Merge branch 'main' into feat/code-scroll

tests/fixtures/__init__.py

@@ -0,0 +1,236 @@
+"""
+Pytest fixtures for mocking external dependencies (network, filesystem).
+"""
+
+import json
+from unittest.mock import MagicMock
+
+import pytest
+
+
+@pytest.fixture
+def mock_feed_response():
+    """Mock RSS feed response data."""
+    return b"""<?xml version="1.0" encoding="UTF-8" ?>
+<rss version="2.0">
+  <channel>
+    <title>Test Feed</title>
+    <link>https://example.com</link>
+    <item>
+      <title>Test Headline One</title>
+      <pubDate>Sat, 15 Mar 2025 12:00:00 GMT</pubDate>
+    </item>
+    <item>
+      <title>Test Headline Two</title>
+      <pubDate>Sat, 15 Mar 2025 11:00:00 GMT</pubDate>
+    </item>
+    <item>
+      <title>Sports: Team Wins Championship</title>
+      <pubDate>Sat, 15 Mar 2025 10:00:00 GMT</pubDate>
+    </item>
+  </channel>
+</rss>"""
+
+
+@pytest.fixture
+def mock_gutenberg_response():
+    """Mock Project Gutenberg text response."""
+    return """Project Gutenberg's Collection, by Various
+
+*** START OF SOME TEXT ***
+This is a test poem with multiple lines
+that should be parsed as stanzas.
+
+Another stanza here with different content
+and more lines to test the parsing logic.
+
+Yet another stanza for variety
+in the test data.
+
+*** END OF SOME TEXT ***"""
+
+
+@pytest.fixture
+def mock_gutenberg_empty():
+    """Mock Gutenberg response with no valid stanzas."""
+    return """Project Gutenberg's Collection
+
+*** START OF TEXT ***
+THIS IS ALL CAPS AND SHOULD BE SKIPPED
+
+I.
+
+*** END OF TEXT ***"""
+
+
+@pytest.fixture
+def mock_ntfy_message():
+    """Mock ntfy.sh SSE message."""
+    return json.dumps(
+        {
+            "id": "test123",
+            "event": "message",
+            "title": "Test Title",
+            "message": "Test message body",
+            "time": 1234567890,
+        }
+    ).encode()
+
+
+@pytest.fixture
+def mock_ntfy_keepalive():
+    """Mock ntfy.sh keepalive message."""
+    return b'data: {"event":"keepalive"}\n\n'
+
+
+@pytest.fixture
+def mock_google_translate_response():
+    """Mock Google Translate API response."""
+    return json.dumps(
+        [
+            [["Translated text", "Original text", None, 0.8], None, "en"],
+            None,
+            None,
+            [],
+            [],
+            [],
+            [],
+        ]
+    )
+
+
+@pytest.fixture
+def mock_feedparser():
+    """Create a mock feedparser.parse function."""
+
+    def _mock(data):
+        mock_result = MagicMock()
+        mock_result.bozo = False
+        mock_result.entries = [
+            {
+                "title": "Test Headline",
+                "published_parsed": (2025, 3, 15, 12, 0, 0, 0, 0, 0),
+            },
+            {
+                "title": "Another Headline",
+                "updated_parsed": (2025, 3, 15, 11, 0, 0, 0, 0, 0),
+            },
+        ]
+        return mock_result
+
+    return _mock
+
+
+@pytest.fixture
+def mock_urllib_open(mock_feed_response):
+    """Create a mock urllib.request.urlopen that returns feed data."""
+
+    def _mock(url):
+        mock_response = MagicMock()
+        mock_response.read.return_value = mock_feed_response
+        return mock_response
+
+    return _mock
+
+
+@pytest.fixture
+def sample_items():
+    """Sample items as returned by fetch module (title, source, timestamp)."""
+    return [
+        ("Headline One", "Test Source", "12:00"),
+        ("Headline Two", "Another Source", "11:30"),
+        ("Headline Three", "Third Source", "10:45"),
+    ]
+
+
+@pytest.fixture
+def sample_config():
+    """Sample config for testing."""
+    from engine.config import Config
+
+    return Config(
+        headline_limit=100,
+        feed_timeout=10,
+        mic_threshold_db=50,
+        mode="news",
+        firehose=False,
+        ntfy_topic="https://ntfy.sh/test/json",
+        ntfy_reconnect_delay=5,
+        message_display_secs=30,
+        font_dir="fonts",
+        font_path="",
+        font_index=0,
+        font_picker=False,
+        font_sz=60,
+        render_h=8,
+        ssaa=4,
+        scroll_dur=5.625,
+        frame_dt=0.05,
+        firehose_h=12,
+        grad_speed=0.08,
+        glitch_glyphs="░▒▓█▌▐",
+        kata_glyphs="ﾊﾐﾋｰｳ",
+        script_fonts={},
+    )
+
+
+@pytest.fixture
+def poetry_config():
+    """Sample config for poetry mode."""
+    from engine.config import Config
+
+    return Config(
+        headline_limit=100,
+        feed_timeout=10,
+        mic_threshold_db=50,
+        mode="poetry",
+        firehose=False,
+        ntfy_topic="https://ntfy.sh/test/json",
+        ntfy_reconnect_delay=5,
+        message_display_secs=30,
+        font_dir="fonts",
+        font_path="",
+        font_index=0,
+        font_picker=False,
+        font_sz=60,
+        render_h=8,
+        ssaa=4,
+        scroll_dur=5.625,
+        frame_dt=0.05,
+        firehose_h=12,
+        grad_speed=0.08,
+        glitch_glyphs="░▒▓█▌▐",
+        kata_glyphs="ﾊﾐﾋｰｳ",
+        script_fonts={},
+    )
+
+
+@pytest.fixture
+def firehose_config():
+    """Sample config with firehose enabled."""
+    from engine.config import Config
+
+    return Config(
+        headline_limit=100,
+        feed_timeout=10,
+        mic_threshold_db=50,
+        mode="news",
+        firehose=True,
+        ntfy_topic="https://ntfy.sh/test/json",
+        ntfy_reconnect_delay=5,
+        message_display_secs=30,
+        font_dir="fonts",
+        font_path="",
+        font_index=0,
+        font_picker=False,
+        font_sz=60,
+        render_h=8,
+        ssaa=4,
+        scroll_dur=5.625,
+        frame_dt=0.05,
+        firehose_h=12,
+        grad_speed=0.08,
+        glitch_glyphs="░▒▓█▌▐",
+        kata_glyphs="ﾊﾐﾋｰｳ",
+        script_fonts={},
+    )

tests/test_config.py

@@ -7,6 +7,8 @@ import tempfile
 from pathlib import Path
 from unittest.mock import patch
 
