Fix NoMethodError in random_password

.gitignore

@@ -29,3 +29,4 @@ webrat.log
 
 # Generated test files
 tmp/*
+test/rails_app/tmp/

lib/devise_invitable/models.rb

@@ -397,8 +397,10 @@ def after_invitation_accepted(*args, &blk)
           # lower + upper case, a digit and a symbol.
           # For more unusual rules, this method can be overridden.
           def random_password
+            length = respond_to?(:password_length) ? password_length : Devise.password_length
+
             prefix = 'aA1!'
-            prefix + Devise.friendly_token(self.password_length.last-prefix.length)
+            prefix + Devise.friendly_token(length.last - prefix.length)
           end
       end
     end

test/models/invitable_test.rb

@@ -765,9 +765,15 @@ def assert_callbacks_status(callback, user, fired)
     assert user.errors.empty?
   end
 
-  test 'should set initial password following devise password_length' do
+  test 'should set initial password following Devise.password_length' do
+    user = User.invite!(email: 'valid@email.com')
+    assert_empty user.errors
+    assert_equal Devise.password_length.last, user.password.length
+  end
+
+  test 'should set initial passsword using :validatable with custom password_length' do
     user = Validatable.invite!(email: 'valid@email.com')
-    user.update_attributes(profile_id: 1)
     assert_empty user.errors
+    assert_equal Validatable.password_length.last, user.password.length
   end
 end