diff --git a/js/db.js b/js/db.js
index 95c306b..acd548e 100644
--- a/js/db.js
+++ b/js/db.js
@@ -102,8 +102,6 @@ export class MusicDatabase {
     async addToHistory(track) {
         const storeName = 'history_tracks';
         const minified = this._minifyItem(track.type || 'track', track);
-        const timestamp = Date.now();
-        const entry = { ...minified, timestamp };
 
         const db = await this.open();
 
@@ -112,25 +110,34 @@ export class MusicDatabase {
             const store = transaction.objectStore(storeName);
             const index = store.index('timestamp');
 
-            const cursorReq = index.openCursor(null, 'prev');
+            const lastReq = index.openCursor(null, 'prev');
+            let lastTimestamp = 0;
 
-            cursorReq.onsuccess = (e) => {
+            lastReq.onsuccess = (e) => {
                 const cursor = e.target.result;
-                if (cursor) {
-                    const lastTrack = cursor.value;
-                    if (lastTrack.id === track.id) {
-                        store.delete(cursor.primaryKey);
-                    }
+                if (cursor && lastTimestamp === 0) {
+                    lastTimestamp = cursor.value.timestamp;
                 }
-                store.put(entry);
+
+                const timestamp = Math.max(Date.now(), lastTimestamp + 1);
+                const entry = { ...minified, timestamp };
+
+                const dedupeReq = index.openCursor(null, 'prev');
+                dedupeReq.onsuccess = (e2) => {
+                    const dedupeCursor = e2.target.result;
+                    if (dedupeCursor) {
+                        const trackInHistory = dedupeCursor.value;
+                        if (trackInHistory.id === track.id) {
+                            store.delete(dedupeCursor.primaryKey);
+                        }
+                        dedupeCursor.continue();
+                    } else {
+                        store.put(entry);
+                        resolve(entry);
+                    }
+                };
             };
 
-            cursorReq.onerror = (_e) => {
-                // If cursor fails, just try to put (fallback)
-                store.put(entry);
-            };
-
-            transaction.oncomplete = () => resolve(entry);
             transaction.onerror = (e) => reject(e.target.error);
         });
     }
diff --git a/js/player.js b/js/player.js
index 81f57fe..508e9d5 100644
--- a/js/player.js
+++ b/js/player.js
@@ -291,7 +291,8 @@ export class Player {
     }
 
     setPlaybackSpeed(speed) {
-        const validSpeed = Math.max(0.01, Math.min(100, parseFloat(speed) || 1.0));
+        const parsed = parseFloat(speed);
+        const validSpeed = Math.max(0.01, Math.min(100, isNaN(parsed) ? 1.0 : parsed));
         audioEffectsSettings.setSpeed(validSpeed);
         this.applyAudioEffects();
     }
diff --git a/js/storage.js b/js/storage.js
index 222fa10..f702eac 100644
--- a/js/storage.js
+++ b/js/storage.js
@@ -1830,7 +1830,8 @@ export const audioEffectsSettings = {
     },
 
     setSpeed(speed) {
-        const validSpeed = Math.max(0.01, Math.min(100, parseFloat(speed) || 1.0));
+        const parsed = parseFloat(speed);
+        const validSpeed = Math.max(0.01, Math.min(100, isNaN(parsed) ? 1.0 : parsed));
         localStorage.setItem(this.SPEED_KEY, validSpeed.toString());
     },
 
diff --git a/js/tests/db.test.js b/js/tests/db.test.js
new file mode 100644
index 0000000..8f24d57
--- /dev/null
+++ b/js/tests/db.test.js
@@ -0,0 +1,107 @@
+import { expect, test, describe, beforeEach, afterEach, vi } from 'vitest';
+import { MusicDatabase } from '../db.js';
+
+describe('MusicDatabase', () => {
+    let db;
+    const TEST_DB_NAME = 'TestMonochromeDB';
+
+    beforeEach(async () => {
+        db = new MusicDatabase();
+        db.dbName = TEST_DB_NAME;
