expression
 
-    @property
-    def visa_backend(self) -> str:
-        """Return the VISA backend in use."""
-        return self._visa_backend
-
     @property
     def visa_timeout(self) -> float:
         """Return the current VISA timeout of the device in milliseconds."""
@@ -237,6 +231,11 @@ def series(self) -> str:
         """
         return get_model_series(self.model)
 
+    @cached_property
+    def visa_backend(self) -> str:
+        """Return the VISA backend in use."""
+        return get_visa_backend(self._visa_resource.visalib.library_path.path)
+
     ################################################################################################
     # Context Manager Methods
     ################################################################################################
@@ -819,14 +818,6 @@ def _close(self) -> None:
         self._visa_resource = None  # type: ignore
         self._is_open = False
 
-    def _get_visa_backend(self) -> str:
-        """Determine what the VISA backend is for this device.
-
-        Returns:
-            A string containing the VISA backend.
-        """
-        return get_visa_backend(self._visa_resource.visalib.library_path.path)
-
     def _has_errors(self) -> bool:
         """Check if the device has any errors.
 

src/tm_devices/drivers/pi/scopes/tekscope/tekscope.py

@@ -6,7 +6,7 @@
 from dataclasses import dataclass
 from functools import cached_property
 from types import MappingProxyType
-from typing import Any, cast, List, Literal, Optional, Tuple, Type, Union
+from typing import Any, cast, Dict, List, Literal, Optional, Tuple, Type, Union
 
 import pyvisa as visa
 
@@ -125,7 +125,7 @@ def __init__(
     def channel(self) -> "MappingProxyType[str, TekScopeChannel]":
         """Mapping of channel names to any detectable properties, attributes, and settings."""
         # TODO: overwrite in MSO2 driver, would remove need for try-except
-        channel_map = {}
+        channel_map: Dict[str, TekScopeChannel] = {}
 
         with self.temporary_verbose(False) and self.temporary_visa_timeout(
             500 if not bool(os.environ.get("TM_DEVICES_UNIT_TESTS_RUNNING")) else UNIT_TEST_TIMEOUT

src/tm_devices/helpers/functions.py

@@ -12,6 +12,7 @@
 import warnings
 
 from enum import EnumMeta
+from functools import lru_cache
 from typing import Any, Dict, Optional, Tuple, Type
 
 import requests
@@ -42,7 +43,6 @@
 ####################################################################################################
 # Private Constants
 ####################################################################################################
-_VISA_SYSTEM_DETAILS: Dict[str, Any] = pyvisa_util.get_system_details()
 _KEITHLEY_2_CHAR_MODEL_LOOKUP = {
     "24": "SMU",
     "26": "SMU",
@@ -436,7 +436,7 @@ def get_visa_backend(visa_lib_path: str) -> str:
     """
     visa_name = ""
 
-    system_visa_info = _VISA_SYSTEM_DETAILS
+    system_visa_info = _get_system_visa_info()
     # noinspection PyTypeChecker
     visa_backends: Dict[str, Any] = system_visa_info["backends"]
 
@@ -603,3 +603,25 @@ def _configure_visa_object(
                 setattr(serial_config, name, getattr(visa_object, name))
 
     return visa_object
+
+
+@lru_cache(maxsize=None)
+def _get_system_visa_info() -> Dict[str, Any]:
+    """Get the VISA information for the current system.
+
+    Returns:
+        A dictionary with the VISA info for the system.
+    """
+    fetch_backend_info = True
+
+    if platform.system().lower() == "darwin":
+        try:
+            output = subprocess.check_output(shlex.split("csrutil status")).decode(  # noqa: S603
+                "utf-8"
+            )
+        except subprocess.SubprocessError:
+            output = ""
+        if "System Integrity Protection status: enabled" in output:
+            fetch_backend_info = False
+
+    return pyvisa_util.get_system_details(backends=fetch_backend_info)

tests/test_helpers.py

@@ -5,9 +5,8 @@
 
 from collections import OrderedDict
 from contextlib import redirect_stdout
-from copy import deepcopy
 from io import StringIO
-from subprocess import CalledProcessError
+from subprocess import CalledProcessError, SubprocessError
 from typing import Any, Dict, Optional, Tuple
 from unittest import mock
 
