Adding missing failure file and test.

lib/devise/failure.rb

@@ -0,0 +1,25 @@
+module Devise
+  module Failure
+
+    # Failure application that will be called every time :warden is thrown from
+    # any strategy or hook. Responsible for redirect the user to the sign in
+    # page based on current scope and mapping.
+    def self.call(env)
+      options = env['warden.options']
+      params = options[:params] || {}
+      scope = options[:scope]
+      mapping = Devise.mappings[scope]
+
+      redirect_path = "/#{mapping.as}/#{mapping.path_names[:sign_in]}"
+
+      headers = {}
+      headers["Location"] = redirect_path
+      headers["Location"] << "?" << Rack::Utils.build_query(params) unless params.empty?
+      headers["Content-Type"] = 'text/plain'
+
+      message = options[:message] || "You are being redirected to #{redirect_path}"
+
+      [302, headers, message]
+    end
+  end
+end

test/failure_test.rb

@@ -0,0 +1,34 @@
+require 'test/test_helper'
+
+class FailureTest < ActiveSupport::TestCase
+
+  def call_failure(env_params={})
+    env = {'warden.options' => {:scope => :user}.update(env_params)}
+    Devise::Failure.call(env)
+  end
+
+  test 'return 302 status' do
+    assert_equal 302, call_failure.first
+  end
+
+  test 'return redirect location based on mapping with params' do
+    assert_equal '/users/sign_in', call_failure.second['Location']
+  end
+
+  test 'add params to redirect location' do
+    location = call_failure(:params => {:test => true}).second['Location']
+    assert_equal '/users/sign_in?test=true', location
+  end
+
+  test 'set content type to default text/plain' do
+    assert_equal 'text/plain', call_failure.second['Content-Type']
+  end
+
+  test 'setup a default message' do
+    assert_equal 'You are being redirected to /users/sign_in', call_failure.last
+  end
+
+  test 'pass in a different message' do
+    assert_equal 'Hello world', call_failure(:message => 'Hello world').last
+  end
+end