class Module

def alias_method_chain(target, feature)

so you can safely chain foo, foo?, and foo! with the same feature.

alias_method :foo?, :foo_with_feature?
alias_method :foo_without_feature?, :foo?

is equivalent to

alias_method_chain :foo?, :feature

Query and bang methods (foo?, foo!) keep the same punctuation:

And both aliases are set up for you.

alias_method_chain :foo, :feature

With this, you simply do:

alias_method :foo, :foo_with_feature
alias_method :foo_without_feature, :foo

Encapsulates the common pattern of: 
def alias_method_chain(target, feature)
  # Strip out punctuation on predicates or bang methods since
  # e.g. target?_without_feature is not a valid method name.
  aliased_target, punctuation = target.to_s.sub(/([?!=])$/, ''), $1
  yield(aliased_target, punctuation) if block_given?
  with_method, without_method = "#{aliased_target}_with_#{feature}#{punctuation}", "#{aliased_target}_without_#{feature}#{punctuation}"
  alias_method without_method, target
  alias_method target, with_method
  case
    when public_method_defined?(without_method)
      public target
    when protected_method_defined?(without_method)
      protected target
    when private_method_defined?(without_method)
      private target
  end
end