+        const req = indexedDB.deleteDatabase(TEST_DB_NAME);
+        await new Promise((resolve) => {
+            req.onsuccess = resolve;
+            req.onerror = resolve;
+        });
+    });
+
+    afterEach(async () => {
+        if (db.db) {
+            db.db.close();
+        }
+        const req = indexedDB.deleteDatabase(TEST_DB_NAME);
+        await new Promise((resolve) => {
+            req.onsuccess = resolve;
+            req.onerror = resolve;
+        });
+    });
+
+    test('opens database and creates stores', async () => {
+        const openedDb = await db.open();
+        expect(openedDb.name).toBe(TEST_DB_NAME);
+        expect(openedDb.objectStoreNames.contains('favorites_tracks')).toBe(true);
+        expect(openedDb.objectStoreNames.contains('history_tracks')).toBe(true);
+        expect(openedDb.objectStoreNames.contains('user_playlists')).toBe(true);
+    });
+
+    test('toggleFavorite adds and removes items', async () => {
+        const track = { id: 'track1', title: 'Test Track', artist: { name: 'Artist' } };
+
+        const added = await db.toggleFavorite('track', track);
+        expect(added).toBe(true);
+        const favorites = await db.getFavorites('track');
+        expect(favorites.length).toBe(1);
+        expect(favorites[0].id).toBe('track1');
+
+        const removed = await db.toggleFavorite('track', track);
+        expect(removed).toBe(false);
+        const favoritesAfter = await db.getFavorites('track');
+        expect(favoritesAfter.length).toBe(0);
+    });
+
+    test('addToHistory manages recent tracks and avoids duplicates', async () => {
+        const track1 = { id: 't1', title: 'Track 1' };
+        const track2 = { id: 't2', title: 'Track 2' };
+
+        await db.addToHistory(track1);
+        await db.addToHistory(track2);
+        await db.addToHistory(track1);
+
+        const history = await db.getHistory();
+        expect(history.length).toBe(2);
+        expect(history[0].id).toBe('t1');
+        expect(history[1].id).toBe('t2');
+    });
+
+    test('playlist operations: create, add, remove, delete', async () => {
+        const track = { id: 'track1', title: 'Test Track' };
+
+        const playlist = await db.createPlaylist('My Playlist', [track]);
+        expect(playlist.name).toBe('My Playlist');
+        expect(playlist.tracks.length).toBe(1);
+
+        const track2 = { id: 'track2', title: 'Track 2' };
+        await db.addTrackToPlaylist(playlist.id, track2);
+
+        const updated = await db.getPlaylist(playlist.id);
+        expect(updated.tracks.length).toBe(2);
+        expect(updated.tracks[1].id).toBe('track2');
+
+        await db.removeTrackFromPlaylist(playlist.id, 'track1');
+        const afterRemove = await db.getPlaylist(playlist.id);
+        expect(afterRemove.tracks.length).toBe(1);
+        expect(afterRemove.tracks[0].id).toBe('track2');
+
+        await db.deletePlaylist(playlist.id);
+        const deleted = await db.getPlaylist(playlist.id);
+        expect(deleted).toBeUndefined();
+    });
+
+    test('pinned items management', async () => {
+        const album = { id: 'album1', title: 'Album 1', type: 'album' };
+
+        await db.togglePinned(album, 'album');
+        let pinned = await db.getPinned();
+        expect(pinned.length).toBe(1);
+        expect(pinned[0].id).toBe('album1');
+
+        await db.togglePinned({ id: 'a2', title: 'A2' }, 'album');
+        await db.togglePinned({ id: 'a3', title: 'A3' }, 'album');
+        await db.togglePinned({ id: 'a4', title: 'A4' }, 'album');
+
+        pinned = await db.getPinned();
+        expect(pinned.length).toBe(3);
+        expect(pinned.some((p) => p.id === 'a4')).toBe(true);
+        expect(pinned.some((p) => p.id === 'album1')).toBe(false);
+    });
+});
diff --git a/js/tests/player.test.js b/js/tests/player.test.js
new file mode 100644
index 0000000..07821a9
