Attempt to recreate bug cited by @monfresh in artsy#53

spec/integration/grape_spec.rb

@@ -24,10 +24,48 @@ class TestGrapeApp < Grape::API
           { :meaning_of_life => 42 }.to_json
         end
       end
+
+      get "/mongers" do
+        garner.options({ :expires_in => 5.minutes }) do
+          Monger.all
+        end
+      end
     end
 
     TestGrapeApp.new
   end
 
   it_behaves_like "Rack::ConditionalGet server"
+
+  context "caching modified classes/objects" do
+    include Rack::Test::Methods
+
+    before(:each) do
+      @object = Monger.create!({ :name => "M1" })
+    end
+
+    it "does not raise error when underlying classes are changed" do
+      json = Monger.all.to_json
+      browser = Rack::Test::Session.new(TestGrapeApp.new)
+      browser.get "/mongers"
+      browser.last_response.should be_successful
+      browser.last_response.body.should == json
+
+      TestGrapeApp.reset!
+      class TestGrapeApp < Grape::API
+        helpers Garner::Mixins::Rack
+
+        format :json
+
+        get "/mongers" do
+          Monger.all
+        end
+      end
+
+      browser = Rack::Test::Session.new(TestGrapeApp.new)
+      browser.get "/mongers"
+      browser.last_response.should be_successful
+      browser.last_response.body.should == json
+    end
+  end
 end

spec/integration/mongoid_spec.rb

@@ -237,6 +237,31 @@
             end
           end
         end
+
+        context "caching modified classes/objects" do
+          before(:each) do
+            @object = Monger.create!({ :name => "M1" })
+          end
+
+          let(:cached_object_fetcher) do
+            lambda do
+              @app.garner.options({ :expires_in => 5.minutes }) do
+                Monger.all.as_json
+              end
+            end
+          end
+
+          it "does not raise error when underlying classes are changed" do
+            json = Monger.all.as_json
+            cached_object_fetcher.call.should == json
+
+            class Monger
+              field :foo, :type => Boolean
+            end
+
+            cached_object_fetcher.call.should == json            
+          end
+        end
       end
     end
   end