Function getTraceData

packages/core/src/utils/traceData.ts:35–85

(
  options: { span?: Span; scope?: Scope; client?: Client; propagateTraceparent?: boolean } = {},
)

 * or meta tag name.
 */
export function getTraceData(
  options: { span?: Span; scope?: Scope; client?: Client; propagateTraceparent?: boolean } = {},
): SerializedTraceData {
  const client = options.client || getClient();
  if (!isEnabled() || !client) {
    return {};
  }

  const carrier = getMainCarrier();
  const acs = getAsyncContextStrategy(carrier);
  if (acs.getTraceData) {
    return acs.getTraceData(options);
  }

  const scope = options.scope || getCurrentScope();
  const span = options.span || getActiveSpan();

  // In Tracing-without-Performance (TwP) mode, spans are non-recording placeholders that carry no
  // sampling decision of their own (it's deferred). The scope is the source of truth, so we read
  // the trace headers from the scope. A non-recording span in *tracing* mode (e.g. an unsampled
  // child or an ignored span) is different: it represents an explicit negative decision, which
  // `spanToTraceHeader` correctly encodes as `-0`, so we keep reading those from the span.
  const isTwpPlaceholder = spanIsNonRecordingSpan(span) && !hasSpansEnabled(client.getOptions());

  // When there's no recording span and an external propagation context is registered (e.g. OTLP
  // integration), return empty to let the external propagator handle outgoing request propagation.
  if (!span && hasExternalPropagationContext()) {
    return {};
  }

  const sentryTrace = span && !isTwpPlaceholder ? spanToTraceHeader(span) : scopeToTraceHeader(scope);
  const dsc = span ? getDynamicSamplingContextFromSpan(span) : getDynamicSamplingContextFromScope(client, scope);
  const baggage = dynamicSamplingContextToSentryBaggageHeader(dsc);

  const isValidSentryTraceHeader = TRACEPARENT_REGEXP.test(sentryTrace);
  if (!isValidSentryTraceHeader) {
    debug.warn('Invalid sentry-trace data. Cannot generate trace data');
    return {};
  }

  const traceData: SerializedTraceData = {
    'sentry-trace': sentryTrace,
    baggage,
  };

  if (options.propagateTraceparent) {
    traceData.traceparent = span && !isTwpPlaceholder ? spanToTraceparentHeader(span) : scopeToTraceparentHeader(scope);
  }

  return traceData;
}

/**
 * Get a sentry-trace header value for the given scope.