--- /dev/null
+++ b/js/tests/player.test.js
@@ -0,0 +1,195 @@
+import { expect, test, describe, beforeEach, vi, afterEach } from 'vitest';
+import { Player } from '../player.js';
+import { REPEAT_MODE } from '../utils.js';
+import { audioEffectsSettings } from '../storage.js';
+
+vi.mock('../audio-context.js', () => ({
+    audioContextManager: {
+        init: vi.fn(),
+        resume: vi.fn(() => Promise.resolve()),
+        isReady: vi.fn(() => false),
+        setVolume: vi.fn(),
+        changeSource: vi.fn(),
+    },
+}));
+
+vi.mock('../storage.js', () => ({
+    queueManager: {
+        getQueue: vi.fn(() => null),
+        saveQueue: vi.fn(),
+    },
+    replayGainSettings: { getMode: vi.fn(() => 'off'), getPreamp: vi.fn(() => 0) },
+    trackDateSettings: { useAlbumYear: vi.fn(() => true) },
+    exponentialVolumeSettings: { applyCurve: vi.fn((v) => v) },
+    audioEffectsSettings: {
+        getSpeed: vi.fn(() => 1.0),
+        setSpeed: vi.fn(),
+        isPreservePitchEnabled: vi.fn(() => true),
+        setPreservePitch: vi.fn(),
+    },
+    radioSettings: { isEnabled: vi.fn(() => false) },
+    contentBlockingSettings: {
+        shouldHideTrack: vi.fn(() => false),
+        shouldHideAlbum: vi.fn(() => false),
+        shouldHideArtist: vi.fn(() => false),
+    },
+    qualityBadgeSettings: { isEnabled: vi.fn(() => true) },
+    coverArtSizeSettings: { getSize: vi.fn(() => '1280') },
+    apiSettings: {
+        loadInstancesFromGitHub: vi.fn(() => Promise.resolve([])),
+        getInstances: vi.fn(() => Promise.resolve([])),
+    },
+    recentActivityManager: { addArtist: vi.fn(), addAlbum: vi.fn() },
+    themeManager: { getTheme: vi.fn(() => 'dark'), setTheme: vi.fn() },
+    lastFMStorage: { isEnabled: vi.fn(() => false) },
+    nowPlayingSettings: { getMode: vi.fn(() => 'cover') },
+    gaplessPlaybackSettings: { isEnabled: vi.fn(() => true) },
+}));
+
+vi.mock('../db.js', () => ({
+    db: {
+        get: vi.fn(),
+        put: vi.fn(),
+    },
+}));
+
+vi.mock('../ui.js', () => ({
+    UIRenderer: {
+        renderQueue: vi.fn(),
+    },
+}));
+
+vi.mock('shaka-player', () => ({
+    default: {
+        polyfill: { installAll: vi.fn() },
+        Player: {
+            isBrowserSupported: vi.fn(() => true),
+            prototype: {
+                configure: vi.fn(),
+                addEventListener: vi.fn(),
+                load: vi.fn(),
+                unload: vi.fn(),
+            },
+        },
+    },
+    polyfill: { installAll: vi.fn() },
+    Player: class {
+        static isBrowserSupported() {
+            return true;
+        }
+        configure() {}
+        addEventListener() {}
+        load() {
+            return Promise.resolve();
+        }
+        unload() {
+            return Promise.resolve();
+        }
+        destroy() {
+            return Promise.resolve();
+        }
+    },
+}));
+
+describe('Player', () => {
+    let audioElement;
+    let api;
+    let player;
+
+    beforeEach(async () => {
+        document.body.innerHTML = `
+            <audio id="audio-player"></audio>
+            <video id="video-player"></video>
+            <div class="now-playing-bar">
+                <img class="cover" src="">
+                <div class="title"></div>
+                <div class="artist"></div>
+                <div class="album"></div>
+            </div>
+            <div id="total-duration"></div>
+        `;
+
+        audioElement = document.getElementById('audio-player');
+        api = {
+            getCoverUrl: vi.fn((id) => `url-${id}`),
+            getCoverSrcset: vi.fn(),
+            getStreamUrl: vi.fn(),
+        };
+
+        Player._instance = null;
+    });
+
+    afterEach(() => {
+        vi.clearAllMocks();
+    });
+
+    test('initialization sets up initial state', async () => {
+        player = new Player(audioElement, api);
