class RuboCop::Cop::Naming::BinaryOperatorParameterName

def +(other); end
# good
def +(amount); end
# bad
@example
sole parameter named ‘other`.
This cop makes sure that certain binary operator methods have their

def on_def(node) 

def on_def(node)
  op_method_candidate?(node) do |name, arg|
    return unless op_method?(name)
    add_offense(arg, :expression, format(MSG, name))
  end
end

def op_method?(name) 

def op_method?(name)
  return false if BLACKLISTED.include?(name)
  name !~ /\A\w/ || OP_LIKE_METHODS.include?(name)
end