+import pytest
+
 from engine import config
 
 
@@ -160,3 +162,140 @@ class TestSetFontSelection:
         config.set_font_selection(font_path=None, font_index=None)
         assert original_path == config.FONT_PATH
         assert original_index == config.FONT_INDEX
+
+
+class TestConfigDataclass:
+    """Tests for Config dataclass."""
+
+    def test_config_has_required_fields(self):
+        """Config has all required fields."""
+        c = config.Config()
+        assert hasattr(c, "headline_limit")
+        assert hasattr(c, "feed_timeout")
+        assert hasattr(c, "mic_threshold_db")
+        assert hasattr(c, "mode")
+        assert hasattr(c, "firehose")
+        assert hasattr(c, "ntfy_topic")
+        assert hasattr(c, "ntfy_reconnect_delay")
+        assert hasattr(c, "message_display_secs")
+        assert hasattr(c, "font_dir")
+        assert hasattr(c, "font_path")
+        assert hasattr(c, "font_index")
+        assert hasattr(c, "font_picker")
+        assert hasattr(c, "font_sz")
+        assert hasattr(c, "render_h")
+        assert hasattr(c, "ssaa")
+        assert hasattr(c, "scroll_dur")
+        assert hasattr(c, "frame_dt")
+        assert hasattr(c, "firehose_h")
+        assert hasattr(c, "grad_speed")
+        assert hasattr(c, "glitch_glyphs")
+        assert hasattr(c, "kata_glyphs")
+        assert hasattr(c, "script_fonts")
+
+    def test_config_defaults(self):
+        """Config has sensible defaults."""
+        c = config.Config()
+        assert c.headline_limit == 1000
+        assert c.feed_timeout == 10
+        assert c.mic_threshold_db == 50
+        assert c.mode == "news"
+        assert c.firehose is False
+        assert c.ntfy_reconnect_delay == 5
+        assert c.message_display_secs == 30
+
+    def test_config_is_immutable(self):
+        """Config is frozen (immutable)."""
+        c = config.Config()
+        with pytest.raises(AttributeError):
+            c.headline_limit = 500  # type: ignore
+
+    def test_config_custom_values(self):
+        """Config accepts custom values."""
+        c = config.Config(
+            headline_limit=500,
+            mode="poetry",
+            firehose=True,
+            ntfy_topic="https://ntfy.sh/test",
+        )
+        assert c.headline_limit == 500
+        assert c.mode == "poetry"
+        assert c.firehose is True
+        assert c.ntfy_topic == "https://ntfy.sh/test"
+
+
+class TestConfigFromArgs:
+    """Tests for Config.from_args method."""
+
+    def test_from_args_defaults(self):
+        """from_args creates config with defaults from empty argv."""
+        c = config.Config.from_args(["prog"])
+        assert c.mode == "news"
+        assert c.firehose is False
+        assert c.font_picker is True
+
+    def test_from_args_poetry_mode(self):
+        """from_args detects --poetry flag."""
+        c = config.Config.from_args(["prog", "--poetry"])
+        assert c.mode == "poetry"
+
+    def test_from_args_poetry_short_flag(self):
+        """from_args detects -p short flag."""
+        c = config.Config.from_args(["prog", "-p"])
+        assert c.mode == "poetry"
+
+    def test_from_args_firehose(self):
+        """from_args detects --firehose flag."""
+        c = config.Config.from_args(["prog", "--firehose"])
+        assert c.firehose is True
+
+    def test_from_args_no_font_picker(self):
+        """from_args detects --no-font-picker flag."""
+        c = config.Config.from_args(["prog", "--no-font-picker"])
+        assert c.font_picker is False
+
+    def test_from_args_font_index(self):
+        """from_args parses --font-index."""
+        c = config.Config.from_args(["prog", "--font-index", "3"])
+        assert c.font_index == 3
+
+
+class TestGetSetConfig:
+    """Tests for get_config and set_config functions."""
+
+    def test_get_config_returns_config(self):
+        """get_config returns a Config instance."""
+        c = config.get_config()
+        assert isinstance(c, config.Config)
+
+    def test_set_config_allows_injection(self):
+        """set_config allows injecting a custom config."""
+        custom = config.Config(mode="poetry", headline_limit=100)
+        config.set_config(custom)
+        assert config.get_config().mode == "poetry"
+        assert config.get_config().headline_limit == 100
+
+    def test_set_config_then_get_config(self):
+        """set_config followed by get_config returns the set config."""
+        original = config.get_config()
+        test_config = config.Config(headline_limit=42)
+        config.set_config(test_config)
+        result = config.get_config()
+        assert result.headline_limit == 42
+        config.set_config(original)
+
+
+class TestPlatformFontPaths:
+    """Tests for platform font path detection."""
+
+    def test_get_platform_font_paths_returns_dict(self):
+        """_get_platform_font_paths returns a dictionary."""
+        fonts = config._get_platform_font_paths()
+        assert isinstance(fonts, dict)
+
+    def test_platform_font_paths_common_languages(self):
+        """Common language font mappings exist."""
+        fonts = config._get_platform_font_paths()
+        common = {"ja", "zh-cn", "ko", "ru", "ar", "hi"}
+        found = set(fonts.keys()) & common
+        assert len(found) > 0

tests/test_controller.py

@@ -0,0 +1,117 @@
+"""
+Tests for engine.controller module.
+"""
+
+from unittest.mock import MagicMock, patch
+
+from engine import config
+from engine.controller import StreamController
+
+
+class TestStreamController:
+    """Tests for StreamController class."""
+
+    def test_init_default_config(self):
+        """StreamController initializes with default config."""
+        controller = StreamController()
+        assert controller.config is not None
+        assert isinstance(controller.config, config.Config)
+
+    def test_init_custom_config(self):
+        """StreamController accepts custom config."""
+        custom_config = config.Config(headline_limit=500)
+        controller = StreamController(config=custom_config)
+        assert controller.config.headline_limit == 500
+
+    def test_init_sources_none_by_default(self):
+        """Sources are None until initialized."""
+        controller = StreamController()
+        assert controller.mic is None
+        assert controller.ntfy is None
+
+    @patch("engine.controller.MicMonitor")
+    @patch("engine.controller.NtfyPoller")
+    def test_initialize_sources(self, mock_ntfy, mock_mic):
+        """initialize_sources creates mic and ntfy instances."""
+        mock_mic_instance = MagicMock()
+        mock_mic_instance.available = True
+        mock_mic_instance.start.return_value = True
+        mock_mic.return_value = mock_mic_instance
+
+        mock_ntfy_instance = MagicMock()
+        mock_ntfy_instance.start.return_value = True
+        mock_ntfy.return_value = mock_ntfy_instance
+
+        controller = StreamController()
+        mic_ok, ntfy_ok = controller.initialize_sources()
+
+        assert mic_ok is True
+        assert ntfy_ok is True
+        assert controller.mic is not None
+        assert controller.ntfy is not None
+
+    @patch("engine.controller.MicMonitor")
+    @patch("engine.controller.NtfyPoller")
+    def test_initialize_sources_mic_unavailable(self, mock_ntfy, mock_mic):
+        """initialize_sources handles unavailable mic."""
+        mock_mic_instance = MagicMock()
+        mock_mic_instance.available = False
+        mock_mic.return_value = mock_mic_instance
+
+        mock_ntfy_instance = MagicMock()
+        mock_ntfy_instance.start.return_value = True
+        mock_ntfy.return_value = mock_ntfy_instance
+
+        controller = StreamController()
+        mic_ok, ntfy_ok = controller.initialize_sources()
+
+        assert mic_ok is False
+        assert ntfy_ok is True
+
+
+class TestStreamControllerCleanup:
+    """Tests for StreamController cleanup."""
+
+    @patch("engine.controller.MicMonitor")
+    def test_cleanup_stops_mic(self, mock_mic):
+        """cleanup stops the microphone if running."""
+        mock_mic_instance = MagicMock()
+        mock_mic.return_value = mock_mic_instance
+
+        controller = StreamController()
+        controller.mic = mock_mic_instance
+        controller.cleanup()
+
+        mock_mic_instance.stop.assert_called_once()
+
+
+class TestStreamControllerWarmup:
+    """Tests for StreamController topic warmup."""
+
+    def test_warmup_topics_idempotent(self):
+        """warmup_topics can be called multiple times."""
+        StreamController._topics_warmed = False
+
+        with patch("urllib.request.urlopen") as mock_urlopen:
+            StreamController.warmup_topics()
+            StreamController.warmup_topics()
+
+            assert mock_urlopen.call_count >= 3
+
+    def test_warmup_topics_sets_flag(self):
+        """warmup_topics sets the warmed flag."""
+        StreamController._topics_warmed = False
+
+        with patch("urllib.request.urlopen"):
+            StreamController.warmup_topics()
+
+            assert StreamController._topics_warmed is True
+
+    def test_warmup_topics_skips_after_first(self):
+        """warmup_topics skips after first call."""
+        StreamController._topics_warmed = True
+
+        with patch("urllib.request.urlopen") as mock_urlopen:
+            StreamController.warmup_topics()
+
+            mock_urlopen.assert_not_called()

