test.rb

gem "rails", "3.2.19"

require "rails"
require "action_controller/railtie"

class TestApp < Rails::Application
  config.root = File.dirname(__FILE__)
  config.session_store :cookie_store, key: "cookie_store_key"
  config.secret_token    = "1111111111111111111111111111111111111111111111111111111111111111111111111secret_token"
  config.secret_key_base = "secret_key_base"

  config.logger = Logger.new($stdout)
  Rails.logger  = config.logger

  routes.draw do
    scope "(:locale)", locale: /en|pt-BR/, module: :public do
      get "/passing" => "test#passing"
      get "/failing" => "test#failing"
      get "foo" => "test#foo"
    end
  end
end

module Public; end

class Public::TestController < ActionController::Base
  include Rails.application.routes.url_helpers

  before_filter :set_locale

  def set_locale(locale = :"pt-BR")
    @locale = locale
  end

  def failing
    # I18n.with_locale("en") do
    #   foo_path
    # end

    set_locale("en")
    foo_path
    set_locale

    render text: foo_path
  end

  def passing
    render text: foo_path
  end

  def default_url_options(options={})
    { locale: @locale }
  end
end

require "minitest/autorun"
require "rack/test"

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

class BugTest < Minitest::Test
  include Rack::Test::Methods

  def test_failing
    get "pt-BR/failing"
    assert_equal "/pt-BR/foo", last_response.body
  end

  def test_passing
    get "pt-BR/passing"
    assert_equal "/pt-BR/foo", last_response.body
  end

  private
    def app
      Rails.application
    end
end