SourceEdit _removeFromBlockList()

in lib/src/list_mutations.dart [209:277]

• 39 lines of code
• 11 McCabe index (conditional complexity)

SourceEdit _removeFromBlockList(
    YamlEditor yamlEdit, YamlList list, YamlNode nodeToRemove, int index) {
  RangeError.checkValueInInterval(index, 0, list.length - 1);

  var end = getContentSensitiveEnd(nodeToRemove);

  /// If we are removing the last element in a block list, convert it into a
  /// flow empty list.
  if (list.length == 1) {
    final start = list.span.start.offset;

    return SourceEdit(start, end - start, '[]');
  }

  final yaml = yamlEdit.toString();
  final span = nodeToRemove.span;

  /// Adjust the end to clear the new line after the end too.
  ///
  /// We do this because we suspect that our users will want the inline
  /// comments to disappear too.
  final nextNewLine = yaml.indexOf('\n', end);
  if (nextNewLine != -1) {
    end = nextNewLine + 1;
  }

  /// If the value is empty
  if (span.length == 0) {
    var start = span.start.offset;
    return SourceEdit(start, end - start, '');
  }

  /// -1 accounts for the fact that the content can start with a dash
  var start = yaml.lastIndexOf('-', span.start.offset - 1);

  /// Check if there is a `-` before the node
  if (start > 0) {
    final lastHyphen = yaml.lastIndexOf('-', start - 1);
    final lastNewLine = yaml.lastIndexOf('\n', start - 1);
    if (lastHyphen > lastNewLine) {
      start = lastHyphen + 2;

      /// If there is a `-` before the node, we need to check if we have
      /// to update the indentation of the next node.
      if (index < list.length - 1) {
        /// Since [end] is currently set to the next new line after the current
        /// node, check if we see a possible comment first, or a hyphen first.
        /// Note that no actual content can appear here.
        ///
        /// We check this way because the start of a span in a block list is
        /// the start of its value, and checking from the back leaves us
        /// easily confused if there are comments that have dashes in them.
        final nextHash = yaml.indexOf('#', end);
        final nextHyphen = yaml.indexOf('-', end);
        final nextNewLine = yaml.indexOf('\n', end);

        /// If [end] is on the same line as the hyphen of the next node
        if ((nextHash == -1 || nextHyphen < nextHash) &&
            nextHyphen < nextNewLine) {
          end = nextHyphen;
        }
      }
    } else if (lastNewLine > lastHyphen) {
      start = lastNewLine + 1;
    }
  }

  return SourceEdit(start, end - start, '');
}