capybara_subdomains.rb

# spec/support/capybara.rb

require 'capybara/rspec'
require 'capybara/rails'

Capybara.javascript_driver = :webkit
Capybara.app_host = 'lvh.me'
Capybara.always_include_port = true

# spec/support/host_for_subdomains.rb

def hosted_domain(options = {})
  path = options[:path] || '/' # use root path by default
  subdomain = options[:subdomain].present? ? (options[:subdomain]+'.') : ''
  if example.metadata[:js]
    # figures out which port Capybara spun up on the "rails s -e test" command
    # ** note: on Capybara 2.x you can use Capybara.always_use_port in the spec_helper
    url = "http://#{subdomain}lvh.me#{path}"
  else
    url = "http://#{subdomain}example.com" + path
  end
end


# Usage example

def login_as_publisher(publisher=nil)
  @publisher = publisher
  @publisher ||= create :publisher
  visit hosted_domain path: new_publisher_session_path, subdomain: 'publisher'
  within '#loginform' do
    fill_in 'publisher_email', with: @publisher.email
    fill_in 'publisher_password', with: 'password'
    click_button 'Login'
  end
end