Sample Contract Class

encryption_contract.rb

require 'instance_method_validator'

module EncryptionContract

  def required_function_names
      [
      # The purpose of this function is self-evident, but in other
      # cases the methods would benefit from some explanation
      # that would be helpful to authors of new implementations,
      # such as defining correct behavior, format and data type
      # of arguments and return values.
      #
      # encrypt a string
      #
      # arg: the string to encrypt
      # returns: the encrypted string 
      'encrypt',
      
      # decrypts a string 
      #
      # arg: the string to decrypt
      # returns: the decrypted string 
      'decrypt',          # (encrpyted string)
    ]
  end

  
  def validate_contract(klass = self.class)
    InstanceMethodValidator.new(required_function_names).validate(klass)
  end
end