Stream list()

in lib/src/list_tree.dart [316:374]
49 lines of code
10 McCabe index (conditional complexity)

  Stream<FileSystemEntity> list(String dir, FileSystem fileSystem,
      {bool followLinks = true}) {
    if (isRecursive) {
      return fileSystem
          .directory(dir)
          .list(recursive: true, followLinks: followLinks)
          .where((entity) => _matches(p.relative(entity.path, from: dir)));
    }

    // Don't spawn extra [Directory.list] calls when we already know exactly
    // which subdirectories we're interested in.
    if (_isIntermediate && _caseSensitive) {
      var resultGroup = StreamGroup<FileSystemEntity>();
      children!.forEach((sequence, child) {
        resultGroup.add(child.list(
            p.join(dir, (sequence.nodes.single as LiteralNode).text),
            fileSystem,
            followLinks: followLinks));
      });
      resultGroup.close();
      return resultGroup.stream;
    }

    return StreamCompleter.fromFuture(() async {
      var entities = await fileSystem
          .directory(dir)
          .list(followLinks: followLinks)
          .toList();
      await _validateIntermediateChildrenAsync(dir, entities, fileSystem);

      var resultGroup = StreamGroup<FileSystemEntity>();
      var resultController = StreamController<FileSystemEntity>(sync: true);
      unawaited(resultGroup.add(resultController.stream));
      for (var entity in entities) {
        var basename = p.relative(entity.path, from: dir);
        if (_matches(basename)) resultController.add(entity);

        children!.forEach((sequence, child) {
          if (entity is! Directory) return;
          if (!sequence.matches(basename)) return;
          var stream = child
              .list(p.join(dir, basename), fileSystem, followLinks: followLinks)
              .handleError((_) {}, test: (error) {
            // Ignore errors from directories not existing. We do this here so
            // that we only ignore warnings below wild cards. For example, the
            // glob "foo/bar/*/baz" should fail if "foo/bar" doesn't exist but
            // succeed if "foo/bar/qux/baz" doesn't exist.
            return error is FileSystemException &&
                (error.osError!.errorCode == _enoent ||
                    error.osError!.errorCode == _enoentWin);
          });
          resultGroup.add(stream);
        });
      }
      unawaited(resultController.close());
      unawaited(resultGroup.close());
      return resultGroup.stream;
    }());
  }