anthropic: Add improved handling of other error event types

llms/anthropic/anthropicllm.go

@@ -152,6 +152,9 @@ func generateMessagesContent(ctx context.Context, o *LLM, messages []llms.Messag
 		}
 		return nil, fmt.Errorf("anthropic: failed to create message: %w", err)
 	}
+	if result == nil {
+		return nil, ErrEmptyResponse
+	}
 
 	choices := make([]*llms.ContentChoice, len(result.Content))
 	for i, content := range result.Content {

llms/anthropic/internal/anthropicclient/messages.go

@@ -135,7 +135,7 @@ func (m *MessageResponsePayload) UnmarshalJSON(data []byte) error {
 			}
 			m.Content = append(m.Content, tuc)
 		default:
-			return fmt.Errorf("unknown content type: %s", typeStruct.Type)
+			return fmt.Errorf("unknown content type: %s\n%v", typeStruct.Type, string(raw))
 		}
 	}
 
@@ -268,8 +268,10 @@ func processStreamEvent(ctx context.Context, event map[string]interface{}, paylo
 		eventChan <- MessageEvent{Response: &response, Err: nil}
 	case "ping":
 		// Nothing to do here
+	case "error":
+		eventChan <- MessageEvent{Response: nil, Err: fmt.Errorf("received error event: %v", event)}
 	default:
-		log.Printf("unknown event type: %s", eventType)
+		log.Printf("unknown event type: %s - %v", eventType, event)
 	}
 	return response, nil
 }