+        expect(player.audio).toBe(audioElement);
+        expect(player.api).toBe(api);
+        expect(player.queue).toEqual([]);
+        expect(player.shuffleActive).toBe(false);
+    });
+
+    test('setVolume updates userVolume and localStorage', () => {
+        player = new Player(audioElement, api);
+        player.setVolume(0.5);
+        expect(player.userVolume).toBe(0.5);
+        expect(localStorage.getItem('volume')).toBe('0.5');
+    });
+
+    test('shuffle toggles correctly', () => {
+        player = new Player(audioElement, api);
+        player.queue = [{ id: 1 }, { id: 2 }, { id: 3 }];
+
+        player.toggleShuffle();
+        expect(player.shuffleActive).toBe(true);
+        expect(player.shuffledQueue.length).toBe(3);
+
+        player.toggleShuffle();
+        expect(player.shuffleActive).toBe(false);
+    });
+
+    test('repeat mode cycles correctly', () => {
+        player = new Player(audioElement, api);
+        expect(player.repeatMode).toBe(REPEAT_MODE.OFF);
+
+        player.toggleRepeat();
+        expect(player.repeatMode).toBe(REPEAT_MODE.ALL);
+
+        player.toggleRepeat();
+        expect(player.repeatMode).toBe(REPEAT_MODE.ONE);
+
+        player.toggleRepeat();
+        expect(player.repeatMode).toBe(REPEAT_MODE.OFF);
+    });
+
+    test('addToQueue adds tracks to the end', async () => {
+        player = new Player(audioElement, api);
+        player.queue = [{ id: 1 }];
+
+        await player.addToQueue([{ id: 2 }, { id: 3 }]);
+        expect(player.queue.length).toBe(3);
+        expect(player.queue[2].id).toBe(3);
+    });
+
+    test('clearQueue resets queue state', async () => {
+        player = new Player(audioElement, api);
+        player.queue = [{ id: 1 }];
+        player.currentQueueIndex = 0;
+
+        await player.clearQueue();
+        expect(player.queue).toEqual([]);
+        expect(player.currentQueueIndex).toBe(-1);
+    });
+
+    test('setPlaybackSpeed clamps values', () => {
+        player = new Player(audioElement, api);
+
+        player.setPlaybackSpeed(2.0);
+        expect(audioEffectsSettings.setSpeed).toHaveBeenCalledWith(2.0);
+
+        player.setPlaybackSpeed(0);
+        expect(audioEffectsSettings.setSpeed).toHaveBeenCalledWith(0.01);
+    });
+});
diff --git a/js/tests/storage.test.js b/js/tests/storage.test.js
new file mode 100644
index 0000000..3162623
--- /dev/null
+++ b/js/tests/storage.test.js
@@ -0,0 +1,125 @@
+import { expect, test, describe, beforeEach, vi } from 'vitest';
+import {
+    recentActivityManager,
+    themeManager,
+    lastFMStorage,
+    nowPlayingSettings,
+    gaplessPlaybackSettings,
+    exponentialVolumeSettings,
+    audioEffectsSettings,
+} from '../storage.js';
+
+describe('storage.js', () => {
+    beforeEach(() => {
+        localStorage.clear();
+        vi.clearAllMocks();
+    });
+
+    describe('recentActivityManager', () => {
+        test('initializes with empty arrays', () => {
+            const recents = recentActivityManager.getRecents();
+            expect(recents.artists).toEqual([]);
+            expect(recents.albums).toEqual([]);
+        });
+
+        test('adds artist and maintains limit', () => {
+            for (let i = 0; i < 15; i++) {
+                recentActivityManager.addArtist({ id: i, name: `Artist ${i}` });
+            }
+            const recents = recentActivityManager.getRecents();
+            expect(recents.artists.length).toBe(10);
+            expect(recents.artists[0].id).toBe(14);
+        });
+
+        test('clears recents', () => {
+            recentActivityManager.addArtist({ id: 1, name: 'Artist' });
+            recentActivityManager.clear();
+            const recents = recentActivityManager.getRecents();
+            expect(recents.artists).toEqual([]);
+        });
+    });
+
+    describe('themeManager', () => {
+        test('gets and sets theme', () => {
