ActionDispatch::Cookies::CookieJar#deleted? predicate method.

Necessary in controller tests to determine if the CookieJar will delete
the given cookie.

actionpack/lib/action_dispatch/middleware/cookies.rb

@@ -191,6 +191,15 @@ module ActionDispatch
         value
       end
 
+      # Whether the given cookie is to be deleted by this CookieJar.
+      # Like <tt>[]=</tt>, you can pass in an options hash to test if a
+      # deletion applies to a specific <tt>:path</tt>, <tt>:domain</tt> etc.
+      def deleted?(key, options = {})
+        options.symbolize_keys!
+        handle_options(options)
+        @delete_cookies[key.to_s] == options
+      end
+
       # Removes all cookies on the client machine by calling <tt>delete</tt> for each cookie
       def clear(options = {})
         @cookies.each_key{ |k| delete(k, options) }

actionpack/test/dispatch/cookies_test.rb

@@ -245,6 +245,17 @@ class CookiesTest < ActionController::TestCase
     assert_cookie_header "user_name=; path=/beaten; expires=Thu, 01-Jan-1970 00:00:00 GMT"
   end
 
+  def test_deleted_cookie_predicate
+    cookies.delete("user_name")
+    assert cookies.deleted?("user_name")
+    assert_equal false, cookies.deleted?("another")
+  end
+
+  def test_deleted_cookie_predicate_with_mismatching_options
+    cookies.delete("user_name", :path => "/path")
+    assert_equal false, cookies.deleted?("user_name", :path => "/different")
+  end
+
   def test_cookies_persist_throughout_request
     response = get :authenticate
     assert response.headers["Set-Cookie"] =~ /user_name=david/