Add crash guard, logging, and defensive error handling to prevent lockout

Global sys.excepthook unlocks the session on unhandled exceptions.
Structured logging to stderr and optional file at /var/cache/moonlock/.
Window creation, CSS loading, and fingerprint start wrapped in
try/except with automatic session unlock when all windows fail.
This commit is contained in:
2026-03-26 17:56:45 +01:00
parent 7cee4f4f8d
commit 3f31387305
7 changed files with 428 additions and 24 deletions
+79
View File
@@ -150,3 +150,82 @@ class TestFingerprintSignalHandling:
on_failure.assert_not_called()
# Should NOT restart — verification still in progress
listener._device_proxy.VerifyStart.assert_not_called()
class TestFingerprintStartErrorHandling:
"""Tests for GLib.Error handling in start()."""
def test_claim_glib_error_logs_and_returns_without_starting(self):
"""When Claim() raises GLib.Error, start() should not proceed."""
from gi.repository import GLib
listener = FingerprintListener.__new__(FingerprintListener)
listener._device_proxy = MagicMock()
listener._device_path = "/dev/0"
listener._signal_id = None
listener._running = False
listener._on_success = None
listener._on_failure = None
listener._device_proxy.Claim.side_effect = GLib.Error(
"net.reactivated.Fprint.Error.AlreadyClaimed"
)
on_success = MagicMock()
on_failure = MagicMock()
listener.start("testuser", on_success=on_success, on_failure=on_failure)
# Should NOT have connected signals or started verification
listener._device_proxy.connect.assert_not_called()
listener._device_proxy.VerifyStart.assert_not_called()
assert listener._running is False
def test_verify_start_glib_error_disconnects_and_releases(self):
"""When VerifyStart() raises GLib.Error, start() should clean up."""
from gi.repository import GLib
listener = FingerprintListener.__new__(FingerprintListener)
listener._device_proxy = MagicMock()
listener._device_path = "/dev/0"
listener._signal_id = None
listener._running = False
listener._on_success = None
listener._on_failure = None
# Claim succeeds, signal connect returns an ID, VerifyStart fails
listener._device_proxy.connect.return_value = 99
listener._device_proxy.VerifyStart.side_effect = GLib.Error(
"net.reactivated.Fprint.Error.Internal"
)
on_success = MagicMock()
on_failure = MagicMock()
listener.start("testuser", on_success=on_success, on_failure=on_failure)
# Should have disconnected the signal
listener._device_proxy.disconnect.assert_called_once_with(99)
# Should have released the device
listener._device_proxy.Release.assert_called_once()
assert listener._running is False
assert listener._signal_id is None
def test_start_sets_running_true_only_on_success(self):
"""_running should only be True after both Claim and VerifyStart succeed."""
listener = FingerprintListener.__new__(FingerprintListener)
listener._device_proxy = MagicMock()
listener._device_path = "/dev/0"
listener._signal_id = None
listener._running = False
listener._on_success = None
listener._on_failure = None
listener._device_proxy.connect.return_value = 42
on_success = MagicMock()
on_failure = MagicMock()
listener.start("testuser", on_success=on_success, on_failure=on_failure)
assert listener._running is True
+242
View File
@@ -0,0 +1,242 @@
# ABOUTME: Tests for the Moonlock application entry point.
# ABOUTME: Covers logging setup, defensive window creation, and CSS error handling.
import logging
import sys
from pathlib import Path
from unittest.mock import patch, MagicMock
import pytest
@pytest.fixture(autouse=True)
def _mock_gtk(monkeypatch):
"""Prevent GTK from requiring a display during test collection."""
mock_gi = MagicMock()
mock_gtk = MagicMock()
mock_gdk = MagicMock()
mock_session_lock = MagicMock()
# Pre-populate gi.repository with our mocks
modules = {
"gi": mock_gi,
"gi.repository": MagicMock(Gtk=mock_gtk, Gdk=mock_gdk, Gtk4SessionLock=mock_session_lock),
}
with monkeypatch.context() as m:
# Only patch missing/problematic modules if not already loaded
for mod_name, mod in modules.items():
if mod_name not in sys.modules:
m.setitem(sys.modules, mod_name, mod)
yield
def _import_main():
"""Import main module lazily after GTK mocking is in place."""
from moonlock.main import MoonlockApp, _setup_logging
return MoonlockApp, _setup_logging
class TestSetupLogging:
"""Tests for the logging infrastructure."""
def test_setup_logging_adds_stderr_handler(self):
"""_setup_logging() should add a StreamHandler to the root logger."""
_, _setup_logging = _import_main()
root = logging.getLogger()
handlers_before = len(root.handlers)
_setup_logging()
assert len(root.handlers) > handlers_before
# Clean up handlers we added
for handler in root.handlers[handlers_before:]:
root.removeHandler(handler)
def test_setup_logging_sets_info_level(self):
"""_setup_logging() should set root logger to INFO level."""
_, _setup_logging = _import_main()
root = logging.getLogger()
original_level = root.level
_setup_logging()
assert root.level == logging.INFO
# Restore
root.setLevel(original_level)
for handler in root.handlers[:]:
root.removeHandler(handler)
@patch("moonlock.main._LOG_DIR")
@patch("logging.FileHandler")
def test_setup_logging_adds_file_handler_when_dir_exists(self, mock_fh, mock_log_dir):
"""_setup_logging() should add a FileHandler when log directory exists."""
