test: add tests and refactor wecker.py state machine for testability

tests/test_wecker.py

@@ -0,0 +1,105 @@
+import pytest
+import sys
+from unittest.mock import MagicMock, patch
+
+# Mock RPi.GPIO and pygame before importing wecker
+sys.modules['RPi'] = MagicMock()
+sys.modules['RPi.GPIO'] = MagicMock()
+sys.modules['pygame'] = MagicMock()
+
+import wecker  # noqa: E402
+
+@pytest.fixture
+def mock_gpio():
+    with patch.object(wecker, 'GPIO') as mock:
+        mock.LOW = 0
+        mock.HIGH = 1
+        yield mock
+
+@pytest.fixture
+def mock_pygame():
+    with patch.object(wecker, 'pygame') as mock:
+        yield mock
+
+def test_set_led(mock_gpio):
+    wecker.set_led(True)
+    mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.LOW)
+    
+    wecker.set_led(False)
+    mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.HIGH)
+
+@patch('wecker.time.sleep')
+def test_blink_led(mock_sleep, mock_gpio):
+    wecker.blink_led(2)
+    # 2 blinks = 4 sleep calls, 2 set_led(True), 2 set_led(False)
+    assert mock_sleep.call_count == 4
+    # GPIO output called 4 times total (on, off, on, off)
+    assert mock_gpio.output.call_count == 4
+
+@patch('wecker.time.time')
+def test_run_alarm_start_to_wait(mock_time, mock_gpio, mock_pygame):
+    # Mock pygame.mixer.get_init() to return True so music plays
+    mock_pygame.mixer.get_init.return_value = True
+    
+    # Just run it in test mode, it should execute the loop once and exit
+    wecker.run_alarm(test_mode=True)
+    assert mock_pygame.mixer.music.play.called
+
+def test_state_machine_evaluation(mock_gpio, mock_pygame):
+    clock = wecker.AlarmClock()
+    
+    # Transition to ringing -> wait before blink
+    clock.update(100.0, True) # button press
+    assert clock.state == wecker.STATE_WAIT_BEFORE_BLINK
+    
+    # Wait 3 seconds -> blinking
+    with patch('wecker.blink_led'):
+        clock.update(103.1, False)
+    assert clock.state == wecker.STATE_BLINKING
+    
+    with patch('wecker.blink_led'):
+        clock.update(103.2, False)
+    assert clock.state == wecker.STATE_WAIT_FOR_INPUT
+    assert clock.target_blinks >= 1
+    
+    # Set the user presses to be correct
+    clock.target_blinks = 3
+    
+    # Press 1
+    clock.update(104.0, True)
+    clock.update(104.1, False)
+    # Press 2
+    clock.update(104.5, True)
+    clock.update(104.6, False)
+    # Press 3
+    clock.update(105.0, True)
+    clock.update(105.1, False)
+    
+    assert clock.user_presses == 3
+    
+    # Wait 3 seconds to evaluate
+    clock.update(108.2, False) # Triggers state change
+    keep_running = clock.update(108.3, False) # Triggers evaluation
+    
+    # It should evaluate, see it's correct, and return False (stop running)
+    assert clock.state == wecker.STATE_EVALUATING
+    assert not keep_running
+
+def test_state_machine_incorrect(mock_gpio, mock_pygame):
+    clock = wecker.AlarmClock()
+    clock.state = wecker.STATE_WAIT_FOR_INPUT
+    clock.target_blinks = 3
+    
+    # Only press once
+    clock.update(100.0, True)
+    clock.update(100.1, False)
+    
+    # Wait to evaluate
+    clock.last_interaction_time = 100.1
+    clock.update(103.2, False) # triggers eval state
+    keep_running = clock.update(103.3, False) # evals to incorrect
+    
+    # Evaluated incorrectly, should wait before retry
+    assert keep_running
+    assert clock.state == wecker.STATE_WAIT_BEFORE_RETRY
+