diff --git a/cmd/naviwatcher/main.go b/cmd/naviwatcher/main.go
index 55a8214..41aee35 100644
--- a/cmd/naviwatcher/main.go
+++ b/cmd/naviwatcher/main.go
@@ -49,7 +49,7 @@ func main() {
 		cancel()
 	}()
 
-	app, err := NewApp(ctx, cfg)
+	app, err := NewApp(ctx, cfg, "naviwatcher.db")
 	if err != nil {
 		log.Fatalf("Failed to initialize application: %v", err)
 	}
@@ -63,9 +63,10 @@ func main() {
 }
 
 // NewApp initializes all application components: config, database, and MusicBrainz client.
-func NewApp(ctx context.Context, cfg *config.Config) (*App, error) {
-	// Initialize database (uses default path or could be made configurable).
-	db, err := database.New("naviwatcher.db")
+// dbPath is the SQLite database path (use ":memory:" for tests).
+func NewApp(ctx context.Context, cfg *config.Config, dbPath string) (*App, error) {
+	// Initialize database.
+	db, err := database.New(dbPath)
 	if err != nil {
 		return nil, fmt.Errorf("failed to initialize database: %w", err)
 	}
diff --git a/cmd/naviwatcher/main_test.go b/cmd/naviwatcher/main_test.go
index 0faf8ce..474e479 100644
--- a/cmd/naviwatcher/main_test.go
+++ b/cmd/naviwatcher/main_test.go
@@ -132,7 +132,7 @@ func TestNewApp_CreatesMusicBrainzClient(t *testing.T) {
 	}
 
 	ctx := context.Background()
-	app, err := NewApp(ctx, cfg)
+	app, err := NewApp(ctx, cfg, ":memory:")
 	if err != nil {
 		t.Fatalf("NewApp returned error: %v", err)
 	}
@@ -167,7 +167,7 @@ func TestNewApp_GracefulShutdown(t *testing.T) {
 	}
 
 	ctx := context.Background()
-	app, err := NewApp(ctx, cfg)
+	app, err := NewApp(ctx, cfg, ":memory:")
 	if err != nil {
 		t.Fatalf("NewApp returned error: %v", err)
 	}
@@ -195,7 +195,7 @@ func TestAppRun_GracefulShutdown(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 
-	app, err := NewApp(ctx, cfg)
+	app, err := NewApp(ctx, cfg, ":memory:")
 	if err != nil {
 		t.Fatalf("NewApp returned error: %v", err)
 	}
diff --git a/internal/database/external_releases.go b/internal/database/external_releases.go
index c2388b3..af1f6da 100644
--- a/internal/database/external_releases.go
+++ b/internal/database/external_releases.go
@@ -24,9 +24,9 @@ func FormatCachedAt(t time.Time) interface{} {
 	return t.UTC().Format(utcLayout)
 }
 
-// joinSecondaryTypes renders a slice of secondary types as a comma-separated
+// JoinSecondaryTypes renders a slice of secondary types as a comma-separated
 // string for storage in the secondary_types TEXT column (empty when none).
-func joinSecondaryTypes(types []string) string {
+func JoinSecondaryTypes(types []string) string {
 	return strings.Join(types, ",")
 }
 
@@ -72,7 +72,7 @@ func SaveExternalRelease(db *DB, release *ExternalRelease) error {
 	var cachedAt interface{} = FormatCachedAt(release.CachedAt)
 	_, err := db.Conn().Exec(
 		"INSERT OR REPLACE INTO external_releases (rgid, artist_id, title, type, release_date, is_ignored, cached_at, secondary_types) VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
-		release.RGID, release.ArtistID, release.Title, release.Type, release.ReleaseDate, release.IsIgnored, cachedAt, joinSecondaryTypes(release.SecondaryTypes),
+		release.RGID, release.ArtistID, release.Title, release.Type, release.ReleaseDate, release.IsIgnored, cachedAt, JoinSecondaryTypes(release.SecondaryTypes),
 	)
 	if err != nil {
 		return fmt.Errorf("save external release: %w", err)
diff --git a/internal/musicbrainz/sync.go b/internal/musicbrainz/sync.go
index 6ab7cce..33d5b51 100644
--- a/internal/musicbrainz/sync.go
+++ b/internal/musicbrainz/sync.go
@@ -136,8 +136,8 @@ func SyncArtistDiscography(
 		}
 
 		if _, err := tx.Exec(
-			"INSERT INTO external_releases (rgid, artist_id, title, type, release_date, is_ignored, cached_at) VALUES (?, ?, ?, ?, ?, ?, ?)",
-			ext.RGID, ext.ArtistID, ext.Title, ext.Type, ext.ReleaseDate, ext.IsIgnored, database.FormatCachedAt(ext.CachedAt),
+			"INSERT INTO external_releases (rgid, artist_id, title, type, release_date, is_ignored, cached_at, secondary_types) VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
+			ext.RGID, ext.ArtistID, ext.Title, ext.Type, ext.ReleaseDate, ext.IsIgnored, database.FormatCachedAt(ext.CachedAt), database.JoinSecondaryTypes(ext.SecondaryTypes),
 		); err != nil {
 			return nil, fmt.Errorf("sync artist discography: insert release %s: %w", rg.ID, err)
 		}