Add cancel to registrations controller as a way to delete information from session.

app/controllers/devise/registrations_controller.rb

@@ -1,5 +1,5 @@
 class Devise::RegistrationsController < ApplicationController
-  prepend_before_filter :require_no_authentication, :only => [ :new, :create ]
+  prepend_before_filter :require_no_authentication, :only => [ :new, :create, :cancel ]
   prepend_before_filter :authenticate_scope!, :only => [:edit, :update, :destroy]
   include Devise::Controllers::InternalHelpers
 
@@ -45,6 +45,14 @@ class Devise::RegistrationsController < ApplicationController
     sign_out_and_redirect(self.resource)
   end
 
+  # GET /resource/cancel
+  # Forces the session data which is usually expired after sign
+  # in to be expired now.
+  def cancel
+    expire_session_data_after_sign_in!
+    redirect_to new_registration_path(resource_name)
+  end
+
   protected
 
     # Build a devise resource passing in the session. Useful to move

lib/devise/rails/routes.rb

@@ -216,8 +216,15 @@ module ActionDispatch::Routing
       end
 
       def devise_registration(mapping, controllers) #:nodoc:
-        resource :registration, :only => [:new, :create, :edit, :update, :destroy], :path => mapping.path_names[:registration],
-                 :path_names => { :new => mapping.path_names[:sign_up] }, :controller => controllers[:registrations]
+        path_names = {
+          :new => mapping.path_names[:sign_up],
+          :cancel => mapping.path_names[:cancel]
+        }
+
+        resource :registration, :except => :show, :path => mapping.path_names[:registration],
+                 :path_names => path_names, :controller => controllers[:registrations] do
+          get :cancel
+        end
       end
 
       def devise_oauth_callback(mapping, controllers) #:nodoc:

test/integration/registerable_test.rb

@@ -150,4 +150,16 @@ class RegistrationTest < ActionController::IntegrationTest
 
     assert User.all.empty?
   end
+
+  test 'a user should be able to cancel sign up by deleting data in the session' do
+    get "/set"
+    assert_equal "something", @request.session["user_facebook_oauth_token"]
+
+    get "/users/sign_up"
+    assert_equal "something", @request.session["user_facebook_oauth_token"]
+
+    get "/users/cancel"
+    assert_nil @request.session["user_facebook_oauth_token"]
+    assert_redirected_to new_user_registration_path
+  end
 end

test/rails_app/app/controllers/home_controller.rb

@@ -4,4 +4,9 @@ class HomeController < ApplicationController
 
   def private
   end
+
+  def set
+    session["user_facebook_oauth_token"] = "something"
+    head :ok
+  end
 end

test/rails_app/config/routes.rb

@@ -39,9 +39,10 @@ Rails.application.routes.draw do
         :sign_in => "login", :sign_out => "logout",
         :password => "secret", :confirmation => "verification",
         :unlock => "unblock", :sign_up => "register",
-        :registration => "management"
+        :registration => "management", :cancel => "giveup"
       }
   end
 
+  match "/set", :to => "home#set"
   root :to => "home#index"
 end

test/routes_test.rb

@@ -86,6 +86,11 @@ class DefaultRoutingTest < ActionController::TestCase
     assert_recognizes({:controller => 'devise/registrations', :action => 'destroy'}, {:path => 'users', :method => :delete})
   end
 
+  test 'map cancel user registration' do
+    assert_recognizes({:controller => 'devise/registrations', :action => 'cancel'}, {:path => 'users/cancel', :method => :get})
+    assert_named_route "/users/cancel", :cancel_user_registration_path
+  end
+
   test 'map oauth callbacks' do
     assert_recognizes({:controller => 'devise/oauth_callbacks', :action => 'facebook'}, {:path => 'users/oauth/facebook/callback', :method => :get})
     assert_recognizes({:controller => 'devise/oauth_callbacks', :action => 'github'}, {:path => 'users/oauth/github/callback', :method => :get})
@@ -140,6 +145,11 @@ class CustomizedRoutingTest < ActionController::TestCase
   test 'map account with custom path name for registration' do
     assert_recognizes({:controller => 'devise/registrations', :action => 'new', :locale => 'en'}, '/en/accounts/management/register')
   end
+
+  test 'map account with custom path name for cancel registration' do
+    assert_recognizes({:controller => 'devise/registrations', :action => 'cancel', :locale => 'en'}, '/en/accounts/management/giveup')
+  end
+
 end
 
 class ScopedRoutingTest < ActionController::TestCase