tests/test_display.py

@@ -0,0 +1,79 @@
+"""
+Tests for engine.display module.
+"""
+
+from engine.display import NullDisplay, TerminalDisplay
+
+
+class TestDisplayProtocol:
+    """Test that display backends satisfy the Display protocol."""
+
+    def test_terminal_display_is_display(self):
+        """TerminalDisplay satisfies Display protocol."""
+        display = TerminalDisplay()
+        assert hasattr(display, "init")
+        assert hasattr(display, "show")
+        assert hasattr(display, "clear")
+        assert hasattr(display, "cleanup")
+
+    def test_null_display_is_display(self):
+        """NullDisplay satisfies Display protocol."""
+        display = NullDisplay()
+        assert hasattr(display, "init")
+        assert hasattr(display, "show")
+        assert hasattr(display, "clear")
+        assert hasattr(display, "cleanup")
+
+
+class TestTerminalDisplay:
+    """Tests for TerminalDisplay class."""
+
+    def test_init_sets_dimensions(self):
+        """init stores terminal dimensions."""
+        display = TerminalDisplay()
+        display.init(80, 24)
+        assert display.width == 80
+        assert display.height == 24
+
+    def test_show_returns_none(self):
+        """show returns None after writing to stdout."""
+        display = TerminalDisplay()
+        display.width = 80
+        display.height = 24
+        display.show(["line1", "line2"])
+
+    def test_clear_does_not_error(self):
+        """clear works without error."""
+        display = TerminalDisplay()
+        display.clear()
+
+    def test_cleanup_does_not_error(self):
+        """cleanup works without error."""
+        display = TerminalDisplay()
+        display.cleanup()
+
+
+class TestNullDisplay:
+    """Tests for NullDisplay class."""
+
+    def test_init_stores_dimensions(self):
+        """init stores dimensions."""
+        display = NullDisplay()
+        display.init(100, 50)
+        assert display.width == 100
+        assert display.height == 50
+
+    def test_show_does_nothing(self):
+        """show discards buffer without error."""
+        display = NullDisplay()
+        display.show(["line1", "line2", "line3"])
+
+    def test_clear_does_nothing(self):
+        """clear does nothing."""
+        display = NullDisplay()
+        display.clear()
+
+    def test_cleanup_does_nothing(self):
+        """cleanup does nothing."""
+        display = NullDisplay()
+        display.cleanup()

