tests, bluetooth: use a process instead of a thread

...for our fake daemon.

The in our fixture setup, the bluetooth daemon thread necessarily must
start before the manager, because the widget wants to connect on startup.
Of course, we fork() the manager (via multiprocessing), so spawning this
Thread before then will cause a warning. Let's just use a process instead.

This is in service of getting rid of all multithreading so that we can
enable -W error. It seems to (?) eliminate all the warnings besides those
in test_window_list.py, although 3.13 of course introduces more warnings
inside dependencies :(

Signed-off-by: Tycho Andersen <[email protected]>

test/widgets/test_bluetooth.py

@@ -18,13 +18,13 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 import asyncio
+import multiprocessing
 import os
 import shutil
 import signal
 import subprocess
 import time
 from enum import Enum
-from threading import Thread
 
 import pytest
 from dbus_next._private.address import get_session_bus_address
@@ -134,11 +134,8 @@ def Percentage(self) -> "d":  # noqa: F821, N802
         return 75
 
 
-class Bluez(Thread):
-    """Class that runs fake UPower interface in a thread."""
-
-    def __init__(self, *args, **kwargs):
-        Thread.__init__(self, *args, **kwargs)
+class Bluez:
+    """Class that runs fake UPower interface."""
 
     async def start_server(self):
         """Connects to the bus and publishes 3 interfaces."""
@@ -190,7 +187,7 @@ def run(self):
 
 
 @pytest.fixture()
-def dbus_thread(monkeypatch):
+def fake_dbus_daemon(monkeypatch):
     """Start a thread which publishes a fake bluez interface on dbus."""
     # for Github CI/Ubuntu, dbus-launch is provided by "dbus-x11" package
     launcher = shutil.which("dbus-launch")
@@ -222,9 +219,8 @@ def dbus_thread(monkeypatch):
             except ValueError:
                 pass
 
-    t = Bluez()
-    t.daemon = True
-    t.start()
+    p = multiprocessing.Process(target=Bluez().run)
+    p.start()
 
     # Pause for the dbus interface to come up
     time.sleep(1)
@@ -234,6 +230,7 @@ def dbus_thread(monkeypatch):
     # Stop the bus
     if pid:
         os.kill(pid, signal.SIGTERM)
+        p.kill()
 
 
 @pytest.fixture
@@ -251,7 +248,7 @@ def force_session_bus(bus_type):
 
 
 @pytest.fixture
-def bluetooth_manager(request, widget, dbus_thread, manager_nospawn):
+def bluetooth_manager(request, widget, fake_dbus_daemon, manager_nospawn):
     class BluetoothConfig(BareConfig):
         screens = [Screen(top=Bar([widget(**getattr(request, "param", dict()))], 20))]