Function isSubpath

packages/python-analysis/src/util/fs.ts:61–64

(somePath: Path, parentPath: Path)

 * isSubpath('/a/x', '/a/b')   // false - x is not under b
 */
export function isSubpath(somePath: Path, parentPath: Path): boolean {
  const rel = path.relative(parentPath, somePath);
  return rel === '' || (!rel.startsWith('..') && !path.isAbsolute(rel));
}