fix(client): log unhandled WebSocket event names instead of empty list

An <updates> frame whose only child is an element the WebSocketEvent
struct doesn't model (e.g. nowSelectionUpdated, sent by SoundTouch 10
firmware around a play action) produced no known event types, so
handleEvent logged "Received unknown event types: []" repeatedly. The
empty list carried no information and flooded soundtouch-web's logs and
the CLI events subscribe output we point people at for debugging.

Capture unmodeled <updates> children by name via an xml:",any" catch-all
on WebSocketEvent and log the actual element names ("[nowSelectionUpdated]"),
skipping frames that carry no child events entirely. A regression test
confirms a modeled event is not also captured as unknown.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

pkg/client/websocket.go

@@ -563,7 +563,11 @@ func (ws *WebSocketClient) handleEvent(event *models.WebSocketEvent) {
 	if !hasKnownEvent && handlers.OnUnknownEvent != nil {
 		handlers.OnUnknownEvent(event)
 	} else if !hasKnownEvent {
-		ws.logger.Printf("Received unknown event types: %v", eventTypes)
+		// Log the actual unmodeled element names (e.g. nowSelectionUpdated)
+		// rather than an empty list; skip frames that carry no child events.
+		if names := event.UnknownEventNames(); len(names) > 0 {
+			ws.logger.Printf("Received unhandled event types: %v", names)
+		}
 	}
 }
 

pkg/models/websocket.go

@@ -102,7 +102,28 @@ type WebSocketEvent struct {
 	ErrorUpdated           *ErrorUpdatedEvent           `xml:"errorUpdated,omitempty"`
 	RecentsUpdated         *RecentsUpdatedEvent         `xml:"recentsUpdated,omitempty"`
 	LanguageUpdated        *LanguageUpdatedEvent        `xml:"languageUpdated,omitempty"`
-	Timestamp              time.Time                    `json:"timestamp"` // Added by client for tracking
+	// UnknownElements captures <updates> children we don't model yet (e.g.
+	// nowSelectionUpdated), so callers can log them by name instead of an
+	// empty list when no known event matched.
+	UnknownElements []UnknownElement `xml:",any"`
+	Timestamp       time.Time        `json:"timestamp"` // Added by client for tracking
+}
+
+// UnknownElement records the tag name of an <updates> child element that the
+// WebSocketEvent struct does not (yet) model.
+type UnknownElement struct {
+	XMLName xml.Name
+}
+
+// UnknownEventNames returns the tag names of any unmodeled <updates> children,
+// for diagnostic logging.
+func (e *WebSocketEvent) UnknownEventNames() []string {
+	names := make([]string, 0, len(e.UnknownElements))
+	for _, u := range e.UnknownElements {
+		names = append(names, u.XMLName.Local)
+	}
+
+	return names
 }
 
 // GetEvents returns all events present in this WebSocket event

pkg/models/websocket_test.go

@@ -540,3 +540,41 @@ func TestCreateMockWebSocketEvent(t *testing.T) {
 		t.Errorf("Event types don't match expected values")
 	}
 }
+
+// TestParseWebSocketEvent_UnknownElements verifies that an <updates> envelope
+// whose only child is an unmodeled element (e.g. nowSelectionUpdated, observed
+// on real SoundTouch 10 firmware) parses with no known event types but with
+// the element captured by name, so callers can log something useful instead
+// of an empty list.
+func TestParseWebSocketEvent_UnknownElements(t *testing.T) {
+	raw := []byte(`<updates deviceID="A81B6A536A98"><nowSelectionUpdated><preset id="0"><ContentItem source="TUNEIN" type="stationurl" location="/v1/playback/station/s308770" sourceAccount="" isPresetable="true"><itemName>Willy</itemName></ContentItem></preset></nowSelectionUpdated></updates>`)
+
+	event, err := ParseWebSocketEvent(raw)
+	if err != nil {
+		t.Fatalf("ParseWebSocketEvent: %v", err)
+	}
+
+	if got := event.GetEventTypes(); len(got) != 0 {
+		t.Errorf("expected no known event types, got %v", got)
+	}
+
+	names := event.UnknownEventNames()
+	if len(names) != 1 || names[0] != "nowSelectionUpdated" {
+		t.Errorf("expected [nowSelectionUpdated], got %v", names)
+	}
+}
+
+// TestParseWebSocketEvent_KnownEventNoUnknowns confirms a modeled event is not
+// also captured as an unknown element.
+func TestParseWebSocketEvent_KnownEventNoUnknowns(t *testing.T) {
+	raw := []byte(`<updates deviceID="A81B6A536A98"><nowPlayingUpdated><nowPlaying deviceID="A81B6A536A98" source="TUNEIN"></nowPlaying></nowPlayingUpdated></updates>`)
+
+	event, err := ParseWebSocketEvent(raw)
+	if err != nil {
+		t.Fatalf("ParseWebSocketEvent: %v", err)
+	}
+
+	if names := event.UnknownEventNames(); len(names) != 0 {
+		t.Errorf("expected no unknown elements for a modeled event, got %v", names)
+	}
+}