test.host in Rspec testing Rails redirect

Question

Here's a line from my test.rb environnment file in a Rails 3.1.12 app:

config.action_mailer.default_url_options = config.action_controller.default_url_options = { :host => "127.0.0.1", :port => 3000 }

Now here's the test I make:

subject { get :success }
subject.should redirect_to(:home)

This produces an error:

Failure/Error: subject.should redirect_to(:home)
       Expected response to be a redirect to <http://127.0.0.1:3000/> but was a redirect to <http://test.host/>

What did I do wrong? Or else, where the testing host be configured?

Here's the spec_helper.rb file for complete reference.

# This file is copied to spec/ when you run 'rails generate rspec:install'
ENV["RAILS_ENV"] = 'test'
require File.expand_path("../../config/environment", __FILE__)
require 'rspec/rails'
require 'rspec/autorun'
require 'capybara/rspec'

# Requires supporting ruby files with custom matchers and macros, etc,
# in spec/support/ and its subdirectories.
Dir[Rails.root.join("spec/support/**/*.rb")].each {|f| require f}

RSpec.configure do |config|
  # ## Mock Framework
  #
  # If you prefer to use mocha, flexmock or RR, uncomment the appropriate line:
  #
  # config.mock_with :mocha
  # config.mock_with :flexmock
  # config.mock_with :rr

  # Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
  config.fixture_path = "#{::Rails.root}/spec/fixtures"

  # If you're not using ActiveRecord, or you'd prefer not to run each of your
  # examples within a transaction, remove the following line or assign false
  # instead of true.
  config.use_transactional_fixtures = true

  # If true, the base class of anonymous controllers will be inferred
  # automatically. This will be the default behavior in future versions of
  # rspec-rails.
  config.infer_base_class_for_anonymous_controllers = false

  # Run specs in random order to surface order dependencies. If you find an
  # order dependency and want to debug it, you can fix the order by providing
  # the seed, which is printed after each run.
  #     --seed 1234
  config.order = "random"
end
Capybara.configure do |config|
  config.app_host    = 'http://127.0.0.1'
  config.server_port = 3000
end

Answer 1

To set the app host and server port with Capybara add the following lines to your spec/spec_helper.rb file

Capybara.configure do |config|
  config.app_host   = 'http://127.0.0.1'
  config.server_port = 3000
end

-- Edit #1

A nice overview of testing domains is available at http://blog.joncairns.com/2012/12/testing-domains-with-rails-and-test-unit/