module Rubocop::Cop::Style::FavorOtherKeywordOverNegation

def check(node)
  condition, _body, _rest = *node
  # Look at last expression of contents if there's a parenthesis
  # around condition.
  condition = condition.children.last while condition.type == :begin
  if condition.type == :send
    _object, method = *condition
    if method == :! && !(node.loc.respond_to?(:else) && node.loc.else)
      add_offence(:convention, node.loc.expression, error_message)
    end
  end
end