class Module

def alias_method_chain(target, feature)

so you can safely chain foo, foo?, foo! and/or 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:

comes with Ruby 2.0 or newer instead.
NOTE: This method is deprecated. Please use Module#prepend that
def alias_method_chain(target, feature)
  ActiveSupport::Deprecation.warn("alias_method_chain is deprecated. Please, use Module#prepend instead. From module, you can access the original method using super.")
  # Strip out punctuation on predicates, bang or writer 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 = "#{aliased_target}_with_#{feature}#{punctuation}"
  without_method = "#{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