fix(io): keep plyer backend probe warnings out of alerts

Without dbus or notify-send, plyer warned twice before raising NotImplementedError, which AlertsService already reports with its print fallback.

Author: fmind

src/bikes/io/services.py

@@ -9,6 +9,7 @@
 import sys
 import typing as T
 import urllib.parse
+import warnings
 
 import loguru
 import mlflow
@@ -146,12 +147,16 @@ def notify(self, title: str, message: str) -> None:
                 notify_message = self._truncate(message, self._MAX_MESSAGE_LENGTH)
                 app_name = self._truncate(app_name, self._MAX_APP_NAME_LENGTH)
             try:
-                notification.notify(
-                    title=notify_title,
-                    message=notify_message,
-                    app_name=app_name,
-                    timeout=self.timeout,
-                )
+                # plyer warns while it probes for a backend (dbus, notify-send): the
+                # NotImplementedError fallback below already reports a missing one.
+                with warnings.catch_warnings():
+                    warnings.filterwarnings(action="ignore", category=UserWarning, module="plyer")
+                    notification.notify(
+                        title=notify_title,
+                        message=notify_message,
+                        app_name=app_name,
+                        timeout=self.timeout,
+                    )
             except NotImplementedError:
                 print("Notifications are not supported on this system.")  # noqa: T201  # user-facing fallback
                 self._print(title=title, message=message)

tests/io/test_services.py

@@ -1,5 +1,7 @@
 # %% IMPORTS
 
+import warnings
+
 import _pytest.capture as pc
 import _pytest.logging as pl
 import mlflow
@@ -41,6 +43,25 @@ def test_alerts_service(enable: bool, mocker: pm.MockerFixture, capsys: pc.Captu
         assert capsys.readouterr().out == "[Bikes] test: hello\n", "Notification should be printed to stdout!"
 
 
+def test_alerts_service__silences_backend_probe_warnings(
+    mocker: pm.MockerFixture, capsys: pc.CaptureFixture[str]
+) -> None:
+    # given
+    def notify(**_kwargs: str) -> None:
+        warnings.warn_explicit("notify-send not found.", UserWarning, "notification.py", 1, module="plyer.linux")
+        raise NotImplementedError
+
+    service = services.AlertsService(enable=True)
+    mocker.patch.object(services, "notification", new=mocker.Mock()).notify.side_effect = notify
+    # when
+    with warnings.catch_warnings(record=True) as caught:
+        warnings.simplefilter("always")
+        service.notify(title="test", message="hello")
+    # then
+    assert caught == [], "Backend probe warnings should not reach the user!"
+    assert "Notifications are not supported on this system." in capsys.readouterr().out
+
+
 def test_alerts_service__not_supported(mocker: pm.MockerFixture, capsys: pc.CaptureFixture[str]) -> None:
     # given
     service = services.AlertsService(enable=True)