A perfect ruby mock

perfect_mock.rb

# from http://taylor.fausak.me/2014/05/24/class-comparison-in-ruby/
require 'forwardable'

def fake(klass)
  Class.new(BasicObject) do
    eigenclass = class << self; self end
    eigenclass.extend Forwardable
    eigenclass.def_delegators klass, *%i[
      <
      <=
      <=>
      ==
      ===
      >
      >=
      __id__
      ancestors
      eql?
      equal?
      inspect
      name
      object_id
      to_s
    ]

    define_method :class do
      klass
    end

    define_method :inspect do
      "#<#{klass.name}:0x#{'%x' % (__id__ << 1)}>"
    end
    alias_method :to_s, :inspect

    define_method :instance_of? do |other|
      klass == other
    end

    define_method :is_a? do |other|
      klass >= other
    end
    alias_method :kind_of?, :is_a?
  end
end

# Usage
# FakeCheese = fake(Cheese)
# # => Cheese
# american = FakeCheese.new
# # => #<Cheese:0x7fd8e1e5ba48>