tests/test_effects.py

@@ -0,0 +1,427 @@
+"""
+Tests for engine.effects module.
+"""
+
+from engine.effects import EffectChain, EffectConfig, EffectContext, EffectRegistry
+
+
+class MockEffect:
+    name = "mock"
+    config = EffectConfig(enabled=True, intensity=1.0)
+
+    def __init__(self):
+        self.processed = False
+        self.last_ctx = None
+
+    def process(self, buf, ctx):
+        self.processed = True
+        self.last_ctx = ctx
+        return buf + ["processed"]
+
+    def configure(self, config):
+        self.config = config
+
+
+class TestEffectConfig:
+    def test_defaults(self):
+        cfg = EffectConfig()
+        assert cfg.enabled is True
+        assert cfg.intensity == 1.0
+        assert cfg.params == {}
+
+    def test_custom_values(self):
+        cfg = EffectConfig(enabled=False, intensity=0.5, params={"key": "value"})
+        assert cfg.enabled is False
+        assert cfg.intensity == 0.5
+        assert cfg.params == {"key": "value"}
+
+
+class TestEffectContext:
+    def test_defaults(self):
+        ctx = EffectContext(
+            terminal_width=80,
+            terminal_height=24,
+            scroll_cam=0,
+            ticker_height=20,
+            mic_excess=0.0,
+            grad_offset=0.0,
+            frame_number=0,
+            has_message=False,
+        )
+        assert ctx.terminal_width == 80
+        assert ctx.terminal_height == 24
+        assert ctx.ticker_height == 20
+        assert ctx.items == []
+
+    def test_with_items(self):
+        items = [("Title", "Source", "12:00")]
+        ctx = EffectContext(
+            terminal_width=80,
+            terminal_height=24,
+            scroll_cam=0,
+            ticker_height=20,
+            mic_excess=0.0,
+            grad_offset=0.0,
+            frame_number=0,
+            has_message=False,
+            items=items,
+        )
+        assert ctx.items == items
+
+
+class TestEffectRegistry:
+    def test_init_empty(self):
+        registry = EffectRegistry()
+        assert len(registry.list_all()) == 0
+
+    def test_register(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        registry.register(effect)
+        assert "mock" in registry.list_all()
+
+    def test_get(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        registry.register(effect)
+        retrieved = registry.get("mock")
+        assert retrieved is effect
+
+    def test_get_nonexistent(self):
+        registry = EffectRegistry()
+        assert registry.get("nonexistent") is None
+
+    def test_enable(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.config.enabled = False
+        registry.register(effect)
+        registry.enable("mock")
+        assert effect.config.enabled is True
+
+    def test_disable(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.config.enabled = True
+        registry.register(effect)
+        registry.disable("mock")
+        assert effect.config.enabled is False
+
+    def test_list_enabled(self):
+        registry = EffectRegistry()
+
+        class EnabledEffect:
+            name = "enabled_effect"
+            config = EffectConfig(enabled=True, intensity=1.0)
+
+        class DisabledEffect:
+            name = "disabled_effect"
+            config = EffectConfig(enabled=False, intensity=1.0)
+
+        registry.register(EnabledEffect())
+        registry.register(DisabledEffect())
+        enabled = registry.list_enabled()
+        assert len(enabled) == 1
+        assert enabled[0].name == "enabled_effect"
+
+    def test_configure(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        registry.register(effect)
+        new_config = EffectConfig(enabled=False, intensity=0.3)
+        registry.configure("mock", new_config)
+        assert effect.config.enabled is False
+        assert effect.config.intensity == 0.3
+
+    def test_is_enabled(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.config.enabled = True
+        registry.register(effect)
+        assert registry.is_enabled("mock") is True
+        assert registry.is_enabled("nonexistent") is False
+
+
+class TestEffectChain:
+    def test_init(self):
+        registry = EffectRegistry()
+        chain = EffectChain(registry)
+        assert chain.get_order() == []
+
+    def test_set_order(self):
+        registry = EffectRegistry()
+        effect1 = MockEffect()
+        effect1.name = "effect1"
+        effect2 = MockEffect()
+        effect2.name = "effect2"
+        registry.register(effect1)
+        registry.register(effect2)
+        chain = EffectChain(registry)
+        chain.set_order(["effect1", "effect2"])
+        assert chain.get_order() == ["effect1", "effect2"]
+
+    def test_add_effect(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.name = "test_effect"
+        registry.register(effect)
+        chain = EffectChain(registry)
+        chain.add_effect("test_effect")
+        assert "test_effect" in chain.get_order()
+
+    def test_add_effect_invalid(self):
+        registry = EffectRegistry()
+        chain = EffectChain(registry)
+        result = chain.add_effect("nonexistent")
+        assert result is False
+
+    def test_remove_effect(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.name = "test_effect"
+        registry.register(effect)
+        chain = EffectChain(registry)
+        chain.set_order(["test_effect"])
+        chain.remove_effect("test_effect")
+        assert "test_effect" not in chain.get_order()
+
+    def test_reorder(self):
+        registry = EffectRegistry()
+        effect1 = MockEffect()
+        effect1.name = "effect1"
+        effect2 = MockEffect()
+        effect2.name = "effect2"
+        effect3 = MockEffect()
+        effect3.name = "effect3"
+        registry.register(effect1)
+        registry.register(effect2)
+        registry.register(effect3)
+        chain = EffectChain(registry)
+        chain.set_order(["effect1", "effect2", "effect3"])
+        result = chain.reorder(["effect3", "effect1", "effect2"])
+        assert result is True
+        assert chain.get_order() == ["effect3", "effect1", "effect2"]
+
+    def test_reorder_invalid(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.name = "effect1"
+        registry.register(effect)
+        chain = EffectChain(registry)
+        result = chain.reorder(["effect1", "nonexistent"])
+        assert result is False
+
+    def test_process_empty_chain(self):
+        registry = EffectRegistry()
+        chain = EffectChain(registry)
+        buf = ["line1", "line2"]
+        ctx = EffectContext(
+            terminal_width=80,
+            terminal_height=24,
+            scroll_cam=0,
+            ticker_height=20,
+            mic_excess=0.0,
+            grad_offset=0.0,
+            frame_number=0,
+            has_message=False,
+        )
+        result = chain.process(buf, ctx)
+        assert result == buf
+
+    def test_process_with_effects(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.name = "test_effect"
+        registry.register(effect)
+        chain = EffectChain(registry)
+        chain.set_order(["test_effect"])
+        buf = ["line1", "line2"]
+        ctx = EffectContext(
+            terminal_width=80,
+            terminal_height=24,
+            scroll_cam=0,
+            ticker_height=20,
+            mic_excess=0.0,
+            grad_offset=0.0,
+            frame_number=0,
+            has_message=False,
+        )
+        result = chain.process(buf, ctx)
+        assert result == ["line1", "line2", "processed"]
+        assert effect.processed is True
+        assert effect.last_ctx is ctx
+
+    def test_process_disabled_effect(self):
+        registry = EffectRegistry()
+        effect = MockEffect()
+        effect.name = "test_effect"
+        effect.config.enabled = False
+        registry.register(effect)
+        chain = EffectChain(registry)
+        chain.set_order(["test_effect"])
+        buf = ["line1"]
+        ctx = EffectContext(
+            terminal_width=80,
+            terminal_height=24,
+            scroll_cam=0,
+            ticker_height=20,
+            mic_excess=0.0,
+            grad_offset=0.0,
+            frame_number=0,
+            has_message=False,
+        )
+        result = chain.process(buf, ctx)
+        assert result == ["line1"]
+        assert effect.processed is False
+
+
+class TestEffectsExports:
+    def test_all_exports_are_importable(self):
+        """Verify all exports in __all__ can actually be imported."""
+        import engine.effects as effects_module
+
+        for name in effects_module.__all__:
+            getattr(effects_module, name)
+
+
+class TestPerformanceMonitor:
+    def test_empty_stats(self):
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor()
+        stats = monitor.get_stats()
+        assert "error" in stats
+
+    def test_record_and_retrieve(self):
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor()
+        monitor.start_frame(1)
+        monitor.record_effect("test_effect", 1.5, 100, 150)
+        monitor.end_frame(1, 2.0)
+
+        stats = monitor.get_stats()
+        assert "error" not in stats
+        assert stats["frame_count"] == 1
+        assert "test_effect" in stats["effects"]
+
+    def test_multiple_frames(self):
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor(max_frames=3)
+        for i in range(5):
+            monitor.start_frame(i)
+            monitor.record_effect("effect1", 1.0, 100, 100)
+            monitor.record_effect("effect2", 0.5, 100, 100)
+            monitor.end_frame(i, 1.5)
+
+        stats = monitor.get_stats()
+        assert stats["frame_count"] == 3
+        assert "effect1" in stats["effects"]
+        assert "effect2" in stats["effects"]
+
+    def test_reset(self):
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor()
+        monitor.start_frame(1)
+        monitor.record_effect("test", 1.0, 100, 100)
+        monitor.end_frame(1, 1.0)
+
+        monitor.reset()
+        stats = monitor.get_stats()
+        assert "error" in stats
+
+
+class TestEffectPipelinePerformance:
+    def test_pipeline_stays_within_frame_budget(self):
+        """Verify effect pipeline completes within frame budget (33ms for 30fps)."""
+        from engine.effects import (
+            EffectChain,
+            EffectConfig,
+            EffectContext,
+            EffectRegistry,
+        )
+
+        class DummyEffect:
+            name = "dummy"
+            config = EffectConfig(enabled=True, intensity=1.0)
+
+            def process(self, buf, ctx):
+                return [line * 2 for line in buf]
+
+        registry = EffectRegistry()
+        registry.register(DummyEffect())
+
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor(max_frames=10)
+        chain = EffectChain(registry, monitor)
+        chain.set_order(["dummy"])
+
+        buf = ["x" * 80] * 20
+
+        for i in range(10):
+            ctx = EffectContext(
+                terminal_width=80,
+                terminal_height=24,
+                scroll_cam=0,
+                ticker_height=20,
+                mic_excess=0.0,
+                grad_offset=0.0,
+                frame_number=i,
+                has_message=False,
+            )
+            chain.process(buf, ctx)
+
+        stats = monitor.get_stats()
+        assert "error" not in stats
+        assert stats["pipeline"]["max_ms"] < 33.0
+
+    def test_individual_effects_performance(self):
+        """Verify individual effects don't exceed 10ms per frame."""
+        from engine.effects import (
+            EffectChain,
+            EffectConfig,
+            EffectContext,
+            EffectRegistry,
+        )
+
+        class SlowEffect:
+            name = "slow"
+            config = EffectConfig(enabled=True, intensity=1.0)
+
+            def process(self, buf, ctx):
+                result = []
+                for line in buf:
+                    result.append(line)
+                    result.append(line + line)
+                return result
+
+        registry = EffectRegistry()
+        registry.register(SlowEffect())
+
+        from engine.effects.performance import PerformanceMonitor
+
+        monitor = PerformanceMonitor(max_frames=5)
+        chain = EffectChain(registry, monitor)
+        chain.set_order(["slow"])
+
+        buf = ["x" * 80] * 10
+
+        for i in range(5):
+            ctx = EffectContext(
+                terminal_width=80,
+                terminal_height=24,
+                scroll_cam=0,
+                ticker_height=20,
+                mic_excess=0.0,
+                grad_offset=0.0,
+                frame_number=i,
+                has_message=False,
+            )
+            chain.process(buf, ctx)
+
+        stats = monitor.get_stats()
+        assert "error" not in stats
+        assert stats["effects"]["slow"]["max_ms"] < 10.0

