Robust GUI test teardown; block QMessageBox

Improve camera dialog test fixture to show the dialog, yield it to tests, and perform a robust teardown: stop preview, reject/close the dialog, and wait for loader/scan worker threads and preview state to clear. Also add an autouse fixture that monkeypatches QMessageBox methods to raise on any unexpected modal dialog, preventing tests from hanging due to blocking message boxes. Small formatting/inline cleanup of MultiCameraSettings initialization included.

Author: C-Achard

tests/gui/camera_config/test_cam_dialog_e2e.py

@@ -47,19 +47,32 @@ def patch_factory(monkeypatch):
 
 @pytest.fixture
 def dialog(qtbot, patch_factory):
-    s = MultiCameraSettings(
-        cameras=[
-            CameraSettings(name="A", backend="opencv", index=0, enabled=True),
-        ]
-    )
+    s = MultiCameraSettings(cameras=[CameraSettings(name="A", backend="opencv", index=0, enabled=True)])
     d = CameraConfigDialog(None, s)
     qtbot.addWidget(d)
-    return d
+    d.show()
+    qtbot.waitExposed(d)
 
+    yield d
 
-# ---------------- End‑to‑End tests ----------------
+    # --- robust teardown ---
+    try:
+        d._stop_preview()
+    except Exception:
+        pass
 
+    try:
+        d.reject()  # calls _stop_preview + cancels scan worker
+    except Exception:
+        d.close()
 
+    # wait for threads to stop
+    qtbot.waitUntil(lambda: getattr(d, "_loader", None) is None, timeout=2000)
+    qtbot.waitUntil(lambda: getattr(d, "_scan_worker", None) is None, timeout=2000)
+    qtbot.waitUntil(lambda: not getattr(d, "_preview_active", False), timeout=2000)
+
+
+# ---------------- End‑to‑End tests ----------------
 def test_e2e_async_camera_scan(dialog, qtbot):
     qtbot.mouseClick(dialog.refresh_btn, Qt.LeftButton)
 

tests/gui/camera_config/test_cam_dialog_unit.py

@@ -1,24 +1,41 @@
 # tests/gui/camera_config/test_cam_dialog_unit.py
 from __future__ import annotations
 
+import numpy as np
 import pytest
 from PySide6.QtCore import Qt
 
+from dlclivegui.cameras import CameraFactory
+from dlclivegui.cameras.base import CameraBackend
 from dlclivegui.cameras.factory import DetectedCamera
 from dlclivegui.config import CameraSettings, MultiCameraSettings
 from dlclivegui.gui.camera_config_dialog import CameraConfigDialog
 
 
+class FakeBackend(CameraBackend):
+    def open(self):
+        pass
+
+    def close(self):
+        pass
+
+    def read(self):
+        return np.zeros((10, 10, 3), dtype=np.uint8), 0.0
+
+
 @pytest.fixture
 def dialog(qtbot, monkeypatch):
-    # Patch detect_cameras to avoid hardware access
     monkeypatch.setattr(
         "dlclivegui.cameras.CameraFactory.detect_cameras",
         lambda backend, max_devices=10, **kw: [
             DetectedCamera(index=0, label=f"{backend}-X"),
             DetectedCamera(index=1, label=f"{backend}-Y"),
         ],
     )
+    monkeypatch.setattr(CameraFactory, "create", lambda s: FakeBackend(s))
+
+    # Optional: prevent probe from running at all in pure unit tests
+    monkeypatch.setattr(CameraConfigDialog, "_start_probe_for_camera", lambda *a, **k: None)
 
     s = MultiCameraSettings(
         cameras=[
@@ -28,7 +45,15 @@ def dialog(qtbot, monkeypatch):
     )
     d = CameraConfigDialog(None, s)
     qtbot.addWidget(d)
-    return d
+    d.show()
+    qtbot.waitExposed(d)
+
+    yield d
+
+    try:
+        d.reject()
+    except Exception:
+        d.close()
 
 
 # ---------------------- UNIT TESTS ----------------------

tests/gui/conftest.py

@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import pytest
+from PySide6.QtWidgets import QMessageBox
 
 from dlclivegui.cameras.factory import CameraFactory
 from dlclivegui.config import CameraSettings
@@ -73,3 +74,22 @@ def _isolate_qsettings(tmp_path):
     s.sync()
 
     yield
+
+
+@pytest.fixture(autouse=True)
+def no_modal_messageboxes(monkeypatch):
+    """
+    Fail fast if a QMessageBox is shown unexpectedly.
+    This prevents teardown hangs caused by modal dialogs.
+    """
+
+    def _report(*args, **kwargs):
+        # args often: (parent, title, text, ...)
+        title = args[1] if len(args) > 1 else "<no-title>"
+        text = args[2] if len(args) > 2 else "<no-text>"
+        raise AssertionError(f"Unexpected QMessageBox: {title}\n{text}")
+
+    monkeypatch.setattr(QMessageBox, "warning", staticmethod(_report))
+    monkeypatch.setattr(QMessageBox, "critical", staticmethod(_report))
+    monkeypatch.setattr(QMessageBox, "information", staticmethod(_report))
+    monkeypatch.setattr(QMessageBox, "question", staticmethod(_report))