Function getPrecedingDocstring

src/extraction/tree-sitter-helpers.ts:95–127

(node: SyntaxNode, source: string)

 * Get the docstring/comment preceding a node
 */
export function getPrecedingDocstring(node: SyntaxNode, source: string): string | undefined {
  // Climb out of any wrapper(s) so a comment preceding the WHOLE construct
  // (export-, decorator-, or const-arrow-wrapped) is reachable as a sibling.
  // The emitted node's own `previousNamedSibling` is empty (export/const) or a
  // decorator (Python) in those cases, so without this the docstring was
  // dropped. (#780)
  let anchor = node;
  while (anchor.parent && DOCSTRING_WRAPPER_TYPES.has(anchor.parent.type)) {
    anchor = anchor.parent;
  }

  let sibling = anchor.previousNamedSibling;
  const comments: string[] = [];

  while (sibling) {
    if (
      sibling.type === 'comment' ||
      sibling.type === 'line_comment' ||
      sibling.type === 'block_comment' ||
      sibling.type === 'documentation_comment'
    ) {
      comments.unshift(getNodeText(sibling, source));
      sibling = sibling.previousNamedSibling;
    } else {
      break;
    }
  }

  if (comments.length === 0) return undefined;

  // Strip each comment's syntax markers (language-aware), then join.
  return comments.map(cleanCommentMarkers).join('\n').trim();
}