_, _setup_logging = _import_main()
mock_log_dir.is_dir.return_value = True
root = logging.getLogger()
handlers_before = len(root.handlers)
_setup_logging()
mock_fh.assert_called_once()
# Clean up
for handler in root.handlers[handlers_before:]:
root.removeHandler(handler)
@patch("moonlock.main._LOG_DIR")
def test_setup_logging_skips_file_handler_when_dir_missing(self, mock_log_dir):
"""_setup_logging() should not fail when log directory doesn't exist."""
_, _setup_logging = _import_main()
mock_log_dir.is_dir.return_value = False
root = logging.getLogger()
handlers_before = len(root.handlers)
_setup_logging()
assert len(root.handlers) >= handlers_before
# Clean up
for handler in root.handlers[handlers_before:]:
root.removeHandler(handler)
class TestCssErrorHandling:
"""Tests for CSS loading error handling."""
@patch("moonlock.main.Gdk.Display.get_default")
@patch("moonlock.main.Gtk.CssProvider")
@patch("moonlock.main.files")
def test_load_css_logs_error_on_exception(self, mock_files, mock_css_cls, mock_display):
"""CSS loading errors should be logged, not raised."""
MoonlockApp, _ = _import_main()
mock_files.return_value.__truediv__ = MagicMock(return_value=Path("/nonexistent"))
mock_css = MagicMock()
mock_css.load_from_path.side_effect = Exception("CSS parse error")
mock_css_cls.return_value = mock_css
app = MoonlockApp.__new__(MoonlockApp)
app._config = MagicMock()
# Should not raise
with patch("moonlock.main.logger") as mock_logger:
app._load_css()
mock_logger.exception.assert_called_once()
class TestDefensiveWindowCreation:
"""Tests for defensive window creation in session lock mode."""
@patch("moonlock.main.LockscreenWindow")
@patch("moonlock.main.FingerprintListener")
@patch("moonlock.main.Gdk.Display.get_default")
@patch("moonlock.main.Gtk4SessionLock")
def test_single_window_failure_does_not_stop_other_windows(
self, mock_session_lock, mock_display, mock_fp, mock_window_cls
):
"""If one window fails, others should still be created."""
MoonlockApp, _ = _import_main()
app = MoonlockApp.__new__(MoonlockApp)
app._config = MagicMock()
app._windows = []
# Two monitors
monitor1 = MagicMock()
monitor2 = MagicMock()
monitors = MagicMock()
monitors.get_n_items.return_value = 2
monitors.get_item.side_effect = [monitor1, monitor2]
mock_display.return_value.get_monitors.return_value = monitors
lock_instance = MagicMock()
mock_session_lock.Instance.new.return_value = lock_instance
app._lock_instance = lock_instance
# First window creation fails, second succeeds
window_ok = MagicMock()
mock_window_cls.side_effect = [Exception("GTK error"), window_ok]
with patch("moonlock.main.logger"):
app._activate_with_session_lock()
# One window should have been created despite the first failure
assert len(app._windows) == 1
@patch("moonlock.main.LockscreenWindow")
@patch("moonlock.main.FingerprintListener")
@patch("moonlock.main.Gdk.Display.get_default")
@patch("moonlock.main.Gtk4SessionLock")
def test_all_windows_fail_unlocks_session(
self, mock_session_lock, mock_display, mock_fp, mock_window_cls
):
"""If ALL windows fail to create, session should be unlocked to prevent lockout."""
MoonlockApp, _ = _import_main()
app = MoonlockApp.__new__(MoonlockApp)
app._config = MagicMock()
app._windows = []
# One monitor
monitors = MagicMock()
monitors.get_n_items.return_value = 1
monitors.get_item.return_value = MagicMock()
mock_display.return_value.get_monitors.return_value = monitors
lock_instance = MagicMock()
mock_session_lock.Instance.new.return_value = lock_instance
app._lock_instance = lock_instance
# Window creation fails
mock_window_cls.side_effect = Exception("GTK error")
with patch("moonlock.main.logger"):
app._activate_with_session_lock()
# Session should have been unlocked to prevent permanent lockout
lock_instance.unlock.assert_called_once()
class TestCrashGuard:
"""Tests for the global exception handler that prevents lockout on crash."""
def test_crash_guard_unlocks_session_on_unhandled_exception(self):
"""sys.excepthook should unlock the session when an exception reaches it."""
MoonlockApp, _ = _import_main()
from moonlock.main import _install_crash_guard
app = MoonlockApp.__new__(MoonlockApp)
app._lock_instance = MagicMock()
original_hook = sys.excepthook
_install_crash_guard(app)
try:
# Simulate an unhandled exception reaching the hook
with patch("moonlock.main.logger"):
sys.excepthook(RuntimeError, RuntimeError("segfault"), None)
app._lock_instance.unlock.assert_called_once()
finally:
sys.excepthook = original_hook
def test_crash_guard_survives_unlock_failure(self):
"""Crash guard should not raise even if unlock() itself fails."""
MoonlockApp, _ = _import_main()
from moonlock.main import _install_crash_guard
app = MoonlockApp.__new__(MoonlockApp)
app._lock_instance = MagicMock()
app._lock_instance.unlock.side_effect = Exception("protocol error")
original_hook = sys.excepthook
_install_crash_guard(app)
try:
with patch("moonlock.main.logger"):
# Should not raise despite unlock failure
sys.excepthook(RuntimeError, RuntimeError("crash"), None)
finally:
sys.excepthook = original_hook