Web frontend

python-backend/tests/test_startup.py

@@ -0,0 +1,128 @@
+"""What the app does when the config leaves the hardware out.
+
+Both of these are deliberately warnings rather than errors: a spare machine running
+only the web front-end is a supported way to use this, and it should say so once at
+startup rather than fail or - worse - look like it is working when it is not.
+"""
+
+from __future__ import annotations
+
+import copy
+import logging
+from pathlib import Path
+from typing import Any
+
+import pytest
+
+from musicmouse.__main__ import _build_player, wants_hardware
+from musicmouse.bus import EventBus
+from musicmouse.clock import RealClock
+from musicmouse.config import SIMULATE, Config, ConfigError, load_config
+from musicmouse.devices.null_transport import NullTransport
+from musicmouse.simulator.fake_player import FakePlayer
+from tests.conftest import VALID_CONFIG, write_config
+
+
+def _config(config_dir: Path, *, drop: tuple[str, ...] = (), **general: Any) -> Config:
+    data = copy.deepcopy(VALID_CONFIG)
+    data["general"].update(general)
+    for key in drop:
+        data["general"].pop(key, None)
+    return load_config(write_config(config_dir, data))
+
+
+# ------------------------------------------------------------------- serial port
+
+
+def test_a_missing_serial_port_is_an_error(config_dir: Path) -> None:
+    """Simulation has to be asked for. A config that lost the line must not boot."""
+    with pytest.raises(ConfigError) as excinfo:
+        _config(config_dir, drop=("serial_port",))
+    assert "general.serial_port" in str(excinfo.value)
+    assert "required" in str(excinfo.value)
+
+
+def test_a_missing_alsa_device_is_an_error(config_dir: Path) -> None:
+    with pytest.raises(ConfigError) as excinfo:
+        _config(config_dir, drop=("alsa_device",))
+    assert "general.alsa_device" in str(excinfo.value)
+    assert "required" in str(excinfo.value)
+
+
+def test_both_missing_are_reported_together(config_dir: Path) -> None:
+    with pytest.raises(ConfigError) as excinfo:
+        _config(config_dir, drop=("serial_port", "alsa_device"))
+    message = str(excinfo.value)
+    assert "2 problems" in message
+    assert "general.serial_port" in message
+    assert "general.alsa_device" in message
+
+
+def test_simulate_switches_off_the_serial_link(
+    config_dir: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    config = _config(config_dir, serial_port=SIMULATE)
+    assert config.general.serial_simulated is True
+
+    with caplog.at_level(logging.WARNING):
+        assert wants_hardware(config, False) is False
+    assert "running without the mouse" in caplog.text
+
+
+def test_a_real_port_is_used(config_dir: Path) -> None:
+    config = _config(config_dir)
+    assert config.general.serial_simulated is False
+    assert wants_hardware(config, False) is True
+
+
+def test_the_flag_wins_over_a_configured_port(config_dir: Path) -> None:
+    assert wants_hardware(_config(config_dir), True) is False
+
+
+# ------------------------------------------------------------------ audio device
+
+
+async def test_simulate_gives_a_silent_player(
+    config_dir: Path, caplog: pytest.LogCaptureFixture
+) -> None:
+    bus = EventBus()
+    await bus.start()
+    try:
+        general = _config(config_dir, alsa_device=SIMULATE).general
+        assert general.audio_simulated is True
+
+        with caplog.at_level(logging.WARNING):
+            player = _build_player(bus, general, clock=RealClock())
+
+        assert isinstance(player, FakePlayer)
+        assert "alsa_device" in caplog.text
+        assert "nothing will be audible" in caplog.text
+        # The clamps still come from the config, so volume behaves the same either way.
+        assert player.volume == 40
+        player.set_volume(999)
+        assert player.volume == 60
+    finally:
+        player.close()
+        await bus.stop()
+
+
+async def test_an_alsa_device_asks_for_the_real_player(config_dir: Path) -> None:
+    """Only that it tries: instantiating VlcPlayer needs libVLC, which CI has not got."""
+    bus = EventBus()
+    await bus.start()
+    try:
+        general = _config(config_dir, alsa_device="default").general
+        assert general.audio_simulated is False
+        with pytest.raises(Exception):  # noqa: B017 - ImportError or an OSError from libVLC
+            _build_player(bus, general, clock=RealClock())
+    finally:
+        await bus.stop()
+
+
+# ---------------------------------------------------------------- null transport
+
+
+def test_the_null_transport_drops_what_it_is_handed() -> None:
+    transport = NullTransport()
+    transport.write(b"\x00\x01\x02")
+    assert transport.connected is False