unreferenced method

List<String> unreferenced({ required Set<String> roots, })

Library files that nothing in the project refers to: in-degree zero over edges, with roots exempt.

One layer deep on purpose — a file kept alive only by another dead file is not listed. unreachable is the deeper question.

Implementation

List<String> unreferenced({required Set<String> roots}) {
  final referenced = <String>{};
  for (final targets in edges.values) {
    referenced.addAll(targets);
  }
  return edges.keys
      .where((file) =>
          isLibraryFile(file) &&
          !referenced.contains(file) &&
          !roots.contains(file))
      .toList()
    ..sort();
}