Required fields on encryptable

lib/devise/models/encryptable.rb

@@ -24,6 +24,14 @@ module Encryptable
         attr_accessor :password_confirmation
       end
 
+      module ModuleMethods
+        extend self
+
+        def required_fields
+          [:password_salt]
+        end
+      end
+
       # Generates password salt.
       def password=(new_password)
         self.password_salt = self.class.password_salt if new_password.present?
@@ -69,4 +77,4 @@ def password_salt
       end
     end
   end
-end
+end

test/models/encryptable_test.rb

@@ -64,4 +64,10 @@ def swap_with_encryptor(klass, encryptor, options={})
     admin.save
     assert_not admin.valid_password?('123456')
   end
+
+  test 'required_fields should contain the fields that Devise uses' do
+    assert_equal Devise::Models::Encryptable::ModuleMethods.required_fields, [
+      :password_salt
+    ]
+  end
 end