Added check_model! method

lib/devise/models.rb

@@ -1,5 +1,8 @@
 module Devise
   module Models
+    class MissingAttribute < StandardError
+    end
+
     # Creates configuration values for Devise and for the given module.
     #
     #   Devise::Models.config(Devise::Authenticatable, :stretches, 10)
@@ -39,6 +42,16 @@ module Devise
       end
     end
 
+    def self.check_fields!(klass)
+      klass.devise_modules.each do |mod|
+        instance = klass.new
+
+        const_get(mod.to_s.classify)::ModuleMethods.required_fields.each do |field|
+          raise Devise::Models::MissingAttribute unless instance.respond_to?(field)
+        end
+      end
+    end
+
     # Include the chosen devise modules in your model:
     #
     #   devise :database_authenticatable, :confirmable, :recoverable

lib/devise/models/database_authenticatable.rb

@@ -27,6 +27,14 @@ module Devise
         attr_accessor :password_confirmation
       end
 
+      module ModuleMethods
+        extend self
+
+        def required_fields
+          [:encrypted_password, :email]
+        end
+      end
+
       # Generates password encryption based on the given value.
       def password=(new_password)
         @password = new_password

test/models_test.rb

@@ -107,3 +107,39 @@ class ActiveRecordTest < ActiveSupport::TestCase
     Admin.create!
   end
 end
+
+class CheckFieldsTest < ActiveSupport::TestCase
+  test 'checks if the class respond_to the required fields' do
+    Player = Class.new do
+      extend Devise::Models
+
+      def self.before_validation(x)
+      end
+
+      devise :database_authenticatable
+
+      attr_accessor :encrypted_password, :email
+    end
+
+    assert_nothing_raised Devise::Models::MissingAttribute do
+      Devise::Models.check_fields!(Player)
+    end
+  end
+
+  test 'raises Devise::Models::MissingAtrribute if the class doesn\'t respond_to one of the attributes' do
+    Clown = Class.new do
+      extend Devise::Models
+
+      def self.before_validation(instance)
+      end
+
+      devise :database_authenticatable
+
+      attr_accessor :encrypted_password
+    end
+
+    assert_raise Devise::Models::MissingAttribute do
+      Devise::Models.check_fields!(Clown)
+    end
+  end
+end