lib/rubocop/cop/style/empty_line_between_defs.rb


# encoding: utf-8

module RuboCop
  module Cop
    module Style
      # This cop checks whether method definitions are
      # separated by empty lines.
      class EmptyLineBetweenDefs < Cop
        include OnMethodDef
        MSG = 'Use empty lines between method definitions.'

        def on_method_def(node, _method_name, _args, _body)
          return unless node.parent && node.parent.begin_type?

          nodes = [prev_node(node), node]

          return unless nodes.all?(&method(:def_node?))
          return if blank_lines_between?(*nodes)
          return if nodes.all?(&:single_line?) &&
                    cop_config['AllowAdjacentOneLineDefs']

          add_offense(node, :keyword)
        end

        private

        def def_node?(node)
          return unless node
          node.def_type? || node.defs_type?
        end

        def blank_lines_between?(first_def_node, second_def_node)
          lines_between_defs(first_def_node, second_def_node).any?(&:blank?)
        end

        def prev_node(node)
          return nil unless node.sibling_index > 0

          node.parent.children[node.sibling_index - 1]
        end

        def lines_between_defs(first_def_node, second_def_node)
          line_range = def_end(first_def_node)..(def_start(second_def_node) - 2)

          processed_source.lines[line_range]
        end

        def def_start(node)
          node.loc.keyword.line
        end

        def def_end(node)
          node.loc.end.line
        end

        def autocorrect(node)
          prev_def = prev_node(node)
          end_pos = prev_def.loc.end.end_pos
          source_buffer = prev_def.loc.end.source_buffer
          newline_pos = source_buffer.source.index("\n", end_pos)
          newline = Parser::Source::Range.new(source_buffer,
                                              newline_pos,
                                              newline_pos + 1)
          ->(corrector) { corrector.insert_after(newline, "\n") }
        end
      end
    end
  end
end