chore: apply linting fixes and expand ruff coverage to test suite

tests/test_device_controller.py

@@ -1,10 +1,13 @@
-import pytest
 import logging
 from unittest.mock import MagicMock, patch
+
+import pytest
+
 from pygui.backend.controllers.device_controller import DeviceController
 from pygui.backend.data.local_settings import LocalSettings
 from pygui.serialcomm.serial_port import WaferInfo
 
+
 @pytest.fixture
 def mock_settings():
     s = LocalSettings()
@@ -16,8 +19,8 @@ def mock_settings():
 
 @pytest.fixture
 def controller(mock_settings):
-    import tempfile
     import shutil
+    import tempfile
     temp_dir = tempfile.mkdtemp()
     yield DeviceController(mock_settings, temp_dir)
     shutil.rmtree(temp_dir)
@@ -81,7 +84,7 @@ def test_clear_session(controller):
     controller._connection_status = "Connected"
     controller._selected_port = "COM1"
     controller._last_wafer_info = {"serialNumber": "P00001"}
-    
+
     controller.clearSession()
     assert controller.connectionStatus == "Disconnected"
     assert controller.selectedPort == ""
@@ -142,7 +145,7 @@ def test_parse_and_save_data_and_get_chart_data(controller):
 
     controller.parsedDataReady.connect(on_parsed)
     controller.parseAndSaveData("P", "COM1")
-    
+
     assert emitted_result is not None
     assert emitted_result.get("success") is True
     assert controller.dataRowCount == 1
@@ -159,16 +162,16 @@ def test_logging_handler(controller):
     assert any("Hello QML Activity Log" in line for line in controller._activity_log)
 
 def test_fresh_session_on_startup(mock_settings):
-    import tempfile
     import shutil
-    
+    import tempfile
+
     # Configure mock settings with some data to simulate previous session
     mock_settings.activity_log = ["[12:00:00] Old message"]
     mock_settings.selected_port = "COM9"
     mock_settings.last_wafer_info = {"familyCode": "P", "serialNumber": "P00002"}
     mock_settings.data_row_count = 50
     mock_settings.data_col_count = 244
-    
+
     temp_dir = tempfile.mkdtemp()
     try:
         new_controller = DeviceController(mock_settings, temp_dir)
@@ -187,19 +190,19 @@ def test_detect_wafer_clears_old_session(controller):
     controller._data_row_count = 10
     controller._data_col_count = 244
     controller._activity_log.append("[12:00:00] Previous message")
-    
+
     # We mock detect_all_ports to not run long or fail
     controller._service.detect_all_ports = MagicMock(return_value=(None, None))
-    
-    with patch("threading.Thread") as mock_thread:
+
+    with patch("threading.Thread"):
         controller.detectWafer()
-        
+
         # Verify it cleared all session variables and logs immediately at start of detect
         assert controller.selectedPort == ""
         assert controller.lastWaferInfo == ["", "", 0, "", 0, 0]
         assert controller.dataRowCount == 0
         assert controller.dataColCount == 0
-        
+
         # Log should only contain "Scanning all ports for wafer ..."
         assert len(controller._activity_log) == 1
         assert "Scanning all ports" in controller._activity_log[0]
@@ -227,6 +230,6 @@ def test_device_service_port_caching(controller):
 
         # Clear cache and scan again should invoke subprocess
         service.clear_port_scan_cache()
-        ports3 = service.enumerate_ports()
+        service.enumerate_ports()
         assert mock_run.call_count == 2