Function getSpanDescendants

packages/core/src/utils/spanUtils.ts:397–417

(span: SpanWithPotentialChildren)

 * Returns an array of the given span and all of its descendants.
 */
export function getSpanDescendants(span: SpanWithPotentialChildren): Span[] {
  const resultSet = new Set<Span>();

  function addSpanChildren(span: SpanWithPotentialChildren): void {
    // This exit condition is required to not infinitely loop in case of a circular dependency.
    if (resultSet.has(span)) {
      return;
      // We want to ignore unsampled spans (e.g. non recording spans)
    } else if (spanIsSampled(span)) {
      resultSet.add(span);
      const childSpans = span[CHILD_SPANS_FIELD] ? Array.from(span[CHILD_SPANS_FIELD]) : [];
      for (const childSpan of childSpans) {
        addSpanChildren(childSpan);
      }
    }
  }

  addSpanChildren(span);

  return Array.from(resultSet);
}

/**
 * Returns the root span of a given span.