class RuboCop::Cop::Lint::ParenthesesAsGroupedExpression

def on_send(node)
  _receiver, method_name, *args = *node
  return if args.size > 1
  return if operator?(method_name) || node.asgn_method_call?
  return unless args.first && args.first.source.start_with?('(')
  space_length = spaces_before_left_parenthesis(node)
  return unless space_length > 0
  expr = args.first.source_range
  space_range =
    Parser::Source::Range.new(expr.source_buffer,
                              expr.begin_pos - space_length,
                              expr.begin_pos)
  add_offense(nil, space_range)
end

def spaces_before_left_parenthesis(node)
  receiver, method_name, _args = *node
  receiver_length = if receiver
                      receiver.source.length
                    else
                      0
                    end
  without_receiver = node.source[receiver_length..-1]
  # Escape question mark if any.
  method_regexp = Regexp.escape(method_name)
  match = without_receiver.match(/^\s*\.?\s*#{method_regexp}(\s+)\(/)
  match ? match.captures[0].length : 0
end