Function findFirstMatchingNode

packages/language-service/src/utils/ts_utils.ts:61–83

(
  root: ts.Node,
  opts: FindOptions<T>,
)

 * Finds TypeScript nodes descending from the provided root which match the given filter.
 */
export function findFirstMatchingNode<T extends ts.Node>(
  root: ts.Node,
  opts: FindOptions<T>,
): T | null {
  let match: T | null = null;
  const explore = (currNode: ts.Node) => {
    if (match !== null) {
      return;
    }
    if (opts.position !== undefined) {
      if (currNode.getStart() > opts.position || opts.position >= currNode.getEnd()) {
        return;
      }
    }
    if (opts.filter(currNode)) {
      match = currNode;
      return;
    }
    currNode.forEachChild((descendent) => explore(descendent));
  };
  explore(root);
  return match;
}

/**
 * Resolves a ClassDeclaration from a SymbolReference.