module RSpec::Mocks::TestDouble

def self.extend_onto(object, name=nil, stubs_and_options={})
  object.extend self
  object.send(:__initialize_as_test_double, name, stubs_and_options)
end

def ==(other)
  other == __mock_proxy
end

def __build_mock_proxy
  proxy = Proxy.new(self, @name, @options || {})
  proxy.as_null_object if null_object?
  proxy
end

def __initialize_as_test_double(name=nil, stubs_and_options={})
  @__null_object = false
  if name.is_a?(Hash) && stubs_and_options.empty?
    stubs_and_options = name
    @name = nil
  else
    @name = name
  end
  @options = extract_options(stubs_and_options)
  assign_stubs(stubs_and_options)
end

def __mock_proxy
  ::RSpec::Mocks.proxy_for(self)
end

def as_null_object
  @__null_object = true
  __mock_proxy.as_null_object
end

def assign_stubs(stubs)
  stubs.each_pair do |message, response|
    Mocks.allow_message(self, message).and_return(response)
  end
end

def extract_option(source, target, key, default=nil)
  if source[key]
    target[key] = source.delete(key)
  elsif default
    target[key] = default
  end
end

def extract_options(stubs_and_options)
  if stubs_and_options[:null_object]
    @null_object = stubs_and_options.delete(:null_object)
    RSpec.deprecate("double('name', :null_object => true)", :replacement => "double('name').as_null_object")
  end
  options = {}
  extract_option(stubs_and_options, options, :__declared_as, 'Mock')
  options
end

def initialize(name=nil, stubs_and_options={})
  __initialize_as_test_double(name, stubs_and_options)
end

def inspect
  "#<#{self.class}:#{sprintf '0x%x', self.object_id} @name=#{@name.inspect}>"
end

def method_missing(message, *args, &block)
  if __mock_proxy.null_object?
    case message
    when :to_int        then return 0
    when :to_a, :to_ary then return nil
    end
  end
  __mock_proxy.record_message_received(message, *args, &block)
  begin
    __mock_proxy.null_object? ? self : super
  rescue NameError
    # Required wrapping doubles in an Array on Ruby 1.9.2
    raise NoMethodError if [:to_a, :to_ary].include? message
    __mock_proxy.raise_unexpected_message_error(message, *args)
  end
end

def null_object?
  @__null_object
end

def respond_to?(message, incl_private=false)
  __mock_proxy.null_object? ? true : super
end

def to_s
  inspect.gsub('<','[').gsub('>',']')
end