tests/test_effects_controller.py

@@ -0,0 +1,117 @@
+"""
+Tests for engine.effects.controller module.
+"""
+
+from unittest.mock import MagicMock, patch
+
+from engine.effects.controller import (
+    handle_effects_command,
+    set_effect_chain_ref,
+)
+
+
+class TestHandleEffectsCommand:
+    """Tests for handle_effects_command function."""
+
+    def test_list_effects(self):
+        """list command returns formatted effects list."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_plugin = MagicMock()
+            mock_plugin.config.enabled = True
+            mock_plugin.config.intensity = 0.5
+            mock_registry.return_value.list_all.return_value = {"noise": mock_plugin}
+
+            with patch("engine.effects.controller._get_effect_chain") as mock_chain:
+                mock_chain.return_value.get_order.return_value = ["noise"]
+
+                result = handle_effects_command("/effects list")
+
+                assert "noise: ON" in result
+                assert "intensity=0.5" in result
+
+    def test_enable_effect(self):
+        """enable command calls registry.enable."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_plugin = MagicMock()
+            mock_registry.return_value.get.return_value = mock_plugin
+            mock_registry.return_value.list_all.return_value = {"noise": mock_plugin}
+
+            result = handle_effects_command("/effects noise on")
+
+            assert "Enabled: noise" in result
+            mock_registry.return_value.enable.assert_called_once_with("noise")
+
+    def test_disable_effect(self):
+        """disable command calls registry.disable."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_plugin = MagicMock()
+            mock_registry.return_value.get.return_value = mock_plugin
+            mock_registry.return_value.list_all.return_value = {"noise": mock_plugin}
+
+            result = handle_effects_command("/effects noise off")
+
+            assert "Disabled: noise" in result
+            mock_registry.return_value.disable.assert_called_once_with("noise")
+
+    def test_set_intensity(self):
+        """intensity command sets plugin intensity."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_plugin = MagicMock()
+            mock_plugin.config.intensity = 0.5
+            mock_registry.return_value.get.return_value = mock_plugin
+            mock_registry.return_value.list_all.return_value = {"noise": mock_plugin}
+
+            result = handle_effects_command("/effects noise intensity 0.8")
+
+            assert "intensity to 0.8" in result
+            assert mock_plugin.config.intensity == 0.8
+
+    def test_invalid_intensity_range(self):
+        """intensity outside 0.0-1.0 returns error."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_plugin = MagicMock()
+            mock_registry.return_value.get.return_value = mock_plugin
+            mock_registry.return_value.list_all.return_value = {"noise": mock_plugin}
+
+            result = handle_effects_command("/effects noise intensity 1.5")
+
+            assert "between 0.0 and 1.0" in result
+
+    def test_reorder_pipeline(self):
+        """reorder command calls chain.reorder."""
+        with patch("engine.effects.controller.get_registry") as mock_registry:
+            mock_registry.return_value.list_all.return_value = {}
+
+            with patch("engine.effects.controller._get_effect_chain") as mock_chain:
+                mock_chain_instance = MagicMock()
+                mock_chain_instance.reorder.return_value = True
+                mock_chain.return_value = mock_chain_instance
+
+                result = handle_effects_command("/effects reorder noise,fade")
+
+                assert "Reordered pipeline" in result
+                mock_chain_instance.reorder.assert_called_once_with(["noise", "fade"])
+
+    def test_unknown_command(self):
+        """unknown command returns error."""
+        result = handle_effects_command("/unknown")
+        assert "Unknown command" in result
+
+    def test_non_effects_command(self):
+        """non-effects command returns error."""
+        result = handle_effects_command("not a command")
+        assert "Unknown command" in result
+
+
+class TestSetEffectChainRef:
+    """Tests for set_effect_chain_ref function."""
+
+    def test_sets_global_ref(self):
+        """set_effect_chain_ref updates global reference."""
+        mock_chain = MagicMock()
+        set_effect_chain_ref(mock_chain)
+
+        from engine.effects.controller import _get_effect_chain
+
+        result = _get_effect_chain()
+        assert result == mock_chain

tests/test_emitters.py

@@ -0,0 +1,69 @@
+"""
+Tests for engine.emitters module.
+"""
+
+from engine.emitters import EventEmitter, Startable, Stoppable
+
+
+class TestEventEmitterProtocol:
+    """Tests for EventEmitter protocol."""
+
+    def test_protocol_exists(self):
+        """EventEmitter protocol is defined."""
+        assert EventEmitter is not None
+
+    def test_protocol_has_subscribe_method(self):
+        """EventEmitter has subscribe method in protocol."""
+        assert hasattr(EventEmitter, "subscribe")
+
+    def test_protocol_has_unsubscribe_method(self):
+        """EventEmitter has unsubscribe method in protocol."""
+        assert hasattr(EventEmitter, "unsubscribe")
+
+
+class TestStartableProtocol:
+    """Tests for Startable protocol."""
+
+    def test_protocol_exists(self):
+        """Startable protocol is defined."""
+        assert Startable is not None
+
+    def test_protocol_has_start_method(self):
+        """Startable has start method in protocol."""
+        assert hasattr(Startable, "start")
+
+
+class TestStoppableProtocol:
+    """Tests for Stoppable protocol."""
+
+    def test_protocol_exists(self):
+        """Stoppable protocol is defined."""
+        assert Stoppable is not None
+
+    def test_protocol_has_stop_method(self):
+        """Stoppable has stop method in protocol."""
+        assert hasattr(Stoppable, "stop")
+
+
+class TestProtocolCompliance:
+    """Tests that existing classes comply with protocols."""
+
+    def test_ntfy_poller_complies_with_protocol(self):
+        """NtfyPoller implements EventEmitter protocol."""
+        from engine.ntfy import NtfyPoller
+
+        poller = NtfyPoller("http://example.com/topic")
+        assert hasattr(poller, "subscribe")
+        assert hasattr(poller, "unsubscribe")
+        assert callable(poller.subscribe)
+        assert callable(poller.unsubscribe)
+
+    def test_mic_monitor_complies_with_protocol(self):
+        """MicMonitor implements EventEmitter and Startable protocols."""
+        from engine.mic import MicMonitor
+
+        monitor = MicMonitor()
+        assert hasattr(monitor, "subscribe")
+        assert hasattr(monitor, "unsubscribe")
+        assert hasattr(monitor, "start")
+        assert hasattr(monitor, "stop")