+            themeManager.setTheme('dark');
+            expect(themeManager.getTheme()).toBe('dark');
+            expect(document.documentElement.getAttribute('data-theme')).toBe('dark');
+        });
+
+        test('handles custom theme', () => {
+            const colors = { primary: '#ff0000', background: '#000000' };
+            themeManager.setCustomTheme(colors);
+            expect(themeManager.getTheme()).toBe('custom');
+            expect(themeManager.getCustomTheme()).toEqual(colors);
+            expect(document.documentElement.style.getPropertyValue('--primary')).toBe('#ff0000');
+        });
+    });
+
+    describe('lastFMStorage', () => {
+        test('handles enabled state', () => {
+            lastFMStorage.setEnabled(true);
+            expect(lastFMStorage.isEnabled()).toBe(true);
+            lastFMStorage.setEnabled(false);
+            expect(lastFMStorage.isEnabled()).toBe(false);
+        });
+
+        test('obfuscates sensitive data', () => {
+            const key = 'test-api-key';
+            lastFMStorage.setCustomApiKey(key);
+            expect(localStorage.getItem(lastFMStorage.CUSTOM_API_KEY)).not.toBe(key);
+            expect(lastFMStorage.getCustomApiKey()).toBe(key);
+        });
+    });
+
+    describe('nowPlayingSettings', () => {
+        test('gets and sets mode', () => {
+            expect(nowPlayingSettings.getMode()).toBe('cover');
+            nowPlayingSettings.setMode('visualizer');
+            expect(nowPlayingSettings.getMode()).toBe('visualizer');
+        });
+    });
+
+    describe('gaplessPlaybackSettings', () => {
+        test('defaults to true', () => {
+            expect(gaplessPlaybackSettings.isEnabled()).toBe(true);
+        });
+
+        test('sets enabled state', () => {
+            gaplessPlaybackSettings.setEnabled(false);
+            expect(gaplessPlaybackSettings.isEnabled()).toBe(false);
+        });
+    });
+
+    describe('exponentialVolumeSettings', () => {
+        test('applies curve when enabled', () => {
+            exponentialVolumeSettings.setEnabled(true);
+            expect(exponentialVolumeSettings.applyCurve(0.5)).toBeCloseTo(0.125);
+            expect(exponentialVolumeSettings.inverseCurve(0.125)).toBeCloseTo(0.5);
+        });
+
+        test('does not apply curve when disabled', () => {
+            exponentialVolumeSettings.setEnabled(false);
+            expect(exponentialVolumeSettings.applyCurve(0.5)).toBe(0.5);
+            expect(exponentialVolumeSettings.inverseCurve(0.5)).toBe(0.5);
+        });
+    });
+
+    describe('audioEffectsSettings', () => {
+        test('gets and sets speed within bounds', () => {
+            audioEffectsSettings.setSpeed(2.0);
+            expect(audioEffectsSettings.getSpeed()).toBe(2.0);
+
+            audioEffectsSettings.setSpeed(200);
+            expect(audioEffectsSettings.getSpeed()).toBe(100);
+
+            audioEffectsSettings.setSpeed(0);
+            expect(audioEffectsSettings.getSpeed()).toBe(0.01);
+        });
+
+        test('resets speed', () => {
+            audioEffectsSettings.setSpeed(2.0);
+            audioEffectsSettings.resetSpeed();
+            expect(audioEffectsSettings.getSpeed()).toBe(1.0);
+        });
+    });
+});
diff --git a/js/tests/utils.test.js b/js/tests/utils.test.js
new file mode 100644
index 0000000..edacfbc
--- /dev/null
+++ b/js/tests/utils.test.js
@@ -0,0 +1,211 @@
+import { expect, test, describe, vi } from 'vitest';
+import * as utils from '../utils.js';
+
+vi.mock('../ModernSettings.js', () => ({
+    modernSettings: {
+        filenameTemplate: '{artist} - {album} - {trackNumber} - {title}',
+    },
+}));
+
+vi.mock('../icons.js', () => ({
+    SVG_ATMOS: () => '<svg>atmos</svg>',
+}));
+
+vi.mock('../storage.js', () => ({
+    qualityBadgeSettings: { isEnabled: vi.fn(() => true) },
