class RuboCop::Cop::Style::For

allowed, however.
parameter. An each call with a block on a single line is always
preferred alternative is set in the EnforcedStyle configuration
This cop looks for uses of the for keyword, or each method. The

def on_block(node) 

def on_block(node)
  return if block_length(node) == 0
  method, _args, _body = *node
  return unless method.type == :send
  _receiver, method_name, *args = *method
  return unless method_name == :each && args.empty?
  if style == :for
    end_pos = method.source_range.end_pos
    range = Parser::Source::Range.new(processed_source.buffer,
                                      end_pos - EACH_LENGTH,
                                      end_pos)
    add_offense(range, range, 'Prefer `for` over `each`.') do
      opposite_style_detected
    end
  else
    correct_style_detected
  end
end

def on_for(node) 

def on_for(node)
  if style == :each
    add_offense(node, :keyword, 'Prefer `each` over `for`.') do
      opposite_style_detected
    end
  else
    correct_style_detected
  end
end