tests/test_eventbus.py

@@ -0,0 +1,202 @@
+"""
+Tests for engine.eventbus module.
+"""
+
+
+from engine.eventbus import EventBus, get_event_bus, set_event_bus
+from engine.events import EventType, NtfyMessageEvent
+
+
+class TestEventBusInit:
+    """Tests for EventBus initialization."""
+
+    def test_init_creates_empty_subscribers(self):
+        """EventBus starts with no subscribers."""
+        bus = EventBus()
+        assert bus.subscriber_count() == 0
+
+
+class TestEventBusSubscribe:
+    """Tests for EventBus.subscribe method."""
+
+    def test_subscribe_adds_callback(self):
+        """subscribe() adds a callback for an event type."""
+        bus = EventBus()
+        def callback(e):
+            return None
+
+        bus.subscribe(EventType.NTFY_MESSAGE, callback)
+
+        assert bus.subscriber_count(EventType.NTFY_MESSAGE) == 1
+
+    def test_subscribe_multiple_callbacks_same_event(self):
+        """Multiple callbacks can be subscribed to the same event type."""
+        bus = EventBus()
+        def cb1(e):
+            return None
+        def cb2(e):
+            return None
+
+        bus.subscribe(EventType.NTFY_MESSAGE, cb1)
+        bus.subscribe(EventType.NTFY_MESSAGE, cb2)
+
+        assert bus.subscriber_count(EventType.NTFY_MESSAGE) == 2
+
+    def test_subscribe_different_event_types(self):
+        """Callbacks can be subscribed to different event types."""
+        bus = EventBus()
+        def cb1(e):
+            return None
+        def cb2(e):
+            return None
+
+        bus.subscribe(EventType.NTFY_MESSAGE, cb1)
+        bus.subscribe(EventType.MIC_LEVEL, cb2)
+
+        assert bus.subscriber_count(EventType.NTFY_MESSAGE) == 1
+        assert bus.subscriber_count(EventType.MIC_LEVEL) == 1
+
+
+class TestEventBusUnsubscribe:
+    """Tests for EventBus.unsubscribe method."""
+
+    def test_unsubscribe_removes_callback(self):
+        """unsubscribe() removes a callback."""
+        bus = EventBus()
+        def callback(e):
+            return None
+
+        bus.subscribe(EventType.NTFY_MESSAGE, callback)
+        bus.unsubscribe(EventType.NTFY_MESSAGE, callback)
+
+        assert bus.subscriber_count(EventType.NTFY_MESSAGE) == 0
+
+    def test_unsubscribe_nonexistent_callback_no_error(self):
+        """unsubscribe() handles non-existent callback gracefully."""
+        bus = EventBus()
+        def callback(e):
+            return None
+
+        bus.unsubscribe(EventType.NTFY_MESSAGE, callback)
+
+
+class TestEventBusPublish:
+    """Tests for EventBus.publish method."""
+
+    def test_publish_calls_subscriber(self):
+        """publish() calls the subscriber callback."""
+        bus = EventBus()
+        received = []
+
+        def callback(event):
+            received.append(event)
+
+        bus.subscribe(EventType.NTFY_MESSAGE, callback)
+        event = NtfyMessageEvent(title="Test", body="Body")
+        bus.publish(EventType.NTFY_MESSAGE, event)
+
+        assert len(received) == 1
+        assert received[0].title == "Test"
+
+    def test_publish_multiple_subscribers(self):
+        """publish() calls all subscribers for an event type."""
+        bus = EventBus()
+        received1 = []
+        received2 = []
+
+        def callback1(event):
+            received1.append(event)
+
+        def callback2(event):
+            received2.append(event)
+
+        bus.subscribe(EventType.NTFY_MESSAGE, callback1)
+        bus.subscribe(EventType.NTFY_MESSAGE, callback2)
+        event = NtfyMessageEvent(title="Test", body="Body")
+        bus.publish(EventType.NTFY_MESSAGE, event)
+
+        assert len(received1) == 1
+        assert len(received2) == 1
+
+    def test_publish_different_event_types(self):
+        """publish() only calls subscribers for the specific event type."""
+        bus = EventBus()
+        ntfy_received = []
+        mic_received = []
+
+        def ntfy_callback(event):
+            ntfy_received.append(event)
+
+        def mic_callback(event):
+            mic_received.append(event)
+
+        bus.subscribe(EventType.NTFY_MESSAGE, ntfy_callback)
+        bus.subscribe(EventType.MIC_LEVEL, mic_callback)
+        event = NtfyMessageEvent(title="Test", body="Body")
+        bus.publish(EventType.NTFY_MESSAGE, event)
+
+        assert len(ntfy_received) == 1
+        assert len(mic_received) == 0
+
+
+class TestEventBusClear:
+    """Tests for EventBus.clear method."""
+
+    def test_clear_removes_all_subscribers(self):
+        """clear() removes all subscribers."""
+        bus = EventBus()
+        def cb1(e):
+            return None
+        def cb2(e):
+            return None
+
+        bus.subscribe(EventType.NTFY_MESSAGE, cb1)
+        bus.subscribe(EventType.MIC_LEVEL, cb2)
+        bus.clear()
+
+        assert bus.subscriber_count() == 0
+
+
+class TestEventBusThreadSafety:
+    """Tests for EventBus thread safety."""
+
+    def test_concurrent_subscribe_unsubscribe(self):
+        """subscribe and unsubscribe can be called concurrently."""
+        import threading
+
+        bus = EventBus()
+        callbacks = [lambda e: None for _ in range(10)]
+
+        def subscribe():
+            for cb in callbacks:
+                bus.subscribe(EventType.NTFY_MESSAGE, cb)
+
+        def unsubscribe():
+            for cb in callbacks:
+                bus.unsubscribe(EventType.NTFY_MESSAGE, cb)
+
+        t1 = threading.Thread(target=subscribe)
+        t2 = threading.Thread(target=unsubscribe)
+        t1.start()
+        t2.start()
+        t1.join()
+        t2.join()
+
+
+class TestGlobalEventBus:
+    """Tests for global event bus functions."""
+
+    def test_get_event_bus_returns_singleton(self):
+        """get_event_bus() returns the same instance."""
+        bus1 = get_event_bus()
+        bus2 = get_event_bus()
+        assert bus1 is bus2
+
+    def test_set_event_bus_replaces_singleton(self):
+        """set_event_bus() replaces the global event bus."""
+        new_bus = EventBus()
+        set_event_bus(new_bus)
+        try:
+            assert get_event_bus() is new_bus
+        finally:
+            set_event_bus(None)

tests/test_events.py

@@ -0,0 +1,112 @@
+"""
+Tests for engine.events module.
+"""
+
+from datetime import datetime
+
+from engine import events
+
+
+class TestEventType:
+    """Tests for EventType enum."""
+
+    def test_event_types_exist(self):
+        """All expected event types exist."""
+        assert hasattr(events.EventType, "NEW_HEADLINE")
+        assert hasattr(events.EventType, "FRAME_TICK")
+        assert hasattr(events.EventType, "MIC_LEVEL")
+        assert hasattr(events.EventType, "NTFY_MESSAGE")
+        assert hasattr(events.EventType, "STREAM_START")
+        assert hasattr(events.EventType, "STREAM_END")
+
+
+class TestHeadlineEvent:
+    """Tests for HeadlineEvent dataclass."""
+
+    def test_create_headline_event(self):
+        """HeadlineEvent can be created with required fields."""
+        e = events.HeadlineEvent(
+            title="Test Headline",
+            source="Test Source",
+            timestamp="12:00",
+        )
+        assert e.title == "Test Headline"
+        assert e.source == "Test Source"
+        assert e.timestamp == "12:00"
+
+    def test_headline_event_optional_language(self):
+        """HeadlineEvent supports optional language field."""
+        e = events.HeadlineEvent(
+            title="Test",
+            source="Test",
+            timestamp="12:00",
+            language="ja",
+        )
+        assert e.language == "ja"
+
+
+class TestFrameTickEvent:
+    """Tests for FrameTickEvent dataclass."""
+
+    def test_create_frame_tick_event(self):
+        """FrameTickEvent can be created."""
+        now = datetime.now()
+        e = events.FrameTickEvent(
+            frame_number=100,
+            timestamp=now,
+            delta_seconds=0.05,
+        )
+        assert e.frame_number == 100
+        assert e.timestamp == now
+        assert e.delta_seconds == 0.05
+
+
+class TestMicLevelEvent:
+    """Tests for MicLevelEvent dataclass."""
+
+    def test_create_mic_level_event(self):
+        """MicLevelEvent can be created."""
+        now = datetime.now()
+        e = events.MicLevelEvent(
+            db_level=60.0,
+            excess_above_threshold=10.0,
+            timestamp=now,
+        )
+        assert e.db_level == 60.0
+        assert e.excess_above_threshold == 10.0
+
+
+class TestNtfyMessageEvent:
+    """Tests for NtfyMessageEvent dataclass."""
+
+    def test_create_ntfy_message_event(self):
+        """NtfyMessageEvent can be created with required fields."""
+        e = events.NtfyMessageEvent(
+            title="Test Title",
+            body="Test Body",
+        )
+        assert e.title == "Test Title"
+        assert e.body == "Test Body"
+        assert e.message_id is None
+
+    def test_ntfy_message_event_with_id(self):
+        """NtfyMessageEvent supports optional message_id."""
+        e = events.NtfyMessageEvent(
+            title="Test",
+            body="Test",
+            message_id="abc123",
+        )
+        assert e.message_id == "abc123"
+
+
+class TestStreamEvent:
+    """Tests for StreamEvent dataclass."""
+
+    def test_create_stream_event(self):
+        """StreamEvent can be created."""
+        e = events.StreamEvent(
+            event_type=events.EventType.STREAM_START,
+            headline_count=100,
+        )
+        assert e.event_type == events.EventType.STREAM_START
+        assert e.headline_count == 100

