onError

interface OverflowErrorEvent<T> {
  elementType: T;
  code: OverflowErrorCode;
  message: string;
  fieldErrors?: FieldError[]; // populated when code === 'validation_failed'
  cause?: unknown;            // diagnostics only, not part of the public contract
}

card.on('onError', ({ code, message, fieldErrors }) => {
  switch (code) {
    case 'validation_failed':
      paintFieldErrors(fieldErrors);
      break;
    case 'tokenization_failed':
      toast(`Card error: ${message}`);
      break;
    case 'network':
      toast('Network error. Try again.');
      break;
    default:
      toast(message);
  }
});

element.on('onError', ({ code, fieldErrors }) => {
  if (code === 'validation_failed') paintFieldErrors(fieldErrors);
});