@@ -309,9 +308,9 @@ def test_check_for_update(capsys: pytest.CaptureFixture[str]) -> None:
 
 def test_get_visa_backend() -> None:
     """Verify that the VISA backend can be determined properly."""
-    import tm_devices.helpers.functions  # pylint: disable=import-outside-toplevel
-
-    old_system_details = deepcopy(tm_devices.helpers.functions._VISA_SYSTEM_DETAILS)  # noqa: SLF001
+    from tm_devices.helpers.functions import (  # pylint: disable=import-outside-toplevel
+        _get_system_visa_info,
+    )
 
     testing_system_details: Dict[Any, Any] = {
         "pyvisa": "1.12.0",
@@ -363,18 +362,50 @@ def test_get_visa_backend() -> None:
         ),
     }
 
-    # Modify the constant for testing purposes
-    tm_devices.helpers.functions._VISA_SYSTEM_DETAILS = testing_system_details  # noqa: SLF001
-
     try:
-        assert get_visa_backend("tests/sim_devices/devices.yaml") == "PyVISA-sim"
-        assert get_visa_backend("py") == "PyVISA-py"
-        assert get_visa_backend("C:\\WINDOWS\\system32\\visa32.dll") == "NI-VISA"
-        assert get_visa_backend("C:\\WINDOWS\\system32\\visa.dll") == "Custom Vendor VISA"
-        assert get_visa_backend("nothing") == ""
+        _get_system_visa_info.cache_clear()
+        with mock.patch(
+            "pyvisa.util.get_system_details",
+            mock.MagicMock(return_value=testing_system_details),
+        ), mock.patch(
+            "platform.system",
+            mock.MagicMock(return_value="windows"),
+        ):
+            assert get_visa_backend("tests/sim_devices/devices.yaml") == "PyVISA-sim"
+            assert get_visa_backend("py") == "PyVISA-py"
+            assert get_visa_backend("C:\\WINDOWS\\system32\\visa32.dll") == "NI-VISA"
+            assert get_visa_backend("C:\\WINDOWS\\system32\\visa.dll") == "Custom Vendor VISA"
+            assert get_visa_backend("nothing") == ""
+
+        with mock.patch(
+            "platform.system",
+            mock.MagicMock(return_value="darwin"),
+        ):
+            _get_system_visa_info.cache_clear()
+            with mock.patch(
+                "subprocess.check_output",
+                mock.MagicMock(return_value=b"System Integrity Protection status: enabled."),
+            ):
+                assert get_visa_backend("tests/sim_devices/devices.yaml") == ""
+                assert get_visa_backend("py") == "PyVISA-py"
+
+            _get_system_visa_info.cache_clear()
+            with mock.patch(
+                "subprocess.check_output",
+                mock.MagicMock(return_value=b"System Integrity Protection status: disabled."),
+            ):
+                assert get_visa_backend("tests/sim_devices/devices.yaml") == "PyVISA-sim"
+                assert get_visa_backend("py") == "PyVISA-py"
+
+            _get_system_visa_info.cache_clear()
+            with mock.patch(
+                "subprocess.check_output",
+                mock.MagicMock(side_effect=SubprocessError()),
+            ):
+                assert get_visa_backend("tests/sim_devices/devices.yaml") == "PyVISA-sim"
+                assert get_visa_backend("py") == "PyVISA-py"
     finally:
-        # Reset the constant
-        tm_devices.helpers.functions._VISA_SYSTEM_DETAILS = old_system_details  # noqa: SLF001
+        _get_system_visa_info.cache_clear()
 
 
 @pytest.mark.parametrize(