tests/test_frame.py

@@ -0,0 +1,63 @@
+"""
+Tests for engine.frame module.
+"""
+
+import time
+
+from engine.frame import FrameTimer, calculate_scroll_step
+
+
+class TestFrameTimer:
+    """Tests for FrameTimer class."""
+
+    def test_init_default(self):
+        """FrameTimer initializes with default values."""
+        timer = FrameTimer()
+        assert timer.target_frame_dt == 0.05
+        assert timer.fps >= 0
+
+    def test_init_custom(self):
+        """FrameTimer accepts custom frame duration."""
+        timer = FrameTimer(target_frame_dt=0.1)
+        assert timer.target_frame_dt == 0.1
+
+    def test_fps_calculation(self):
+        """FrameTimer calculates FPS correctly."""
+        timer = FrameTimer()
+        timer._frame_count = 10
+        timer._start_time = time.monotonic() - 1.0
+        assert timer.fps >= 9.0
+
+    def test_reset(self):
+        """FrameTimer.reset() clears frame count."""
+        timer = FrameTimer()
+        timer._frame_count = 100
+        timer.reset()
+        assert timer._frame_count == 0
+
+
+class TestCalculateScrollStep:
+    """Tests for calculate_scroll_step function."""
+
+    def test_basic_calculation(self):
+        """calculate_scroll_step returns positive value."""
+        result = calculate_scroll_step(5.0, 24)
+        assert result > 0
+
+    def test_with_padding(self):
+        """calculate_scroll_step respects padding parameter."""
+        without_padding = calculate_scroll_step(5.0, 24, padding=0)
+        with_padding = calculate_scroll_step(5.0, 24, padding=15)
+        assert with_padding < without_padding
+
+    def test_larger_view_slower_scroll(self):
+        """Larger view height results in slower scroll steps."""
+        small = calculate_scroll_step(5.0, 10)
+        large = calculate_scroll_step(5.0, 50)
+        assert large < small
+
+    def test_longer_duration_slower_scroll(self):
+        """Longer scroll duration results in slower scroll steps."""
+        fast = calculate_scroll_step(2.0, 24)
+        slow = calculate_scroll_step(10.0, 24)
+        assert slow > fast

tests/test_layers.py

@@ -0,0 +1,96 @@
+"""
+Tests for engine.layers module.
+"""
+
+import time
+
+from engine import layers
+
+
+class TestRenderMessageOverlay:
+    """Tests for render_message_overlay function."""
+
+    def test_no_message_returns_empty(self):
+        """Returns empty list when msg is None."""
+        result, cache = layers.render_message_overlay(None, 80, 24, (None, None))
+        assert result == []
+        assert cache[0] is None
+
+    def test_message_returns_overlay_lines(self):
+        """Returns non-empty list when message is present."""
+        msg = ("Test Title", "Test Body", time.monotonic())
+        result, cache = layers.render_message_overlay(msg, 80, 24, (None, None))
+        assert len(result) > 0
+        assert cache[0] is not None
+
+    def test_cache_key_changes_with_text(self):
+        """Cache key changes when message text changes."""
+        msg1 = ("Title1", "Body1", time.monotonic())
+        msg2 = ("Title2", "Body2", time.monotonic())
+
+        _, cache1 = layers.render_message_overlay(msg1, 80, 24, (None, None))
+        _, cache2 = layers.render_message_overlay(msg2, 80, 24, cache1)
+
+        assert cache1[0] != cache2[0]
+
+    def test_cache_reuse_avoids_recomputation(self):
+        """Cache is returned when same message is passed (interface test)."""
+        msg = ("Same Title", "Same Body", time.monotonic())
+
+        result1, cache1 = layers.render_message_overlay(msg, 80, 24, (None, None))
+        result2, cache2 = layers.render_message_overlay(msg, 80, 24, cache1)
+
+        assert len(result1) > 0
+        assert len(result2) > 0
+        assert cache1[0] == cache2[0]
+
+
+class TestRenderFirehose:
+    """Tests for render_firehose function."""
+
+    def test_no_firehose_returns_empty(self):
+        """Returns empty list when firehose height is 0."""
+        items = [("Headline", "Source", "12:00")]
+        result = layers.render_firehose(items, 80, 0, 24)
+        assert result == []
+
+    def test_firehose_returns_lines(self):
+        """Returns lines when firehose height > 0."""
+        items = [("Headline", "Source", "12:00")]
+        result = layers.render_firehose(items, 80, 4, 24)
+        assert len(result) == 4
+
+    def test_firehose_includes_ansi_escapes(self):
+        """Returns lines containing ANSI escape sequences."""
+        items = [("Headline", "Source", "12:00")]
+        result = layers.render_firehose(items, 80, 1, 24)
+        assert "\033[" in result[0]
+
+
+class TestApplyGlitch:
+    """Tests for apply_glitch function."""
+
+    def test_empty_buffer_unchanged(self):
+        """Empty buffer is returned unchanged."""
+        result = layers.apply_glitch([], 0, 0.0, 80)
+        assert result == []
+
+    def test_buffer_length_preserved(self):
+        """Buffer length is preserved after glitch application."""
+        buf = [f"\033[{i + 1};1Htest\033[K" for i in range(10)]
+        result = layers.apply_glitch(buf, 0, 0.5, 80)
+        assert len(result) == len(buf)
+
+
+class TestRenderTickerZone:
+    """Tests for render_ticker_zone function - focusing on interface."""
+
+    def test_returns_list(self):
+        """Returns a list of strings."""
+        result, cache = layers.render_ticker_zone([], 0, 10, 80, {}, 0.0)
+        assert isinstance(result, list)
+
+    def test_returns_dict_for_cache(self):
+        """Returns a dict for the noise cache."""
+        result, cache = layers.render_ticker_zone([], 0, 10, 80, {}, 0.0)
+        assert isinstance(cache, dict)

tests/test_mic.py

@@ -2,8 +2,11 @@
 Tests for engine.mic module.
 """
 
+from datetime import datetime
 from unittest.mock import patch
 
+from engine.events import MicLevelEvent
+
 
 class TestMicMonitorImport:
     """Tests for module import behavior."""
@@ -81,3 +84,66 @@ class TestMicMonitorStop:
         monitor = MicMonitor()
         monitor.stop()
         assert monitor._stream is None
+
+
+class TestMicMonitorEventEmission:
+    """Tests for MicMonitor event emission."""
+
+    def test_subscribe_adds_callback(self):
+        """subscribe() adds a callback."""
+        from engine.mic import MicMonitor
+
+        monitor = MicMonitor()
+        def callback(e):
+            return None
+
+        monitor.subscribe(callback)
+
+        assert callback in monitor._subscribers
+
+    def test_unsubscribe_removes_callback(self):
+        """unsubscribe() removes a callback."""
+        from engine.mic import MicMonitor
+
+        monitor = MicMonitor()
+        def callback(e):
+            return None
+        monitor.subscribe(callback)
+
+        monitor.unsubscribe(callback)
+
+        assert callback not in monitor._subscribers
+
+    def test_emit_calls_subscribers(self):
+        """_emit() calls all subscribers."""
+        from engine.mic import MicMonitor
+
+        monitor = MicMonitor()
+        received = []
+
+        def callback(event):
+            received.append(event)
+
+        monitor.subscribe(callback)
+        event = MicLevelEvent(
+            db_level=60.0, excess_above_threshold=10.0, timestamp=datetime.now()
+        )
+        monitor._emit(event)
+
+        assert len(received) == 1
+        assert received[0].db_level == 60.0
+
+    def test_emit_handles_subscriber_exception(self):
+        """_emit() handles exceptions in subscribers gracefully."""
+        from engine.mic import MicMonitor
+
+        monitor = MicMonitor()
+
+        def bad_callback(event):
+            raise RuntimeError("test")
+
+        monitor.subscribe(bad_callback)
+        event = MicLevelEvent(
+            db_level=60.0, excess_above_threshold=10.0, timestamp=datetime.now()
+        )
+        monitor._emit(event)

tests/test_ntfy.py

@@ -5,6 +5,7 @@ Tests for engine.ntfy module.
 import time
 from unittest.mock import MagicMock, patch
 
