Make use of warden's scoped serialization

lib/devise.rb

@@ -421,6 +421,17 @@ module Devise
 
       Devise.mappings.each_value do |mapping|
         warden_config.scope_defaults mapping.name, :strategies => mapping.strategies
+
+        warden_config.serialize_into_session(mapping.name) do |record|
+          mapping.to.serialize_into_session(record)
+        end
+
+        warden_config.serialize_from_session(mapping.name) do |key|
+          # Previous versions contained an additional entry at the beginning of
+          # key with the record's class name.
+          args = key[-2, 2]
+          mapping.to.serialize_from_session(*args)
+        end
       end
 
       @@warden_config_block.try :call, Devise.warden_config

lib/devise/rails/warden_compat.rb

@@ -12,32 +12,3 @@ module Warden::Mixins::Common
     request.cookie_jar
   end
 end
-
-class Warden::SessionSerializer
-  def serialize(record)
-    klass = record.class
-    array = klass.serialize_into_session(record)
-    array.unshift(klass.name)
-  end
-
-  def deserialize(keys)
-    klass_name, *args = keys
-
-    begin
-      klass = ActiveSupport::Inflector.constantize(klass_name)
-      if klass.respond_to? :serialize_from_session
-        klass.serialize_from_session(*args)
-      else
-        Rails.logger.warn "[Devise] Stored serialized class #{klass_name} seems not to be Devise enabled anymore. Did you do that on purpose?"
-        nil
-      end
-    rescue NameError => e
-      if e.message =~ /uninitialized constant/
-        Rails.logger.debug "[Devise] Trying to deserialize invalid class #{klass_name}"
-        nil
-      else
-        raise
-      end
-    end
-  end
-end

test/integration/authenticatable_test.rb

@@ -333,22 +333,34 @@ class AuthenticationSessionTest < ActionDispatch::IntegrationTest
     assert_equal "Cart", @controller.user_session[:cart]
   end
 
-  test 'does not explode when invalid user class is stored in session' do
-    klass = User
-    paths = ActiveSupport::Dependencies.autoload_paths.dup
-
+  test 'does not explode when class name is still stored in session' do
+    # In order to test that old sessions do not break with the new scoped
+    # deserialization, we need to serialize the session the old way. This is
+    # done by removing the newly used scoped serialization method
+    # (#user_serialize) and bringing back the old uncsoped #serialize method
+    # that includes the record's class name in the serialization.
     begin
+      Warden::SessionSerializer.class_eval do
+        alias_method :original_serialize, :serialize
+        alias_method :original_user_serialize, :user_serialize
+        remove_method :user_serialize
+
+        def serialize(record)
+          klass = record.class
+          array = klass.serialize_into_session(record)
+          array.unshift(klass.name)
+        end
+      end
+
       sign_in_as_user
       assert warden.authenticated?(:user)
-
-      Object.send :remove_const, :User
-      ActiveSupport::Dependencies.autoload_paths.clear
-
-      visit "/users"
-      assert_not warden.authenticated?(:user)
     ensure
-      Object.const_set(:User, klass)
-      ActiveSupport::Dependencies.autoload_paths.replace(paths)
+      Warden::SessionSerializer.class_eval do
+        alias_method :serialize, :original_serialize
+        remove_method :original_serialize
+        alias_method :user_serialize, :original_user_serialize
+        remove_method :original_user_serialize
+      end
     end
   end