anchor.diff:  /// Returned results will be those files that match file paths or are within
   /// directories defined in the list.
   Future<List<String>> getDartFiles(String directoryPath,
  -    {List<String> searchList, bool followLinks: false}) {
  -  return getFiles(directoryPath,
  -      searchList: searchList,
  -      followLinks: followLinks).where(pathToDartFile).toList();
  -}
  +        {List<String> searchList, bool followLinks: false}) =>
  +    getFiles(directoryPath, searchList: searchList, followLinks: followLinks)
  +        .where(pathToDartFile)
  +        .toList();
   
   /// Skips symbolic links and any item in [directoryPath] recursively that begins
   /// with `.`.
  
positive.code: /// Returned results will be those files that match file paths or are within
  /// directories defined in the list.
  Stream<String> getFiles(String directoryPath,
      {List<String> searchList, bool followLinks: false}) {
    var controller = new StreamController<String>();
    if (searchList == null) {
      searchList = <String>[];
    }
  
    _expandSearchList(directoryPath, searchList).then((map) async {
      var searchDirs = <String>[];
  
      map.forEach((path, type) {
        if (type == FileSystemEntityType.FILE) {
          controller.add(path);
        } else {
          searchDirs.add(path);
        }
      });
  
      await Future.forEach(searchDirs, (path) {
        var rootDir = new Directory(path);
  
        return _populateFiles(rootDir, controller, followLinks: followLinks);
      });
    }).catchError((error, stack) {
      controller.addError(error, stack);
    }).whenComplete(() {
      controller.close();
    });
  
    return controller.stream;
  }
  
  Future<Map<String, FileSystemEntityType>> _expandSearchList(
  
negative.code: 
    var items = <String, FileSystemEntityType>{};
  
    for (var path in searchPaths) {
      var type = await FileSystemEntity.type(path);
  
      if (type != FileSystemEntityType.FILE &&
          type != FileSystemEntityType.DIRECTORY) {
        continue;
      }
  
      /// If there is overlap with the provided paths, just fail.
  