Function getRoot

packages/typescript/src/index.ts:119–122

(p: string)

      // Different roots (e.g., drive letters on Windows) cannot be in a parent/child relationship.
      // Normalize Windows drive-letter case before comparison to avoid false mismatches.
      const getRoot = (p: string) => {
        const r = path.parse(p).root;
        return process.platform === 'win32' ? r.toLowerCase() : r;
      };
      if (getRoot(effectiveOutDir) !== getRoot(baseForContainment)) return false;
      const rel = path.relative(effectiveOutDir, baseForContainment);
      // rel === '' -> same dir; absolute or '..' => outside