void normalize()

in lib/src/parsed_path.dart [100:144]
33 lines of code
16 McCabe index (conditional complexity)

  void normalize({bool canonicalize = false}) {
    // Handle '.', '..', and empty parts.
    var leadingDoubles = 0;
    final newParts = <String>[];
    for (var part in parts) {
      if (part == '.' || part == '') {
        // Do nothing. Ignore it.
      } else if (part == '..') {
        // Pop the last part off.
        if (newParts.isNotEmpty) {
          newParts.removeLast();
        } else {
          // Backed out past the beginning, so preserve the "..".
          leadingDoubles++;
        }
      } else {
        newParts.add(canonicalize ? style.canonicalizePart(part) : part);
      }
    }

    // A relative path can back out from the start directory.
    if (!isAbsolute) {
      newParts.insertAll(0, List.filled(leadingDoubles, '..'));
    }

    // If we collapsed down to nothing, do ".".
    if (newParts.isEmpty && !isAbsolute) {
      newParts.add('.');
    }

    // Canonicalize separators.
    parts = newParts;
    separators =
        List.filled(newParts.length + 1, style.separator, growable: true);
    if (!isAbsolute || newParts.isEmpty || !style.needsSeparator(root!)) {
      separators[0] = '';
    }

    // Normalize the Windows root if needed.
    if (root != null && style == Style.windows) {
      if (canonicalize) root = root!.toLowerCase();
      root = root!.replaceAll('/', '\\');
    }
    removeTrailingSeparators();
  }