Function startNewTrace

packages/core/src/tracing/trace.ts:321–335

(callback: () => T)

 *            or page will automatically create a new trace.
 */
export function startNewTrace<T>(callback: () => T): T {
  const acs = getAcs();
  if (acs.startNewTrace) {
    return acs.startNewTrace(callback);
  }

  return withScope(scope => {
    scope.setPropagationContext({
      traceId: generateTraceId(),
      sampleRand: safeMathRandom(),
    });
    DEBUG_BUILD && debug.log(`Starting a new trace with id ${scope.getPropagationContext().traceId}`);
    return withActiveSpan(null, callback);
  });
}

/**
 * The placeholder returned from `startSpan*` when `onlyIfParent` is set but there is no parent span.