1 files changed, 12 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/request/session.rb b/actionpack/lib/action_dispatch/request/session.rb
index 7bc812fd22..6d911a75f1 100644
--- a/actionpack/lib/action_dispatch/request/session.rb
+++ b/actionpack/lib/action_dispatch/request/session.rb
@@ -127,6 +127,18 @@ module ActionDispatch
         @delegate.delete key.to_s
       end
 
+      def fetch(key, default=nil)
+        if self.key?(key)
+          self[key]
+        elsif default
+          self[key] = default
+        elsif block_given?
+          self[key] = yield(key)
+        else
+          raise KeyError
+        end
+      end
+
       def inspect
         if loaded?
           super