+from engine.events import NtfyMessageEvent
 from engine.ntfy import NtfyPoller
 
 
@@ -68,3 +69,54 @@ class TestNtfyPollerDismiss:
             poller.dismiss()
 
             assert poller._message is None
+
+
+class TestNtfyPollerEventEmission:
+    """Tests for NtfyPoller event emission."""
+
+    def test_subscribe_adds_callback(self):
+        """subscribe() adds a callback."""
+        poller = NtfyPoller("http://example.com/topic")
+        def callback(e):
+            return None
+
+        poller.subscribe(callback)
+
+        assert callback in poller._subscribers
+
+    def test_unsubscribe_removes_callback(self):
+        """unsubscribe() removes a callback."""
+        poller = NtfyPoller("http://example.com/topic")
+        def callback(e):
+            return None
+        poller.subscribe(callback)
+
+        poller.unsubscribe(callback)
+
+        assert callback not in poller._subscribers
+
+    def test_emit_calls_subscribers(self):
+        """_emit() calls all subscribers."""
+        poller = NtfyPoller("http://example.com/topic")
+        received = []
+
+        def callback(event):
+            received.append(event)
+
+        poller.subscribe(callback)
+        event = NtfyMessageEvent(title="Test", body="Body")
+        poller._emit(event)
+
+        assert len(received) == 1
+        assert received[0].title == "Test"
+
+    def test_emit_handles_subscriber_exception(self):
+        """_emit() handles exceptions in subscribers gracefully."""
+        poller = NtfyPoller("http://example.com/topic")
+
+        def bad_callback(event):
+            raise RuntimeError("test")
+
+        poller.subscribe(bad_callback)
+        event = NtfyMessageEvent(title="Test", body="Body")
+        poller._emit(event)

tests/test_types.py

@@ -0,0 +1,95 @@
+"""
+Tests for engine.types module.
+"""
+
+from engine.types import (
+    Block,
+    FetchResult,
+    HeadlineItem,
+    items_to_tuples,
+    tuples_to_items,
+)
+
+
+class TestHeadlineItem:
+    """Tests for HeadlineItem dataclass."""
+
+    def test_create_headline_item(self):
+        """Can create HeadlineItem with required fields."""
+        item = HeadlineItem(title="Test", source="Source", timestamp="12:00")
+        assert item.title == "Test"
+        assert item.source == "Source"
+        assert item.timestamp == "12:00"
+
+    def test_to_tuple(self):
+        """to_tuple returns correct tuple."""
+        item = HeadlineItem(title="Test", source="Source", timestamp="12:00")
+        assert item.to_tuple() == ("Test", "Source", "12:00")
+
+    def test_from_tuple(self):
+        """from_tuple creates HeadlineItem from tuple."""
+        item = HeadlineItem.from_tuple(("Test", "Source", "12:00"))
+        assert item.title == "Test"
+        assert item.source == "Source"
+        assert item.timestamp == "12:00"
+
+
+class TestItemsConversion:
+    """Tests for list conversion functions."""
+
+    def test_items_to_tuples(self):
+        """Converts list of HeadlineItem to list of tuples."""
+        items = [
+            HeadlineItem(title="A", source="S", timestamp="10:00"),
+            HeadlineItem(title="B", source="T", timestamp="11:00"),
+        ]
+        result = items_to_tuples(items)
+        assert result == [("A", "S", "10:00"), ("B", "T", "11:00")]
+
+    def test_tuples_to_items(self):
+        """Converts list of tuples to list of HeadlineItem."""
+        tuples = [("A", "S", "10:00"), ("B", "T", "11:00")]
+        result = tuples_to_items(tuples)
+        assert len(result) == 2
+        assert result[0].title == "A"
+        assert result[1].title == "B"
+
+
+class TestFetchResult:
+    """Tests for FetchResult dataclass."""
+
+    def test_create_fetch_result(self):
+        """Can create FetchResult."""
+        items = [HeadlineItem(title="Test", source="Source", timestamp="12:00")]
+        result = FetchResult(items=items, linked=1, failed=0)
+        assert len(result.items) == 1
+        assert result.linked == 1
+        assert result.failed == 0
+
+    def test_to_legacy_tuple(self):
+        """to_legacy_tuple returns correct format."""
+        items = [HeadlineItem(title="Test", source="Source", timestamp="12:00")]
+        result = FetchResult(items=items, linked=1, failed=0)
+        legacy = result.to_legacy_tuple()
+        assert legacy[0] == [("Test", "Source", "12:00")]
+        assert legacy[1] == 1
+        assert legacy[2] == 0
+
+
+class TestBlock:
+    """Tests for Block dataclass."""
+
+    def test_create_block(self):
+        """Can create Block."""
+        block = Block(
+            content=["line1", "line2"], color="\033[38;5;46m", meta_row_index=1
+        )
+        assert len(block.content) == 2
+        assert block.color == "\033[38;5;46m"
+        assert block.meta_row_index == 1
+
+    def test_to_legacy_tuple(self):
+        """to_legacy_tuple returns correct format."""
+        block = Block(content=["line1"], color="green", meta_row_index=0)
+        legacy = block.to_legacy_tuple()
+        assert legacy == (["line1"], "green", 0)

tests/test_viewport.py

@@ -0,0 +1,64 @@
+"""
+Tests for engine.viewport module.
+"""
+
+from engine import viewport
+
+
+class TestViewportTw:
+    """Tests for tw() function."""
+
+    def test_tw_returns_int(self):
+        """tw() returns an integer."""
+        result = viewport.tw()
+        assert isinstance(result, int)
+
+    def test_tw_positive(self):
+        """tw() returns a positive value."""
+        assert viewport.tw() > 0
+
+
+class TestViewportTh:
+    """Tests for th() function."""
+
+    def test_th_returns_int(self):
+        """th() returns an integer."""
+        result = viewport.th()
+        assert isinstance(result, int)
+
+    def test_th_positive(self):
+        """th() returns a positive value."""
+        assert viewport.th() > 0
+
+
+class TestViewportMoveTo:
+    """Tests for move_to() function."""
+
+    def test_move_to_format(self):
+        """move_to() returns correctly formatted ANSI escape."""
+        result = viewport.move_to(5, 10)
+        assert result == "\033[5;10H"
+
+    def test_move_to_default_col(self):
+        """move_to() defaults to column 1."""
+        result = viewport.move_to(5)
+        assert result == "\033[5;1H"
+
+
+class TestViewportClearScreen:
+    """Tests for clear_screen() function."""
+
+    def test_clear_screen_format(self):
+        """clear_screen() returns clear screen ANSI escape."""
+        result = viewport.clear_screen()
+        assert "\033[2J" in result
+        assert "\033[H" in result
+
+
+class TestViewportClearLine:
+    """Tests for clear_line() function."""
+
+    def test_clear_line_format(self):
+        """clear_line() returns clear line ANSI escape."""
+        result = viewport.clear_line()
+        assert result == "\033[K"