+    coverArtSizeSettings: { getSize: vi.fn(() => '1280') },
+    trackDateSettings: { useAlbumYear: vi.fn(() => false) },
+}));
+
+describe('utils.js', () => {
+    describe('formatTime', () => {
+        test('formats seconds into M:SS', () => {
+            expect(utils.formatTime(0)).toBe('0:00');
+            expect(utils.formatTime(5)).toBe('0:05');
+            expect(utils.formatTime(60)).toBe('1:00');
+            expect(utils.formatTime(65)).toBe('1:05');
+        });
+
+        test('formats seconds into H:MM:SS', () => {
+            expect(utils.formatTime(3600)).toBe('1:00:00');
+            expect(utils.formatTime(3665)).toBe('1:01:05');
+        });
+
+        test('handles NaN', () => {
+            expect(utils.formatTime(NaN)).toBe('0:00');
+        });
+    });
+
+    describe('sanitizeForFilename', () => {
+        test('replaces invalid characters with underscores', () => {
+            expect(utils.sanitizeForFilename('a/b:c*d?e"f<g>h|i')).toBe('a_b_c_d_e_f_g_h_i');
+        });
+
+        test('collapses multiple spaces and trims', () => {
+            expect(utils.sanitizeForFilename('  hello   world  ')).toBe('hello world');
+        });
+
+        test('returns "Unknown" for empty input', () => {
+            expect(utils.sanitizeForFilename('')).toBe('Unknown');
+            expect(utils.sanitizeForFilename(null)).toBe('Unknown');
+        });
+    });
+
+    describe('replaceTokens', () => {
+        test('replaces tokens in template', () => {
+            const template = '{artist} - {title}';
+            const tokens = { artist: 'Artist', title: 'Title' };
+            expect(utils.replaceTokens(template, tokens)).toBe('Artist - Title');
+        });
+
+        test('leaves unknown tokens as is', () => {
+            const template = '{artist} - {unknown}';
+            const tokens = { artist: 'Artist' };
+            expect(utils.replaceTokens(template, tokens)).toBe('Artist - {unknown}');
+        });
+    });
+
+    describe('formatPathTemplate', () => {
+        test('formats path correctly', () => {
+            const data = {
+                artist: 'Artist',
+                album: 'Album',
+                trackNumber: 1,
+                title: 'Title',
+                discNumber: 1,
+            };
+            const template = '{artist}/{album}/{trackNumber} - {title}';
+            expect(utils.formatPathTemplate(template, data)).toBe('Artist/Album/01 - Title');
+        });
+
+        test('strips . and .. segments', () => {
+            const data = { artist: '..', title: '.' };
+            const template = '{artist}/{title}/song';
+            expect(utils.formatPathTemplate(template, data)).toBe('song');
+        });
+    });
+
+    describe('detectAudioFormat', () => {
+        test('detects flac', () => {
+            const view = new DataView(new Uint8Array([0x66, 0x4c, 0x61, 0x43]).buffer);
+            expect(utils.detectAudioFormat(view)).toBe('flac');
+        });
+
+        test('detects mp4', () => {
+            const view = new DataView(new Uint8Array([0, 0, 0, 0, 0x66, 0x74, 0x79, 0x70]).buffer);
+            expect(utils.detectAudioFormat(view)).toBe('mp4');
+        });
+
+        test('detects mp3 (ID3)', () => {
+            const view = new DataView(new Uint8Array([0x49, 0x44, 0x33]).buffer);
+            expect(utils.detectAudioFormat(view)).toBe('mp3');
+        });
+
+        test('detects ogg', () => {
+            const view = new DataView(new Uint8Array([0x4f, 0x67, 0x67, 0x53]).buffer);
+            expect(utils.detectAudioFormat(view)).toBe('ogg');
+        });
+
+        test('returns null for unknown format', () => {
+            const view = new DataView(new Uint8Array([0, 0, 0, 0]).buffer);
+            expect(utils.detectAudioFormat(view)).toBeNull();
+        });
+    });
+
+    describe('normalizeQualityToken', () => {
+        test('normalizes various quality strings', () => {
