From 4837bb0a4e5a1ea00e732f48ee2acef90606a31e Mon Sep 17 00:00:00 2001
From: Scott Jacobsen <jacobsenscott@yahoo.com>
Date: Tue, 3 Mar 2015 22:37:25 -0700
Subject: [PATCH] Allow objects to specify their devise scope.

Introspecting the scope of an object can make it difficult to use
wrapper patterns. See issue plataformatec/devise#3307 for an example.

Allow objects to specify their scope explicitly by implementing
`devise_scope`.
---
 lib/devise/mapping.rb | 1 +
 test/mapping_test.rb  | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/lib/devise/mapping.rb b/lib/devise/mapping.rb
index 5c40f762..af4a1412 100644
--- a/lib/devise/mapping.rb
+++ b/lib/devise/mapping.rb
@@ -31,6 +31,7 @@ module Devise
     # Receives an object and find a scope for it. If a scope cannot be found,
     # raises an error. If a symbol is given, it's considered to be the scope.
     def self.find_scope!(obj)
+      obj = obj.devise_scope if obj.respond_to?(:devise_scope)
       case obj
       when String, Symbol
         return obj.to_sym
diff --git a/test/mapping_test.rb b/test/mapping_test.rb
index d22bf0bc..2159997c 100644
--- a/test/mapping_test.rb
+++ b/test/mapping_test.rb
@@ -71,6 +71,12 @@ class MappingTest < ActiveSupport::TestCase
     assert_equal :user, Devise::Mapping.find_scope!(Class.new(User).new)
   end
 
+  test 'find scope uses devise_scope' do
+    user = User.new
+    def user.devise_scope; :special_scope; end
+    assert_equal :special_scope, Devise::Mapping.find_scope!(user)
+  end
+
   test 'find scope raises an error if cannot be found' do
     assert_raise RuntimeError do
       Devise::Mapping.find_scope!(String)