class RuboCop::Cop::MultilineLiteralBraceCorrector

def correct(processed_source, node)
  @processed_source = processed_source
  if closing_brace_on_same_line?(node)
    lambda do |corrector|
      corrector.insert_before(node.loc.end, "\n".freeze)
    end
  else
    # When a comment immediately before the closing brace gets in the
    # way of an easy correction, the offense is reported but not auto-
    # corrected. The user must handle the delicate decision of where to
    # put the comment.
    return if new_line_needed_before_closing_brace?(node)
    lambda do |corrector|
      corrector.remove(range_with_surrounding_space(range: node.loc.end,
                                                    side: :left))
      corrector.insert_after(
        last_element_range_with_trailing_comma(node),
        node.loc.end.source
      )
    end
  end
end

def last_element_range_with_trailing_comma(node)
  trailing_comma_range = last_element_trailing_comma_range(node)
  if trailing_comma_range
    children(node).last.source_range.join(trailing_comma_range)
  else
    children(node).last.source_range
  end
end

def last_element_trailing_comma_range(node)
  range = range_with_surrounding_space(
    range: children(node).last.source_range,
    side: :right
  ).end.resize(1)
  range.source == ',' ? range : nil
end