+            expect(utils.normalizeQualityToken('HI_RES_LOSSLESS')).toBe('HI_RES_LOSSLESS');
+            expect(utils.normalizeQualityToken('MASTER')).toBe('HI_RES_LOSSLESS');
+            expect(utils.normalizeQualityToken('HIFI')).toBe('LOSSLESS');
+            expect(utils.normalizeQualityToken('ATMOS')).toBe('DOLBY_ATMOS');
+        });
+
+        test('returns null for unknown quality', () => {
+            expect(utils.normalizeQualityToken('UNKNOWN')).toBeNull();
+        });
+    });
+
+    describe('pickBestQuality', () => {
+        test('picks the highest quality from list', () => {
+            expect(utils.pickBestQuality(['LOSSLESS', 'HI_RES_LOSSLESS', 'HIGH'])).toBe('HI_RES_LOSSLESS');
+            expect(utils.pickBestQuality(['LOW', 'HIGH'])).toBe('HIGH');
+            expect(utils.pickBestQuality(['DOLBY_ATMOS', 'HI_RES_LOSSLESS'])).toBe('DOLBY_ATMOS');
+        });
+    });
+
+    describe('getTrackTitle', () => {
+        test('returns title with version if present', () => {
+            expect(utils.getTrackTitle({ title: 'Song', version: 'Remix' })).toBe('Song (Remix)');
+        });
+
+        test('returns just title if no version', () => {
+            expect(utils.getTrackTitle({ title: 'Song' })).toBe('Song');
+        });
+
+        test('returns fallback if no title', () => {
+            expect(utils.getTrackTitle({}, { fallback: 'No Title' })).toBe('No Title');
+        });
+    });
+
+    describe('getTrackArtists', () => {
+        test('joins multiple artists', () => {
+            const track = { artists: [{ name: 'A' }, { name: 'B' }] };
+            expect(utils.getTrackArtists(track)).toBe('A, B');
+        });
+
+        test('returns fallback if no artists', () => {
+            expect(utils.getTrackArtists({})).toBe('Unknown Artist');
+        });
+    });
+
+    describe('getTrackDiscNumber', () => {
+        test('extracts disc number from various properties', () => {
+            expect(utils.getTrackDiscNumber({ discNumber: 2 })).toBe(2);
+            expect(utils.getTrackDiscNumber({ volumeNumber: 3 })).toBe(3);
+            expect(utils.getTrackDiscNumber({ mediaNumber: 4 })).toBe(4);
+        });
+
+        test('returns null for invalid values', () => {
+            expect(utils.getTrackDiscNumber({ discNumber: 0 })).toBeNull();
+            expect(utils.getTrackDiscNumber({ discNumber: 'abc' })).toBeNull();
+        });
+    });
+
+    describe('tryCatch', () => {
+        test('executes sync function', () => {
+            const fn = vi.fn(() => 'success');
+            const onError = vi.fn();
+            expect(utils.tryCatch(fn, onError)).toBe('success');
+            expect(onError).not.toHaveBeenCalled();
+        });
+
+        test('handles sync error', () => {
+            const error = new Error('fail');
+            const fn = vi.fn(() => {
+                throw error;
+            });
+            const onError = vi.fn((err) => err.message);
+            expect(utils.tryCatch(fn, onError)).toBe('fail');
+            expect(onError).toHaveBeenCalledWith(error);
+        });
+
+        test('executes async function', async () => {
+            const fn = vi.fn(async () => 'success');
+            const onError = vi.fn();
+            const result = await utils.tryCatch(fn, onError);
+            expect(result).toBe('success');
+            expect(onError).not.toHaveBeenCalled();
+        });
+
+        test('handles async error', async () => {
+            const error = new Error('fail');
+            const fn = vi.fn(async () => {
+                throw error;
+            });
+            const onError = vi.fn(async (err) => err.message);
+            const result = await utils.tryCatch(fn, onError);
+            expect(result).toBe('fail');
+            expect(onError).toHaveBeenCalledWith(error);
+        });
+    });
+});