module ActionDispatch::Assertions::ResponseAssertions

def assert_redirected_to(options = {}, message = nil)

assert_redirected_to %r(\Ahttp://example.org)
# Asserts that the redirection matches the regular expression

assert_redirected_to @customer
# Asserts that the redirection was to the URL for @customer

assert_redirected_to login_url
# Asserts that the redirection was to the named route login_url

assert_redirected_to controller: "weblog", action: "index"
# Asserts that the redirection was to the "index" action on the WeblogController

Asserts that the response is a redirect to a URL matching the given options. 
def assert_redirected_to(options = {}, message = nil)
  assert_response(:redirect, message)
  return true if options === @response.location
  redirect_is       = normalize_argument_to_redirection(@response.location)
  redirect_expected = normalize_argument_to_redirection(options)
  message ||= "Expected response to be a redirect to <#{redirect_expected}> but was a redirect to <#{redirect_is}>"
  assert_operator redirect_expected, :===, redirect_is, message
end

def assert_response(type, message = nil)

assert_response 401
# Asserts that the response code was status code 401 (unauthorized)

assert_response :redirect
# Asserts that the response was a redirection

See Rack::Utils::SYMBOL_TO_STATUS_CODE for a full list.
or its symbolic equivalent assert_response(:not_implemented).
You can also pass an explicit status number like assert_response(501)

* :error - Status code was in the 500-599 range
* :missing - Status code was 404
* :redirect - Status code was in the 300-399 range
* :success - Status code was in the 200-299 range

Asserts that the response is one of the following types: 
def assert_response(type, message = nil)
  message ||= generate_response_message(type)
  if RESPONSE_PREDICATES.keys.include?(type)
    assert @response.public_send(RESPONSE_PREDICATES[type]), message
  else
    assert_equal AssertionResponse.new(type).code, @response.response_code, message
  end
end

def code_with_name(code_or_name) 

def code_with_name(code_or_name)
  if RESPONSE_PREDICATES.values.include?("#{code_or_name}?".to_sym)
    code_or_name = RESPONSE_PREDICATES.invert["#{code_or_name}?".to_sym]
  end
  AssertionResponse.new(code_or_name).code_and_name
end

def generate_response_message(expected, actual = @response.response_code) 

def generate_response_message(expected, actual = @response.response_code)
  (+"Expected response to be a <#{code_with_name(expected)}>,"\
  " but was a <#{code_with_name(actual)}>").concat(location_if_redirected).concat(response_body_if_short)
end

def location_if_redirected 

def location_if_redirected
  return "" unless @response.redirection? && @response.location.present?
  location = normalize_argument_to_redirection(@response.location)
  " redirect to <#{location}>"
end

def normalize_argument_to_redirection(fragment) 

def normalize_argument_to_redirection(fragment)
  if Regexp === fragment
    fragment
  else
    handle = @controller || ActionController::Redirecting
    handle._compute_redirect_to_location(@request, fragment)
  end
end

def parameterize(value)

Proxy to to_param if the object will respond to it. 
def parameterize(value)
  value.respond_to?(:to_param) ? value.to_param : value
end

def response_body_if_short 

def response_body_if_short
  return "" if @response.body.size > 500
  "\nResponse body: #{@response.body}"
end